| sense from nonsense: rna editing in mitochondria of kinetoplastid protozoa and slime molds. | | 1995 | 7781060 |
| site-specific initiation of dna replication within the non-transcribed spacer of physarum rdna. | physarum polycephalum rrna genes are found on extrachromosomal 60 kb linear palindromic dna molecules. previous work using electron microscope visualization suggested that these molecules are duplicated from one of four potential replication origins located in the 24 kb central non-transcribed spacer [vogt and braun (1977) eur. j. biochem., 80, 557-566]. considering the controversy on the nature of the replication origins in eukaryotic cells, where both site-specific or delocalized initiations h ... | 1995 | 7784195 |
| the actin-binding properties of the physarum actin-fragmin complex. regulation by calcium, phospholipids, and phosphorylation. | the actin-binding properties of the actin-fragmin complex from physarum polycephalum microplasmodia were investigated with respect to regulation by ca2+, phospholipids, and phosphorylation of the actin subunit by the endogenous actin-fragmin kinase. fragmin possesses two high affinity actin-binding sites and probably also a third, low affinity site. its nucleating and f-actin severing activities are inhibited by phosphatidylinositol 4,5-bisphosphate (pip2). actin-fragmin specifically binds pip2 ... | 1995 | 7852332 |
| [mitochondrial nuclear division and mitochondriokinesis]. | | 1994 | 7855301 |
| actin-binding proteins in cell motility. | | 1994 | 7860217 |
| phytosterols are present in pneumocystis carinii. | although originally classified as a protozoan, pneumocystis carinii is now considered to have fungal characteristics. drugs typically used for the treatment of fungal infections target ergosterol. because p. carinii is an important pathogen in aids and other immunocompromised patients, knowledge of the sterol content of this organism may be useful as a basis for developing new treatment strategies or for improving diagnosis. p. carinii organisms were harvested from infected rat lungs and were pu ... | 1994 | 7872743 |
| a non-cycling mitotic cyclin in the naturally synchronous cell cycle of physarum polycephalum. | a universal model of the control of the cell cycle in eukaryotic organisms has emerged from the discovery that mpf (maturation or mitosis promoting factor) is a heterodimer consisting of a catalytic subunit (p34cdc2) and a regulatory subunit (mitotic cyclin) encoded by a pair of conserved genes. a prominent feature of the periodic activation of the protein kinase p34cdc2 is the gradual accumulation of cyclin in interphase and its abrupt degradation in mitosis, which is believed to be required fo ... | 1994 | 7889999 |
| two early replicated, developmentally controlled genes of physarum display different patterns of dna replication by two-dimensional agarose gel electrophoresis. | the nature of replication origins in eukaryotic chromosomes has been examined in some detail only in yeast, drosophila, and mammalian cells. we have used highly synchronous cultures of plasmodia of the myxomycete physarum and two-dimensional agarose gel electrophoresis to examine replication of two developmentally controlled, early replicated genes over time in s-phase. a single, discrete origin of replication was found within 4.8 kb of the lav1-5 gene, which encodes a homolog of profilin. in co ... | 1993 | 7902230 |
| identification, partial sequence and genetic analysis of mlpa, a novel gene encoding a myosin-related protein in physarum polycephalum. | studies of motility in physarum polycephalum have concentrated on the well-defined actomyosin system in plasmodia. it is clear from recent genetic studies in lower eukaryotes that myosin is involved in a number of physiological processes in addition to the contractile functions previously ascribed to the classical type ii myosins. moreover, the myosin protein family has proved to be more complex than anticipated, with an increasing number of reported specialized isoforms. although a myosin type ... | 1994 | 7916270 |
| complex terminal structure of a linear mitochondrial plasmid from physarum polycephalum: three terminal inverted repeats and an orf encoding dna polymerase. | the mitochondria of physarum polycephalum have a linear plasmid (mf) which promotes mitochondrial fusion. to determine the terminal structure of the mf plasmid, restriction fragments derived from its ends were cloned and sequenced. the sequences showed that the mf plasmid has three kinds of terminal inverted repeats (tirs). the most characteristic feature is a 144-bp repeating unit which exists between a 205-bp tir at the extreme ends of the plasmid and another 591-bp tir. all of the clones show ... | 1994 | 7923412 |
