Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
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| tcc1p, a novel protein containing the tetratricopeptide repeat motif, interacts with tup1p to regulate morphological transition and virulence in candida albicans. | the transcriptional factor catup1p represses many genes involved in intracellular processes, including the yeast-hypha transition, in the human fungal pathogen candida albicans. using tandem affinity purification technology, we identified a novel protein that interacts with catup1p, named tcc1p (tup1p complex component). tcc1p is a c. albicans-specific protein with a 736-amino-acid polypeptide with four tetratricopeptide repeat (tpr) motifs in the n-terminal portion. tcc1p formed a protein compl ... | 2006 | 16998076 |
| compact, universal dna microarrays to comprehensively determine transcription-factor binding site specificities. | transcription factors (tfs) interact with specific dna regulatory sequences to control gene expression throughout myriad cellular processes. however, the dna binding specificities of only a small fraction of tfs are sufficiently characterized to predict the sequences that they can and cannot bind. we present a maximally compact, synthetic dna sequence design for protein binding microarray (pbm) experiments that represents all possible dna sequence variants of a given length k (that is, all 'k-me ... | 2006 | 16998473 |
| a gene-specific requirement for fact during transcription is related to the chromatin organization of the transcribed region. | the fact complex stimulates transcription elongation on nucleosomal templates. in vivo experiments also involve fact in the reassembly of nucleosomes traversed by rna polymerase ii. since several features of chromatin organization vary throughout the genome, we wondered whether fact is equally required for all genes. we show in this study that the in vivo depletion of spt16, one of the subunits of saccharomyces cerevisiae fact, strongly affects transcription of three genes, gal1, pho5, and kluyv ... | 2006 | 17000768 |
| modulation of abeta42 low-n oligomerization using a novel yeast reporter system. | while traditional models of alzheimer's disease focused on large fibrillar deposits of the abeta42 amyloid peptide in the brain, recent work suggests that the major pathogenic effects may be attributed to sds-stable oligomers of abeta42. these abeta42 oligomers represent a rational target for therapeutic intervention, yet factors governing their assembly are poorly understood. | 2006 | 17002801 |
| functional interaction between human herpesvirus 6 immediate-early 2 protein and ubiquitin-conjugating enzyme 9 in the absence of sumoylation. | the immediate-early 2 (ie2) protein of human herpesvirus 6 is a potent transactivator of cellular and viral promoters. to better understand the biology of ie2, we generated a lexa-ie2 fusion protein and screened, using the yeast two-hybrid system, a jurkat t-cell cdna library for proteins that could interact with ie2. the most frequently isolated ie2-interacting protein was the human ubiquitin-conjugating enzyme 9 (ubc9), a protein involved in the small ubiquitin-like modifier (sumo) conjugation ... | 2006 | 17005699 |
| the mrg domain of human mrg15 uses a shallow hydrophobic pocket to interact with the n-terminal region of pam14. | mrg15 is a transcription factor expressed in a variety of human tissues, and its orthologs have been found in many other eukaryotes which constitute the mrg protein family. it plays a vital role in embryonic development and cell proliferation, and is involved in cellular senescence. the c-terminal part of mrg15 forms a conserved mrg domain which is involved in interactions with the tumor suppressor protein retinoblastoma and a nucleoprotein pam14 during transcriptional regulation. we report here ... | 2006 | 17008723 |
| measuring "free" iron levels in caenorhabditis elegans using low-temperature fe(iii) electron paramagnetic resonance spectroscopy. | oxidative stress, caused by free radicals within the body, has been associated with the process of aging and many human diseases. because free radicals, in particular superoxide, are difficult to measure, an alternative indirect method for measuring oxidative stress levels has been used successfully in escherichia coli and yeast. this method is based on a proposed connection between elevated superoxide levels and release of iron from solvent-exposed [4fe-4s] enzyme clusters that eventually leads ... | 2006 | 17010298 |
| nonsense-mediated mrna decay: target genes and functional diversification of effectors. | recent genome-wide identification of nonsense-mediated mrna decay (nmd) targets in yeast, fruitfly and human cells has provided insight into the biological functions and evolution of this mrna quality control mechanism, revealing that nmd post-transcriptionally regulates an important fraction of the transcriptome. nmd targets are associated with a broad range of biological processes, but most of these targets are not encoded by orthologous genes across different species. yeast and fruitfly nmd e ... | 2006 | 17010613 |
| secretory expression of synthetic human fas ligand extracellular domain gene in pichia pastoris: influences of tag addition and n-glycosylation site deletion, and development of a purification method. | human fas ligand is a medically important membrane glycoprotein that induces the apoptosis of harmful cells. a new secretory expression and purification method was devised for the production of a large amount of recombinant human fas ligand extracellular domain (hfaslecd) by pichia pastoris. the expression plasmid containing a synthetic hfaslecd gene designed using yeast optimal codons was constructed for the secretion of hfaslecd. the secreted product exhibited the specific binding activity tow ... | 2006 | 17011210 |
| mtorc2 caught in a sinful akt. | the target of rapamycin (tor), a central controller of cell growth, is found in two distinct, highly conserved multiprotein complexes. three recent papers in cell (jacinto et al., 2006), developmental cell (shiota et al., 2006; this issue), and current biology (frias et al., 2006) shed light on mtor complex 2 (mtorc2) composition and in vivo function. an important new finding is that mtorc2 determines akt/pkb substrate specificity rather than absolute activity. | 2006 | 17011481 |
| long-range downstream enhancers are essential for pax6 expression. | pax6 is a developmental control gene with an essential role in development of the eye, brain and pancreas. pax6, as many other developmental regulators, depends on a substantial number of cis-regulatory elements in addition to its promoters for correct spatiotemporal and quantitative expression. here we report on our analysis of a set of mice transgenic for a modified yeast artificial chromosome carrying the human pax6 locus. in this 420 kb yac a taugfp-ires-neomycin reporter cassette has been i ... | 2006 | 17014839 |
| an artificially constructed de novo human chromosome behaves almost identically to its natural counterpart during metaphase and anaphase in living cells. | human artificial chromosomes (hacs) are promising reagents for the analysis of chromosome function. while hacs are maintained stably, the segregation mechanisms of hacs have not been investigated in detail. to analyze hacs in living cells, we integrated 256 copies of the lac operator into a precursor yeast artificial chromosome (yac) containing alpha-satellite dna and generated green fluorescent protein (gfp)-tagged hacs in ht1080 cells expressing a gfp-lac repressor fusion protein. time-lapse a ... | 2006 | 17015481 |