| crocacin, a new electron transport inhibitor from chondromyces crocatus (myxobacteria). production, isolation, physico-chemical and biological properties. | crocacin was isolated from the biomass of the myxobacterium chondromyces crocatus, strain cm c3. it inhibited the growth of a few gram-positive bacteria and a wide spectrum of yeasts and molds. in beef heart submitochondrial particles, crocacin blocked the electron transport within the bc1-segment (complex iii) and caused a red shift in the reduced spectrum of cytochrome b with a maximum at 569 nm. | 1994 | 7928674 |
| requirements for self-splicing of a group i intron from physarum polycephalum. | the third intron from physarum polycephalum (pp lsu 3) is one of the closest known relatives to the well-studied tetrahymena group i intron. both introns are located at the same position in the 26s rrna gene, and with the exception of an open reading frame in pp lsu 3, are highly homologous. while pp lsu 3 has been shown to self splice, little is known about its activity in vitro. we have examined the requirements for self splicing in greater detail. despite its similarity to the tetrahymena int ... | 1994 | 7937160 |
| dinucleoside oligophosphates in micro-organisms. | | 1994 | 7942317 |
| microtubules are required in amoeba chemotaxis for preferential stabilization of appropriate pseudopods. | amoebae of physarum polycephalum exhibit chemotactic responses to glucose and to camp. the chemotaxing amoebae exhibit alternating locomotive movements: relatively linear locomotion and movements that change the direction of the locomotion. such locomotive activity is tightly coupled with the changes in the number and the positions of the pseudopods; cells have one pseudopod at the leading edge during their linear locomotion, while they have multiple pseudopods when they are changing the directi ... | 1994 | 7983169 |
| nucleolar introns from physarum flavicomum contain insertion elements that may explain how mobile group i introns gained their open reading frames. | comparison of two group i intron sequences in the nucleolar genome of the myxomycete physarum flavicomum to their homologs in the closely related physarum polycephalum revealed insertion-like elements. one of the insertion-like elements consists of two repetitive sequence motifs of 11 and 101 bp in five and three copies, respectively. the smaller motif, which flanks the larger, resembles a target duplication and indicates a relationship to transposons or retroelements. the insertion-like element ... | 1994 | 7984404 |
| subcellular location of enzymes involved in core histone acetylation. | multiple enzyme forms of histone deacetylase and histone acetyltransferase exist in germinating maize embryos. we analyzed the association of the different enzymes to chromatin by ion exchange chromatography of subcellular fractions from different time points of embryo germination. the vast majority of histone deacetylase hd-1a was not bound to chromatin, since it was solubilized during chromatin isolation, regardless of its phosphorylation state and the phase of embryo germination. in contrast, ... | 1994 | 7993915 |
| dna methylation during differentiation of a lower eukaryote, physarum polycephalum. | starvation-induced differentiation of the slime mould physarum polycephalum is accompanied by continuous methylation of dna. no stable changes in the overall level of dna methylation are evident, but a gene known to be transcribed specifically during differentiation is subject to increased methylation. inhibitors of dna methylation preclude differentiation of p. polycephalum, although they are only marginally inhibitory to normal growth. taken together these results indicate that methylation of ... | 1994 | 7998920 |
| gene-specific changes of dna methylation accompany differentiation of the slime mold physarum polycephalum. | | 1994 | 8000365 |
| a luciferase expression system for physarum that facilitates analysis of regulatory elements. | we have developed a transient expression system for the protist physarum polycephalum based on firefly luciferase. we demonstrate the utility of this system for comparing the activities of different promoters in physarum amoebae, and also for detecting genetic elements that affect the level of gene expression. this system is likely to facilitate improvements in the stable transformation of this organism. | 1994 | 8001165 |
| surface changes during growth and development of slime molds. | | 1994 | 8047011 |
| time-resolved detection of three intracellular signals controlling photomorphogenesis in physarum polycephalum. | incompetent plasmodia of physarum polycephalum exposed to a light pulse sporulated after reaching the competent stage. fusion of irradiated plasmodia with dark-incubated plasmodia and analysis of sporulation indicated the presence of a morphogenetic signal. it is concluded that a logic and gate integrates the photoreceptor signal and the competence signal and controls the formation of the morphogenetic signal. | 1994 | 8071235 |
| [immunochemical identification of kinesin in physarum polycephalum]. | physarum polycephalum, a low eukaryote ameba provides an attractive system for studying contractile proteins. in this work, we have identified a kinesin-like protein in the plasmodium of physarum polycephalum by western blotting, using monoclonal antibody against kinesin (bovine brain). the molecular weight of the polypeptide which immunologically cross-reacts with kinesin from bovine brain is about 137kd. it suggests that the 137kd polypeptide is the heavy chain of the kinesin in physarum polyc ... | 1994 | 8073764 |
| two alleles of a developmentally regulated alpha-tubulin locus in physarum polycephalum replicate on different schedules. | the replication timing of a pair of natural alleles was compared at two alpha-tubulin loci of the physarum plasmodium. taking advantage of the naturally synchronous cell cycle of nuclei within the syncytial plasmodium, we analyzed the replication schedule of specific dna fragments to a resolution of 10-min intervals within a 3-h s phase. at this level of resolution, differences in replication timing between polymorphic alleles at the same locus can be detected in a heterozygote. specifically, th ... | 1993 | 8093328 |
| modulation of dna synthesis by microtubule-associated protein 2 in the nuclear matrix isolated from physarum polycephalum. | the mechanism of stimulation of dna synthesis by microtubule-associated protein 2 (map2) was examined in the nuclear matrix isolated from physarum polycephalum. porcine brain map2 stimulated dna synthesis by the matrix with exogenous templates, but not with endogenous templates. kinetic analyses showed that map2 decreases the km of the matrix for deoxyribonucleoside triphosphates. comparison of the km values of active- and latent-type dna replication machineries of physarum suggested a possible ... | 1993 | 8136708 |
| physarum vitronectin-like protein has extensive homology to dihydrolipoamide acetyltransferase. | physarum vitronectin-like protein with a molecular mass of 70 kda cross-reacts with anti-bovine vitronectin and promotes cell-spreading (miyazaki, k. et al. 1992. exp. cell res., 199: 106-110.). the amino-terminal sequence of physarum vitronectin-like protein is, however, distinct from those of animal vitronectins but shows significant sequence homology with dihydrolipoamide acetyltransferase, a component of pyruvate dehydrogenase complex. we have investigated the structural relationships betwee ... | 1993 | 8168157 |
| inhibition of cell proliferation by a unique lysophosphatidic acid, phylpa, isolated from physarum polycephalum: signaling events of antiproliferative action by phylpa. | the unique physarum lysophosphatidic acid, phylpa, having a cyclopropane in the fatty acid moiety and a cyclic phosphate at c-2 and c-3 positions of the glycerol, inhibited proliferation of human fibroblast cells, tig-3 and tig-7, which were cultured in a chemically defined (serum-free) medium. the cells at s- and m-phases proceeded to g2- and g1-phases, respectively, and most of cells were arrested at g1- or g2-phase during phylpa treatment. the growth was recovered when phylpa was removed from ... | 1993 | 8168160 |
| changes in phospholipids during the cell cycle of myxomycete physarum polycephalum. | the rate of 32pi incorporation into the main membrane phospholipid fractions, i.e. phosphatidylcholine (pc), phosphatidylethanolamine (pe) and phosphatidylinositol (pi), as well as their contents in the cells during synchronous growth of the myxomycete, physarum polycephalum, have been studied. it has been found that both the phospholipid levels and the rates of 32pi incorporation increase during the s phase till the early g2 phase, remain nearly constant during the g2 phase and fall to the init ... | 1994 | 8181562 |