| the common phospholipid-binding activity of the n-terminal domains of pex1 and vcp/p97. | pex1 is a type ii aaa-atpase that is indispensable for biogenesis and maintenance of the peroxisome, an organelle responsible for the primary metabolism of lipids, such as beta-oxidation and lipid biosynthesis. recently, we demonstrated a striking structural similarity between its n-terminal domain and those of other membrane-related aaa-atpases, such as valosine-containing protein (p97). the n-terminal domain of valosine-containing protein serves as an interface to its adaptor proteins p47 and ... | 2006 | 17018057 |
| mechanism of actin filament turnover by severing and nucleation at different concentrations of adf/cofilin. | adf/cofilins are key regulators of actin dynamics during cellular motility, yet their precise role and mechanism of action are shrouded in ambiguity. direct observation of actin filaments by evanescent wave microscopy showed that cofilins from fission yeast and human do not increase the rate that pointed ends of actin filaments shorten beyond the rate for adp-actin subunits, but both cofilins inhibit elongation and subunit dissociation at barbed ends. direct observation also showed that cofilins ... | 2006 | 17018289 |
| human papillomavirus type 5 e6 oncoprotein represses the transforming growth factor beta signaling pathway by binding to smad3. | mechanisms of cellular transformation associated with human papillomavirus type 5 (hpv5), which is responsible for skin carcinomas in epidermodysplasia verruciformis (ev) patients, are poorly understood. using a yeast two-hybrid screening and molecular and cellular biology experiments, we found that hpv5 oncoprotein e6 interacts with smad3, a key component in the transforming growth factor beta1 (tgf-beta1) signaling pathway. hpv5 e6 inhibits smad3 transactivation by destabilizing the smad3/smad ... | 2006 | 17020941 |
| estrogenic activity of uv filter mixtures. | uv-absorbing chemicals (uv filters) are widely used for protection against uv radiation in sunscreens and in a variety of cosmetic products and materials. depending on the breadth and factor of uv protection, they are added as single compounds or as a combination thereof. some uv filters have estrogenic activity, but their activity and interactions in mixtures are largely unknown. in this work, we analyzed 8 commonly used uv filters, which are pure or partial heralpha agonists, for their estroge ... | 2006 | 17027055 |
| functional characterization of human and cynomolgus monkey udp-glucuronosyltransferase 1a6 enzymes. | udp-glucuronosyltransferase 1a6 (ugt1a6) is a major isoform in the human liver that glucuronidates numerous drugs, environmental chemicals and endogenous substrates. in this study, human and cynomolgus monkey ugt1a6 cdnas (humugt1a6 and monugt1a6, respectively) were cloned, and the corresponding proteins were heterologously expressed in yeast cells to identify the functions of primate ugt1a6s. the enzymatic properties of ugt1a6 proteins were characterized by the kinetic analysis of serotonin (5- ... | 2006 | 17027947 |
| centromere-proximal crossovers are associated with precocious separation of sister chromatids during meiosis in saccharomyces cerevisiae. | in most organisms, meiotic chromosome segregation is dependent on crossovers (cos), which enable pairs of homologous chromosomes to segregate to opposite poles at meiosis i. in mammals, the majority of meiotic chromosome segregation errors result from a lack of cos between homologs. observations in homo sapiens and drosophila melanogaster have revealed a second class of exceptional events in which a co occurred near the centromere of the missegregated chromosome. we show that in wild-type strain ... | 2006 | 17028345 |
| influence of silicon on cobalt, zinc, and magnesium in baker's yeast, saccharomyces cerevisiae. | silicon (si, as silicate) is involved in numerous important structure and function roles in a wide range of organisms, including man. silicate availability influences metal concentrations within various cell and tissue types, but, as yet, clear mechanisms for such an influence have been discovered only within the diatoms and sponges. in this study, the influence of silicate on the intracellular accumulation of metals was investigated in baker's yeast (saccharomyces cerevisiae). it was found that ... | 2006 | 17028383 |
| evidence for an early gene duplication event in the evolution of the mitochondrial transcription factor b family and maintenance of rrna methyltransferase activity in human mttfb1 and mttfb2. | most metazoans have two nuclear genes encoding orthologues of the well-characterized saccharomyces cerevisiae mitochondrial transcription factor b (sc-mttfb). this class of transcription factors is homologous to the bacterial ksga family of rrna methyltransferases, which in escherichia coli dimethylates adjacent adenine residues in a stem-loop of the 16s rrna. this posttranscriptional modification is conserved in most metazoan cytoplasmic and mitochondrial rrnas. homo sapiens mitochondrial trans ... | 2006 | 17031457 |
| functional analyses of glycyl-trna synthetase mutations suggest a key role for trna-charging enzymes in peripheral axons. | charcot-marie-tooth disease type 2d (cmt2d) and distal spinal muscular atrophy type v (dsma-v) are axonal neuropathies characterized by a phenotype that is more severe in the upper extremities. we previously implicated mutations in the gene encoding glycyl-trna synthetase (gars) as the cause of cmt2d and dsma-v. gars is a member of the family of aminoacyl-trna synthetases responsible for charging trna with cognate amino acids; gars ligates glycine to trna(gly). here, we present functional analys ... | 2006 | 17035524 |
| functional studies of the ssk1p response regulator protein of candida albicans as determined by phenotypic analysis of receiver domain point mutants. | the candida albicans response regulator protein ssk1p regulates oxidant adaptation through the mapk hog1 pathway. deletion mutants lacking ssk1 are oxidant sensitive in vitro and are killed more than wild-type (wt) cells by human neutrophils. furthermore, the mutants are avirulent in an invasive murine model, and unable to adhere to human esophageal cells. transcriptional profiling has indicated that approximately 25% of all changes occur in genes encoding cell wall and stress adaptation functio ... | 2006 | 17038117 |
| ret finger protein enhances mbd2- and mbd4-dependent transcriptional repression. | we recently demonstrated that mbd4 possesses the ability to repress transcription through methyl-cpg and is associated with methylated promoters in the cdkn2a and mlh1 genes. in order to further investigate the role of mbd4 in methylation-based transcriptional repression, a yeast two-hybrid screening was performed, and the ret finger protein (rfp) was found to be one of the major proteins that interact with the transcriptional repression domain in mbd4. the effect of the mbd4-mediated transcript ... | 2006 | 17049487 |
| yeast and filamentous fungi as model organisms in microbody research. | yeast and filamentous fungi are important model organisms in microbody research. the value of these organisms as models for higher eukaryotes is underscored by the observation that the principles of various aspects of microbody biology are strongly conserved from lower to higher eukaryotes. this has allowed to resolve various peroxisome-related functions, including peroxisome biogenesis disorders in man. this paper summarizes the major advances in microbody research using fungal systems and spec ... | 2006 | 17050005 |
| calcium stiffens archaeal rad51 recombinase from methanococcus voltae for homologous recombination. | archaeal rada or rad51 recombinases are close homologues of eukaryal rad51 and dmc1. these and bacterial reca orthologues play a key role in dna repair by forming helical nucleoprotein filaments in which a hallmark strand exchange reaction between homologous dna substrates occurs. recent studies have discovered the stimulatory role by calcium on human and yeast recombinases. here we report that the strand exchange activity but not the atpase activity of an archaeal rada/rad51 recombinase from me ... | 2006 | 17050545 |
| the single subunit nadh dehydrogenase reduces generation of reactive oxygen species from complex i. | using rat dopaminergic and human neuroblastoma cell lines transduced with the ndi1 gene encoding the internal nadh dehydrogenase (ndi1) from saccharomyces cerevisiae, we investigated reactive oxygen species (ros) generation caused by complex i inhibition. incubation of non-transduced cells with rotenone elicited oxidative damage to mitochondrial dna as well as lipid peroxidation. in contrast, oxidative stress was significantly decreased when the cells were transduced with ndi1. furthermore, mito ... | 2006 | 17055488 |
| morphogenesis and cell cycle progression in candida albicans. | candida albicans, an opportunistic human pathogen, displays three modes of growth: yeast, pseudohyphae and true hyphae, all of which differ both in morphology and in aspects of cell cycle progression. in particular, in hyphal cells, polarized growth becomes uncoupled from other cell cycle events. yeast or pseudohyphae that undergo a cell cycle delay also exhibit polarized growth, independent of cell cycle progression. the spitzenkörper, an organelle composed of vesicles associated with hyphal ti ... | 2006 | 17055773 |
| interaction between glycogenin and glycogen synthase. | glycogen synthase plays a key role in regulating glycogen metabolism. in a search for regulators of glycogen synthase, a yeast two-hybrid study was performed. two glycogen synthase-interacting proteins were identified in human skeletal muscle, glycogenin-1, and nebulin. the interaction with glycogenin was found to be mediated by the region of glycogenin which contains the 33 cooh-terminal amino acid residues. the regions in glycogen synthase containing both nh2- and cooh-terminal phosphorylation ... | 2006 | 17055998 |
| gas6 and protein s. vitamin k-dependent ligands for the axl receptor tyrosine kinase subfamily. | gas6 and protein s are two homologous secreted proteins that depend on vitamin k for their execution of a range of biological functions. a discrete subset of these functions is mediated through their binding to and activation of the receptor tyrosine kinases axl, sky and mer. furthermore, a hallmark of the gas6-axl system is the unique ability of gas6 and protein s to tether their non receptor-binding regions to the negatively charged membranes of apoptotic cells. numerous studies have shown the ... | 2006 | 17064312 |
| role of nadph oxidase 4 in lipopolysaccharide-induced proinflammatory responses by human aortic endothelial cells. | we investigated the role of nadph oxidase 4 (nox4) on lipopolysaccharide (lps)-induced proinflammatory responses by human aortic endothelial cells (haecs). | 2006 | 17064675 |
| identification of human trna:m5c methyltransferase catalysing intron-dependent m5c formation in the first position of the anticodon of the pre-trna leu (caa). | we identified a human orthologue of trna:m5c methyltransferase from saccharomyces cerevisiae, which has been previously shown to catalyse the specific modification of c34 in the intron-containing yeast pre-trna leu (caa). using transcripts of intron-less and intron-containing human pre-trna leu (caa) genes as substrates, we have shown that m5c34 is introduced only in the intron-containing trna precursors when the substrates were incubated in the hela extract. m5c34 formation depends on the nucle ... | 2006 | 17071714 |
| construction of yeast artificial chromosome libraries from pathogens and nonmodel organisms. | many infectious diseases of global impact are caused by parasites. this includes diseases with protozoan etiology, such as malaria, african sleeping sickness, chagas disease, toxoplasmosis, and amoebiasis, as well as diseases caused by metazoa, such as river blindness, schistosomiasis, ecchinococcosis, and ascariasis. combined, parasitic diseases affect more than half the world's human population and are responsible for decreased gross national products and billions of dollars in lost earnings. ... | 2006 | 17071969 |
| production of yeast artificial chromosome transgenic mice by pronuclear injection of one-cell embryos. | the generation of transgenic animals has become an important tool in helping to understand the roles of genes in maintaining health and the roles of human gene variants in contributing to disease susceptibility. in order to model the subtleties of gene expression, which include tissue-specific transcriptional regulation and alternative gene splicing, it is useful to include entire genes that comprise all of the exons, introns, and regulatory sequences required for proper gene expression. a signi ... | 2006 | 17071980 |
| longin-like folds identified in chips and duf254 proteins: vesicle trafficking complexes conserved in eukaryotic evolution. | eukaryotic protein trafficking pathways require specific transfer of cargo vesicles to different target organelles. a number of vesicle trafficking and membrane fusion components participate in this process, including various tethering factor complexes that interact with small gtpases prior to snare-mediated vesicle fusion. in saccharomyces cerevisiae a protein complex of mon1 and ccz1 functions with the small gtpase ypt7 to mediate vesicle trafficking to the vacuole. mon1 belongs to duf254 foun ... | 2006 | 17075139 |
| sel1l, the homologue of yeast hrd3p, is involved in protein dislocation from the mammalian er. | protein quality control in the endoplasmic reticulum (er) involves recognition of misfolded proteins and dislocation from the er lumen into the cytosol, followed by proteasomal degradation. viruses have co-opted this pathway to destroy proteins that are crucial for host defense. examination of dislocation of class i major histocompatibility complex (mhc) heavy chains (hcs) catalyzed by the human cytomegalovirus (hcmv) immunoevasin us11 uncovered a conserved complex of the mammalian dislocation m ... | 2006 | 17043138 |
| functional relationships between rad18 and wrnip1 in vertebrate cells. | the wrnip1 protein interacts with wrn, the product of the causative gene for werner syndrome. mutation of the saccharomyces cerevisiae gene mgs1, the yeast counterpart of wrnip1, confers synthetic lethality with mutation of rad18. to examine the functional relationship between wrnip1 and rad18 in higher eukaryotic cells, we generated wrnip1-/-/-/rad18-/- lines from chicken dt40 cells and compared them with single mutant cell lines. unlike the corresponding yeast mutant, wrnip1-/-/-/rad18-/- cell ... | 2006 | 17077513 |
| human cystathionine beta-synthase is a target for sumoylation. | cystathionine beta-synthase (cbs) catalyzes the first irreversible step in the transsulfuration pathway and commits the toxic metabolite, homocysteine, to the synthesis of cysteine. mutations in cbs are the most common cause of severe hereditary hyperhomocysteinemia. the molecular basis of the organ-specific pathologies associated with cbs deficiency is unknown as is the significance of the reported interaction between cbs and huntingtin protein. in this study, we have used the yeast two-hybrid ... | 2006 | 17087506 |
| diversity of trna genes in eukaryotes. | we compare the diversity of chromosomal-encoded transfer rna (trna) genes from 11 eukaryotes as identified by trnascan-se of their respective genomes. they include the budding and fission yeast, worm, fruit fly, fugu, chicken, dog, rat, mouse, chimp and human. the number of trna genes are between 170 and 570 and the number of trna isoacceptors range from 41 to 55. unexpectedly, the number of trna genes having the same anticodon but different sequences elsewhere in the trna body (defined here as ... | 2006 | 17088292 |
| cernunnos-xlf, a recently identified non-homologous end-joining factor required for the development of the immune system. | the analysis of immune deficiency conditions in humans has recently allowed the identification of a novel factor, cernunnos, involved in dna repair and required during the development of the immune system. the present review will focus on the information and new questions provided by the discovery of cernunnos. | 2006 | 17088645 |
| expression of a novel marine viral single-chain serine palmitoyltransferase and construction of yeast and mammalian single-chain chimera. | the genus coccolithovirus is a recently discovered group of viruses that infect the globally important marine calcifying microalga emiliania huxleyi. surprisingly, the viral genome contains a cluster of putative sphingolipid biosynthetic genes not found in other viral genus. to address the role of these genes in viral pathogenesis, the ehv050 gene predicted to encode a serine palmitoyltransferase (spt), the first and rate-limiting enzyme of sphingolipid biosynthesis, was expressed and characteri ... | 2006 | 17090526 |
| the role of nad+ dependent histone deacetylases (sirtuins) in ageing. | histone deacetylases (hdacs) are enzymes that are able to deacetylate lysine side chains in histones and certain non-histone proteins which leads to altered states of conformation and activity for the proteins in question. three classes of histone deacetylases have been recognized in humans. class i and ii are zinc-dependent amidohydrolases and eleven subtypes have been discovered (hdac1-11). class iii enzymes depend in their catalysis on nad(+) and subsequently, o-acetyl adp ribose and nicotina ... | 2006 | 17100594 |
| the dna helicase chlr1 is required for sister chromatid cohesion in mammalian cells. | it has recently been suggested that the saccharomyces cerevisiae protein chl1p plays a role in cohesion establishment. here, we show that the human atp-dependent dna helicase chlr1 is required for sister chromatid cohesion in mammalian cells. localization studies show that chlr1 diffusely coats mitotic chromatin in prophase and then translocates from the chromatids to concentrate at the spindle poles during the transition to metaphase. depletion of chlr1 protein by rna interference results in mi ... | 2006 | 17105772 |
| beta-lapachone activates a mre11p-tel1p g1/s checkpoint in budding yeast. | beta-lapachone is an anticancer agent that selectively induces cell death in several human cancer cells. the mechanism of beta-lapachone cytotoxicity is not yet fully understood. here we report that beta-lapachone treatment delayed cell cycle progression at the g(1)/s transition, incremented phosphorylation of the rad53p checkpoint kinase and decreased cell survival in the budding yeast saccharomyces cerevisiae. furthermore, beta-lapachone induced phosphorylation of histone h2a at serine 129. th ... | 2006 | 17106258 |
| systematic screening of polyphosphate (poly p) levels in yeast mutant cells reveals strong interdependence with primary metabolism. | inorganic polyphosphate (poly p) occurs universally in all organisms from bacteria to man. it functions, for example, as a phosphate and energy store, and is involved in the activation and regulation of proteins. despite its ubiquitous occurrence and important functions, it is unclear how poly p is synthesized or how poly p metabolism is regulated in higher eukaryotes. this work describes a systematic analysis of poly p levels in yeast knockout strains mutated in almost every non-essential gene. | 2006 | 17107617 |
| human shprh is a ubiquitin ligase for mms2-ubc13-dependent polyubiquitylation of proliferating cell nuclear antigen. | human shprh gene is located at the 6q24 chromosomal region, and loss of heterozygosity in this region is seen in a wide variety of cancers. shprh is a member of the swi/snf family of atpases/helicases, and it possesses a c(3)hc(4) ring motif characteristic of ubiquitin ligase proteins. in both of these features, shprh resembles the yeast rad5 protein, which, together with mms2-ubc13, promotes replication through dna lesions via an error-free postreplicational repair pathway. genetic evidence in ... | 2006 | 17108083 |
| human arrest defective 1 acetylates and activates beta-catenin, promoting lung cancer cell proliferation. | arrest defective 1 (ard1), an acetyltransferase, is essential for the yeast life cycle. although its human homologue (hard1) has been identified, its biological functions in human cells remain unclear. in the present study, we examined the biological function of hard1. in h1299 and a549 lung cancer cells, hard1-silencing rna inhibited cell proliferation and induced g(1) arrest. cyclin d1 was also found to be down-regulated in these growth-arrested cells, and the ectopic expression of cyclin d1 r ... | 2006 | 17108104 |
| the rat apg3p/aut1p homolog is upregulated by ischemic preconditioning in the retina. | retinas can be protected from subsequent severe ischemic injury by ischemic preconditioning. ischemic preconditioning is dependent on gene expression and protein synthesis; however, it is not clear which genes are important in this process. in this study, we have identified and characterized the rat homolog of yeast apg3p/aut1p, an important autophagy protein encoded by the autophagy 3-like (apg3l) gene. we have also further characterized the homologous human apg3l gene. | 2006 | 17110912 |
| human wapl is a cohesin-binding protein that promotes sister-chromatid resolution in mitotic prophase. | the linkage between duplicated chromosomes (sister chromatids) is established during s phase by the action of cohesin, a multisubunit complex conserved from yeast to humans. most cohesin dissociates from chromosome arms when the cell enters mitotic prophase, leading to the formation of metaphase chromosomes with two cytologically discernible chromatids. this process is known as sister-chromatid resolution. although two mitotic kinases have been implicated in this process, it remains unknown exac ... | 2006 | 17112726 |
| wapl controls the dynamic association of cohesin with chromatin. | cohesin establishes sister-chromatid cohesion from s phase until mitosis or meiosis. to allow chromosome segregation, cohesion has to be dissolved. in vertebrate cells, this process is mediated in part by the protease separase, which destroys a small amount of cohesin, but most cohesin is removed from chromosomes without proteolysis. how this is achieved is poorly understood. here, we show that the interaction between cohesin and chromatin is controlled by wapl, a protein implicated in heterochr ... | 2006 | 17113138 |
| suppression of spontaneous genome rearrangements in yeast dna helicase mutants. | saccharomyces cerevisiae mutants lacking two of the three dna helicases sgs1, srs2, and rrm3 exhibit slow growth that is suppressed by disrupting homologous recombination. cells lacking sgs1 and rrm3 accumulate gross-chromosomal rearrangements (gcrs) that are suppressed by the dna damage checkpoint and by homologous recombination-defective mutations. in contrast, rrm3, srs2, and srs2 rrm3 mutants have wild-type gcr rates. gcr types in helicase double mutants include telomere additions, transloca ... | 2006 | 17114288 |
| elucidation of the function of type 1 human methionine aminopeptidase during cell cycle progression. | processing of the n-terminal initiator methionine is an essential cellular process conserved from prokaryotes to eukaryotes. the enzymes that remove n-terminal methionine are known as methionine aminopeptidases (metaps). human metap2 has been shown to be required for the proliferation of endothelial cells and angiogenesis. the physiological function of metap1, however, has remained elusive. in this report we demonstrate that a family of inhibitors with a core structure of pyridine-2-carboxylic a ... | 2006 | 17114291 |
| new vectors for simplified construction of brdu-incorporating strains of saccharomyces cerevisiae. | the thymidine analogue brdu is a powerful tool for analysing nucleotide incorporation in studies of dna replication or repair. s. cerevisiae lacks the thymidine salvage pathway that enables efficient cellular uptake and incorporation of thymidine analogues into dna. recent in vivo reconstitution of this pathway in yeast by high-level expression of herpes simplex virus thymidine kinase (hsv-tk) or combined expression of hsv-tk and human equilibrative nucleoside transporter (hent1) has enabled ana ... | 2006 | 17083135 |
| arabidopsis nrp1 and nrp2 encode histone chaperones and are required for maintaining postembryonic root growth. | nucleosome assembly protein1 (nap1) is conserved from yeast to human and was proposed to act as a histone chaperone. while budding yeast contains a single nap1 gene, multicellular organisms, including plants and animals, contain several nap1 and nap1-related protein (nrp) genes. however, the biological role of these genes has been largely unexamined. here, we show that, in arabidopsis thaliana, simultaneous knockout of the two nrp genes, nrp1 and nrp2, impaired postembryonic root growth. in the ... | 2006 | 17122067 |
| acute and subchronic toxicity studies on sel-plex, a standardized, registered high-selenium yeast. | selenium has been recognized as an essential nutrient for human health; however, its bioavailability is primarily dependent upon the type of selenium, elemental versus organic. in geographic areas low in selenium, there is the potential for animals (including humans) to become selenium deficient and this potential deficiency can be remedied by consumption of exogenous selenium, including selenium-enriched yeast (saccharomyces cerevisiae) that contains high levels of organic selenium (e.g., selen ... | 2006 | 17132605 |
| jun activation domain-binding protein 1 binds smad5 and inhibits bone morphogenetic protein signaling. | bone morphogenetic proteins (bmps) play an important role in the development and the homeostasis and pathology of cartilage tissue, particularly in the differentiation and anabolic activity of chondrocytes. the present study was undertaken to identify binding partners of the smad proteins, the intracellular mediators of bmp activity, which might actively modify bmp signaling in chondrocytes. | 2006 | 17133595 |
| cytochrome b(5) is a major reductant in vivo of human indoleamine 2,3-dioxygenase expressed in yeast. | the evolutionary relationship of indoleamine 2,3-dioxygenase (ido) to some gastropod myoglobins suggests that ido may undergo autoxidation in vivo such that one or more currently unidentified electron donors are required to maintain ido heme iron in the active, ferrous state. to evaluate this hypothesis we have used yeast knockout mutants in combination with a recently developed yeast growth assay for ido activity in vivo to demonstrate a role for cytochrome b(5) and cytochrome b(5) reductase in ... | 2006 | 16574111 |
| from yeast ammonium transporters to rhesus proteins, isolation and functional characterization. | saccharomyces cerevisiae possesses three ammonium transporters from the mep/amt family involved in ammonium acquisition and retention. we have shown that rh proteins are structurally related to mep/amt proteins and that human rhag and rhcg perform bi-directional ammonium transport upon heterologous expression in yeast. using yeast as an expression tool, we have started a structure-function analysis of distinct members from the mep/amt/rh super-family. | 2006 | 16574457 |
| new insights into the control of mrna decapping. | mrna decapping irreversibly targets mrnas for fast decay. cap removal is catalyzed by decapping protein dcp2 but also requires dcp1. recently, two groups have provided a first glimpse of the regulation mechanism of this crucial step in gene expression. resolution of the yeast dcp2 structure has enabled identification of the residues that are important for its interaction with dcp1. however, the human decapping machinery seems to be more complex because a third component, hedls, is required for a ... | 2006 | 16580207 |
| methylarsonous acid transport by aquaglyceroporins. | many mammals methylate trivalent inorganic arsenic in liver to species that are released into the bloodstream and excreted in urine and feces. this study addresses how methylated arsenicals pass through cell membranes. we have previously shown that aquaglyceroporin channels, including escherichia coli glpf, saccharomyces cerevisiae fps1p, aqp7, and aqp9 from rat and human, conduct trivalent inorganic arsenic [as(iii)] as arsenic trioxide, the protonated form of arsenite. one of the initial produ ... | 2006 | 16581540 |
| the high-mobility-group domain of sox proteins interacts with dna-binding domains of many transcription factors. | sox proteins are widely believed to team up with other transcription factors as partner proteins to perform their many essential functions during development. in this study, yeast two-hybrid screens identified transcription factors as a major group of interacting proteins for sox8 and sox10. interacting transcription factors were very similar for these two group e sox proteins and included proteins with different types of dna-binding domains, such as homeodomain proteins, zinc finger proteins, b ... | 2006 | 16582099 |
| structure of human ubiquitin-conjugating enzyme e2 g2 (ube2g2/ubc7). | the human ubiquitin-conjugating enzyme e2 g2 (ube2g2/ubc7) is involved in protein degradation, including a process known as endoplasmic reticulum-associated degradation (erad). the crystal structure of human ube2g2/ubc7 was solved at 2.56 angstroms resolution. the ube2g2 structure comprises a single domain consisting of an antiparallel beta-sheet with four strands, five alpha-helices and two 3(10)-helices. structural comparison of human ube2g2 with yeast ubc7 indicated that the overall structure ... | 2006 | 16582478 |
| localization of the translational guanine nucleotide exchange factor eif2b: a common theme for gefs? | the eukaryotic initiation factor 2b (eif2b) serves an essential recycling function in protein synthesis. as the guanine nucleotide exchange factor for eif2, it recycles eif2 from a gdp to a gtp bound form that is competent for translation initiation. stress-dependent controls target this eif2b-recycling step allowing a reprogramming of the global gene expression profile. in addition, a human disease, leukoencephalopathy with vanishing white matter (vwm), is caused by mutations in the eif2b subun ... | 2006 | 16582624 |
| systematic identification of human mitochondrial disease genes through integrative genomics. | the majority of inherited mitochondrial disorders are due to mutations not in the mitochondrial genome (mtdna) but rather in the nuclear genes encoding proteins targeted to this organelle. elucidation of the molecular basis for these disorders is limited because only half of the estimated 1,500 mitochondrial proteins have been identified. to systematically expand this catalog, we experimentally and computationally generated eight genome-scale data sets, each designed to provide clues as to mitoc ... | 2006 | 16582907 |
| the spen homolog msx2-interacting nuclear target protein interacts with the e2 ubiquitin-conjugating enzyme ubch8. | the nuclear matrix protein msx2-interacting nuclear target protein (mint) is a transcription factor that regulates the expression of key transcriptional effectors in diverse signaling pathways. to further understand the function and mechanism of the mint-mediated transcription regulation, the yeast two-hybrid system was employed to screen proteins that interact with the c-terminal fragment of mint. from a cdna library of human lymph nodes, a cdna encoding the ubiquitin-conjugating enzyme ubch8 w ... | 2006 | 16583136 |
| inhibition of clinical and environmental cryptococcus neoformans isolates by two brazilian killer yeasts. | two killer yeast strains (hb55 and hb88) capable of inhibiting human pathogenic fungi were isolated from leaves of hibiscus rosa-sinensis in brazil. these isolates were identified by conventional methods and sequencing of the d1/d2 region of the 26s rdna as kodamaea ohmeri. they inhibited all cryptococcus neoformans (vars. neoformans, grubii and gattii) strains tested, including reference, clinical and environmental isolates. the killer phenotype was not cured by thermal treatment. | 2006 | 16598831 |
| a high mobility group protein binds to long cag repeat tracts and establishes their chromatin organization in saccharomyces cerevisiae. | long cag repeat tracts cause human hereditary neurodegenerative diseases and have a propensity to expand during parental passage. unusual physical properties of cag repeat tracts are thought to contribute to their instability. we investigated whether their unusual properties alter the organization of cag repeat tract chromatin. we report that cag repeat tracts, embedded in yeast chromosomes, have a noncanonical chromatin organization. digestion of chromatin with the restriction enzyme fnu4hi rev ... | 2006 | 16603770 |
| a specific catalytic subunit isoform of protein kinase ck2 is required for phosphorylation of the repressor nrg1 in saccharomyces cerevisiae. | protein kinase ck2 is highly conserved in eukaryotes and plays roles in many different cellular processes. ck2 is a tetramer comprising two catalytic and two regulatory subunits. most organisms have two major isoforms of the catalytic subunit, and evidence suggests strongly overlapping function. in the yeast saccharomyces cerevisiae, ck2 is essential for viability, and either catalytic subunit isoform, cka1 or cka2, suffices, but previous genetic evidence suggests that the isoforms have some dis ... | 2006 | 16607517 |
| [expression of human lnalpha4lg4-5 in pichia yeast]. | to carry out the secretive expression of human laminin alpha4 chain lg4-5 module (hlnalpha4lg4-5), recombinant expression plasmid ppiczalphaa-lg45 was constructed by inserting of hlnalpha4lg4-5 cdna into yeast expression vector ppiczaa. the hlnalpha4lg4-5 protein was expressed in gs115 pichia yeast strain after induced by methanol, and purified target protein can obviously promote the expansion and adhesion of 293 cells. | 2006 | 16607948 |
| novel susceptibility genes in inflammatory bowel disease. | the inflammatory bowel disease, crohn's disease and ulcerative colitis, are polygenic disorders with important environmental interactions. to date, the most widely adopted approach to identifying susceptibility genes in complex diseases has involved genome wide linkage studies followed by studies of positional candidate genes in loci of interest. this review encompasses data from studies into novel candidate genes implicated in the pathogenesis of inflammatory bowel disease. novel techniques to ... | 2006 | 16610046 |
| recombinant expression systems for allergen vaccines. | allergen immunotherapy of future is likely to be based on allergy vaccines that contain engineered allergens modified to abolish or substantially reduce their ige-binding activity in order to remove the risk of unwanted anaphylactic responses. the development of efficient systems for the production of recombinant allergens in sufficient quantities is requirement for establishing use of engineered allergens as components of allergy vaccines. this review outlines relative advantages and disadvanta ... | 2006 | 16613564 |
| dietary nucleotides and human immune cells. ii. modulation of pbmc growth and cytokine secretion. | the immune system is dependent on purines and pyrimidines as building blocks for dna and rna synthesis to enable rapid cell proliferation and protein synthesis. emerging evidence suggests that dietary nucleotides optimize immune function. we investigated whether growth and function of human immune cells were affected by an exogenous source of nucleotides during specific antigen challenge. | 2006 | 16615178 |
| casein kinase i epsilon associates with and phosphorylates the tight junction protein occludin. | occludin is an integral-membrane protein that contributes to tight junction function. we have identified casein kinase i epsilon (cki epsilon) as a binding partner for the c-terminal cytoplasmic domain of occludin by yeast two-hybrid screening. cki epsilon phosphorylated occludin and co-localised and co-immunoprecipitated with occludin from human endothelial cells. amino acids 265-318 of occludin were sufficient for cki epsilon binding and phosphorylation. deletion of the c-terminal 48 amino aci ... | 2006 | 16616143 |
| identification of the key lmo2-binding determinants on ldb1. | the overexpression of lim-only protein 2 (lmo2) in t-cells, as a result of chromosomal translocations, retroviral insertion during gene therapy, or in transgenic mice models, leads to the onset of t-cell leukemias. lmo2 comprises two protein-binding lim domains that allow lmo2 to interact with multiple protein partners, including lim domain-binding protein 1 (ldb1, also known as clim2 and nli), an essential cofactor for lmo proteins. sequestration of ldb1 by lmo2 in t-cells may prevent it bindin ... | 2006 | 16616188 |
| reconstitution of cd39 in liposomes amplifies nucleoside triphosphate diphosphohydrolase activity and restores thromboregulatory properties. | cd39 (nucleoside triphosphate diphosphohydrolase [ntpdase-1]) expressed on the luminal surface of endothelial cells rapidly metabolizes extracellular adenosine triphosphate (atp) and adenosine diphosphate (adp) to adenosine monophosphate (amp), and abrogates platelet reactivity. optimization of cd39 enzymatic activity appears dependent upon the expression of both transmembrane domains within plasma membranes. thus, motivation exists to examine therapeutic antiplatelet formulations that consist o ... | 2006 | 16616242 |
| the role of human nucleoside transporters in cellular uptake of 4'-thio-beta-d-arabinofuranosylcytosine and beta-d-arabinosylcytosine. | 4'-thio-beta-d-arabinofuranosyl cytosine (tarac) is in phase i development for treatment of cancer. in human equilibrative nucleoside transporter (hent) 1-containing cem cells, initial rates of uptake (10 microm; picomoles per microliter of cell water per second) of [3h]tarac and [3h]1-beta-d-arabinofuranosyl cytosine (arac) were low (0.007 +/- 003 and 0.034 +/- 0.003, respectively) compared with that of [3h]uridine (0.317 +/- 0.048), a highactivity hent1 permeant. in hent1- and hent2-containing ... | 2006 | 16617163 |
| dysbindin structural homologue ck1bp is an isoform-selective binding partner of human casein kinase-1. | casein kinase-1 is a family of ubiquitous eukaryotic protein kinases that frequently function in tandem with the ubiquitin modification system to modulate protein turnover and trafficking. in alzheimer's disease, these enzymes colocalize with ubiquitinated lesions, including neurofibrillary tangles and granulovacuolar degeneration bodies, suggesting they also play a role in disease pathogenesis. to identify binding partners that potentially regulate or recruit these enzymes toward disease lesion ... | 2006 | 16618118 |
| genomic characterization of pos5, the saccharomyces cerevisiae mitochondrial nadh kinase. | disruption of the saccharomyces cerevisiae mitochondrial nadh kinase pos5 increases the mitochondrial mutation rate 50-fold. whereas most multicellular eukaryotic genomes have one nadh kinase gene, the yeast genome contains three distinct genes encoding nad/h kinase activity. to determine if all three genes are essential for viability we constructed combinations of gene knockouts. we show that only the pos5deltautr1delta combination is synthetically lethal, demonstrating an essential overlapping ... | 2006 | 16621727 |
| erk8 down-regulates transactivation of the glucocorticoid receptor through hic-5. | extracellular signal-regulated kinase 8 (erk8) is the most recently identified member of the erk subfamily of mapks. although other members of the erk subfamily are established regulators of signaling pathways involved in cell growth and/or differentiation, less is known about erk8. to understand the cellular function of erk8, a yeast two-hybrid screen of a human lung library was performed to identify binding partners. one binding partner identified was hic-5 (also known as ara55), a multiple li ... | 2006 | 16624805 |
| evidence from knockout mice against physiologically significant aquaporin 8-facilitated ammonia transport. | aquaporin (aqp)8-facilitated transport of nh(3) has been suggested recently by increased nh(3) permeability in xenopus oocytes and yeast expressing human or rat aqp8. we tested the proposed roles of aqp8-facilitated nh(3) transport in mammalian physiology by comparative phenotype studies in wild-type vs. aqp8-null mice. aqp8-facilitated nh(3) transport was confirmed in mammalian cell cultures expressing rat or mouse aqp8, in which the fluorescence of a ph-sensing yellow fluorescent protein was m ... | 2006 | 16624991 |
| both normal and polyglutamine- expanded ataxin-7 are components of tftc-type gcn5 histone acetyltransferase- containing complexes. | sca7 (spinocerebellar ataxia type 7) is a neurodegenerative disorder caused by a cag repeat expansion in the sca7 gene that leads to elongation of a polyglutamine tract in ataxin-7, a protein of unknown function. sgf73, a putative yeast orthologue of ataxin-7, has been identified as a new component of the yeast saga (spt/ada/gcn5 acetyltransferase) multisubunit complex, a co-activator required for the transcription of a subset of rna polymerase ii-dependent genes. we show here that ataxin-7 is a ... | 2006 | 16626296 |
| antimicrobial activity of an abiotic host defense peptide mimic. | bacterial drug resistance is emerging as one of the most significant challenges to human health. antimicrobial peptides (amps), which are produced by many tissues and cell types of invertebrates, insects, and humans, as part of their innate immune system, have attracted considerable interest as alternative antibiotics. interest in novel mimics of amps has increased greatly over the last few years. this report details a new amp mimic, based on phenylene ethynylene, with improved antimicrobial act ... | 2006 | 16626628 |
| suppressed disassembly of autolyzing p94/capn3 by n2a connectin/titin in a genetic reporter system. | p94/calpain 3 is a skeletal muscle-specific member of the ca(2+)-regulated cytosolic cysteine protease family, the calpains. defective p94 protease activity originating from gene mutations causes a muscular dystrophy called calpainopathy, indicating the indispensability of p94 for muscle survival. because of the existence of the p94-specific regions is1 and is2, p94 undergoes very rapid and exhaustive autolysis. to elucidate the physiological relevance of this unique activity, the autolytic prof ... | 2006 | 16627476 |
| ubc9 interacts with sox4 and represses its transcriptional activity. | sox4 is a member of sox transcriptional factor family that is crucial for many cellular processes. in this study, a yeast two-hybrid screening of human mammary cdna library identified human ubiquitin-conjugating enzyme 9 (hubc9) that interacted with sox4. this interaction was confirmed by gst pull-down in vitro and co-immunoprecipitation assays in vivo. deletion mapping demonstrated that hmg-box domain of sox4 is required to mediate the interaction with ubc9 in yeast. furthermore, confocal micro ... | 2006 | 16631117 |
| identification and estrogenic characterization of impurities in commercial bisphenol a diglycidyl ether (badge). | a sample of commercial badge was fractioned by hplc and eight impurities including novel propyl derivatives (2), (5) and (6) were identified by nmr spectrometry, fab-ms and gc-ms. the estrogenicity, both agonist and antagonist, of fractions containing these impurities was measured with a yeast two-hybrid assay incorporating the human (her alpha) and a competitive binding assay for her alpha (elisa). in the yeast two-hybrid assay, estrogenic antagonist activity was found in two fractions, while e ... | 2006 | 16631231 |
| fumagillin suppresses hiv-1 infection of macrophages through the inhibition of vpr activity. | hiv-1 viral protein r (vpr) is one of the human immunodeficiency virus type 1 encoded proteins that have important roles in viral pathogenesis. however, no clinical drug for aids therapy that targets vpr has been developed. here, we have established a screening system to isolate vpr inhibitors using budding yeast cells. we purified a vpr inhibitory compound from fungal metabolites and identified it as fumagillin, a chemical already known to be a potent inhibitor of angiogenesis. fumagillin not o ... | 2006 | 16631749 |
| a probabilistic dynamical model for quantitative inference of the regulatory mechanism of transcription. | quantitative estimation of the regulatory relationship between transcription factors and genes is a fundamental stepping stone when trying to develop models of cellular processes. this task, however, is difficult for a number of reasons: transcription factors' expression levels are often low and noisy, and many transcription factors are post-transcriptionally regulated. it is therefore useful to infer the activity of the transcription factors from the expression levels of their target genes. | 2006 | 16632490 |
| sugar-dependent1 encodes a patatin domain triacylglycerol lipase that initiates storage oil breakdown in germinating arabidopsis seeds. | triacylglycerol hydrolysis (lipolysis) plays a pivotal role in the life cycle of many plants by providing the carbon skeletons and energy that drive postgerminative growth. despite the physiological importance of this process, the molecular mechanism is unknown. here, a genetic screen has been used to identify arabidopsis thaliana mutants that exhibit a postgerminative growth arrest phenotype, which can be rescued by providing sugar. seventeen sugar-dependent (sdp) mutants were isolated, and six ... | 2006 | 16473965 |
| mdm38 interacts with ribosomes and is a component of the mitochondrial protein export machinery. | saccharomyces cerevisiae mdm38 and ylh47 are homologues of human letm1, a protein implicated in wolf-hirschhorn syndrome. we analyzed the function of mdm38 and ylh47 in yeast mitochondria to gain insight into the role of letm1. we find that mdm38delta mitochondria have reduced amounts of certain mitochondrially encoded proteins and low levels of complex iii and iv and accumulate unassembled atp6 of complex v of the respiratory chain. mdm38 is especially required for efficient transport of atp6 a ... | 2006 | 16476776 |
| establishment and characterization of human urothelial cancer xenografts in severe combined immunodeficient mice. | to establish and characterize a murine xenograft model of human urothelial cancer in severe combined immunodeficient (scid) mice for therapeutic simulation. | 2006 | 16448432 |
| transport characteristics of mammalian rh and rh glycoproteins expressed in heterologous systems. | the development and use of heterologous expression systems is critical for deciphering the function of mammalian rh and rh-glycoproteins. the studies here use xenopus oocytes, well known for their ability to readily traffic and express difficult membrane proteins, and s. cerevisiae wild-type strains and mutants that are defective in ammonium transport. data obtained in both of these expression systems revealed that mammalian rh-glycoprotein-mediated transport (rhag, rhbg, and rhcg) is an electro ... | 2006 | 16563829 |
| biological gas channels for nh3 and co2: evidence that rh (rhesus) proteins are co2 channels. | physiological evidence from our laboratory indicates that amt/mep proteins are gas channels for nh3, the first biological gas channels to be described. this view has now been confirmed by structural evidence and is displacing the previous belief that amt/mep proteins were active transporters for the nh4+ ion. still disputed is the physiological substrate for rh proteins, the only known homologues of amt/mep proteins. many think they are mammalian ammonium (nh4+ or nh3) transporters. following mo ... | 2006 | 16563833 |
| from bacteria to man: archaic proton-dependent peptide transporters at work. | uptake of nutrients into cells is essential to life and occurs in all organisms at the expense of energy. whereas in most prokaryotic and simple eukaryotic cells electrochemical transmembrane proton gradients provide the central driving force for nutrient uptake, in higher eukaryotes it is more frequently coupled to sodium movement along the transmembrane sodium gradient, occurs via uniport mechanisms driven by the substrate gradient only, or is linked to the countertransport of a similar organi ... | 2006 | 16565475 |
| identification of new human pregnane x receptor ligands among pesticides using a stable reporter cell system. | pregnane x receptor (pxr, nr1i2) is activated by various chemically unrelated compounds, including environmental pollutants and drugs. we proceeded here to in vitro screening of 28 pesticides with a new reporter system that detects human pregnane x receptor (hpxr) activators. the cell line was obtained by a two-step stable transfection of cervical cancer hela cells. the first transfected cell line, hg5ln, contained an integrated luciferase reporter gene under the control of a gal4 yeast transcri ... | 2006 | 16565514 |
| prokaryotic and eukaryotic monothiol glutaredoxins are able to perform the functions of grx5 in the biogenesis of fe/s clusters in yeast mitochondria. | the saccharomyces cerevisiae monothiol glutaredoxin grx5 participates in the mitochondrial biogenesis of iron-sulfur clusters. grx5 homologues exist in organisms from bacteria to humans. chicken (cgrx5) and human (hgrx5) homologues contain a mitochondrial targeting sequence, suggesting a mitochondrial localization for these two proteins. we have compartmentalized the escherichia coli and synechocystis sp. homologues, and also cgrx5 and hgrx5, in the mitochondrial matrix of a yeast grx5 mutant. a ... | 2006 | 16566929 |
| physiological and functional interactions between tcf4 and daxx in colon cancer cells. | daxx, a human cell death-associated protein, was isolated as a tcf4-interacting protein, using a yeast two-hybrid screen. co-immunoprecipitation in hek-293t cells and yeast two-hybrid screen in y190 cells were performed to identify the interaction between tcf4 with daxx and to map the binding regions of tcf4. in the nucleus, daxx reduced dna binding activity of tcf4 and repressed tcf4 transcriptional activity. overexpression of daxx altered the expression of genes downstream of tcf4, including c ... | 2006 | 16569639 |
| effects of single nucleotide polymorphisms in human n-acetyltransferase 2 on metabolic activation (o-acetylation) of heterocyclic amine carcinogens. | n-acetyltransferase 2 (nat2) catalyzes the o-acetylation of n-hydroxy heterocyclic amines such as n-hydroxy-2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (n--oh--meiqx) and n-hydroxy-2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine (n--oh --phip) to dna binding metabolites that initiate mutagenesis and carcinogenesis. nat2 acetylator phenotype is associated with increased cancer risk. single nucleotide polymorphisms (snps) have been identified in the nat2 coding region. although the effects of t ... | 2006 | 16570281 |
| yeast prion-protein, sup35, fibril formation proceeds by addition and substraction of oligomers. | in analogy to human prions, a domain of the translation-termination protein in saccharomyces cerevisiae, sup35, can switch its conformation from a soluble functional state, [psi-], to a conformation, [psi+], that facilitates aggregation and impairs its native function. overexpression of the molecular chaperone hsp104 abolishes the [psi+] phenotype and restores the normal function of sup35. we have recently shown that hsp104 interacts preferably with low oligomeric species of a sup35 derived pept ... | 2006 | 16570324 |
| oncogenic activity of cdc6 through repression of the ink4/arf locus. | the ink4/arf locus encodes three tumour suppressors (p15(ink4b), arf and p16(ink4a)) and is among the most frequently inactivated loci in human cancer. however, little is known about the mechanisms that govern the expression of this locus. here we have identified a putative dna replication origin at the ink4/arf locus that assembles a multiprotein complex containing cdc6, orc2 and mcms, and that coincides with a conserved noncoding dna element (regulatory domain rd(ink4/arf)). targeted and local ... | 2006 | 16572177 |
| identification of novel genes expressed during rhabdomyosarcoma differentiation using cdna microarrays. | rhabdomyosarcomas (rms) are highly aggressive tumors that are thought to arise as a consequence of the regulatory disruption of the growth and differentiation of skeletal muscle progenitor cells. normal myogenesis is characterized by the expression of the myogenic regulatory factor gene family but, despite their expression in rms, these tumor cells fail to complete the latter stages of myogenesis. the rms cell line rd-a was treated with 12-o-tetradecanoylphorbol-13-acetate to induce differentiat ... | 2006 | 16669873 |
| mutational analysis of the intramembranous h10 loop of yeast nhx1 reveals a critical role in ion homoeostasis and vesicle trafficking. | yeast nhx1 [na+(k+)/h+ exchanger 1] is an intracellular na+(k+)/h+ exchanger, localizing to the late endosome where it is important for ion homoeostasis and vesicle trafficking. phylogenetic analysis of nhe (na+/h+ exchanger) sequences has identified orthologous proteins, including hsnhe6 (human nhe6), hsnhe7 and hsnhe9 of unknown physiological role. these appear distinct from well-studied mammalian plasma membrane isoforms (nhe1-nhe5). to explore the differences between plasma membrane and intr ... | 2006 | 16671892 |