| molecular and cellular mechanisms of mitochondrial nuclear division and mitochondriokinesis. | our present understanding of mitochondrial division can be summarized as follows: mitochondria contain a specific genome, synthesize their own dna, and multiply semi-autonomously. strands of mitochondrial dna (mt-dna) in the in vivo organelles of all eukaryotes are organized to form mitochondrial nuclei (nucleoids) (mt-nuclei) with specific proteins including a histone-like protein and transcription factors at the central region of the mitochondrion. we can easily observe the mt-nucleus in vivo ... | 1994 | 8204912 |
| a highly conserved repetitive sequence from physarum polycephalum contains nucleotide arrangements similar to replicator sequences. | an interspersed repetitive sequence from physarum polycephalum has been cloned and analysed. the 394 bp sequence is highly conserved and contains several homopolymeric (da)-(dt) tracts capable of forming bent dna structures and a 10/11 match to the yeast-ars-consensus sequence. the repetition frequency of the described sequence is about 3000 to 7000, a number that would fit with the distribution of replicator segments in physarum. | 1993 | 8218403 |
| identification of proteins immunologically related to vertebrate lamins in the nuclear matrix of the myxomycete physarum polycephalum. | lamin-like proteins have been identified as components of the nuclear matrix of the myxomycete physarum polycephalum. a 67 kda homologue was detected by immunoblotting of nuclear matrix proteins with affinity-purified anti-lamin antibodies of human autoimmune sera. a 65 kda lamin b homologue was identified with polyclonal antibodies against turkey erythrocyte lamin b in nuclei and nuclear matrix of physarum amoebae and plasmodia. indirect immunofluorescence microscopy revealed that the 65 and 67 ... | 1993 | 8223702 |
| stable, selectable, integrative dna transformation in physarum. | the physarum polycephalum actin promoter, pardc, can drive transient expression of heterologous genes in physarum amoebae. the hph gene, encoding hygromycin (hy) phosphotransferase, can confer resistance to hy on a broad spectrum of organisms. when pardc is translationally fused to hph and transformed into yeasts on high-copy-number vectors, the yeasts become hy resistant (hyr), showing that pardc-hph is a functional, selectable genetic element. to establish a stable transformation system for ph ... | 1993 | 8224865 |
| isolation of a new species of physarum lysophosphatidic acid, phylpa, and its effect on dna polymerase activity. | a new species of lysophosphatidic acid was isolated from myxoamoebae of a true slime mold, physarum polycephalum, and structural studies were performed. the purified substance was subjected to nuclear magnetic resonance spectroscopy (nmr), infrared spectroscopy (ir), fast atom bombardment mass spectroscopy (fab/ms), alkaline hydrolysis and tandem mass spectroscopy (ms/ms), and the results suggested this substance to be lysophosphatidic acid composed of a cyclic phosphate and cis-11,12-methylene ... | 1993 | 8242792 |
| substitutional and insertional rna editing of the cytochrome c oxidase subunit 1 mrna of physarum polycephalum. | the term rna editing encompasses two types of specific alterations in the coding potential of rna molecules: base substitution and the insertion (or deletion) of nucleotides. such changes in rna sequence can have profound effects on gene expression, and, indeed, most genes in the mitochondria of plants, trypanosomatids, and physarum appear to require editing for their expression. we describe here the first instance of the utilization of both types of rna editing in the processing of a single mrn ... | 1993 | 8244983 |
| interaction of the intron-encoded mobility endonuclease i-ppoi with its target site. | endonucleases encoded by mobile group i introns are highly specific dnases that induce a double-strand break near the site to which the intron moves. i-ppoi from the acellular slime mold physarum polycephalum mediates the mobility of intron 3 (pp lsu 3) in the extrachromosomal nuclear ribosomal dna of this organism. we showed previously that cleavage by i-ppoi creates a four-base staggered cut near the point of intron insertion. we have now characterized several further properties of the endonuc ... | 1993 | 8246971 |
| editing of the mitochondrial small subunit rrna in physarum polycephalum. | post-transcriptional insertion, substitution or deletion of nucleotides in rna (rna editing) has been observed in rnas from a number of organisms but always in messenger rna or transfer rna. we report here that the 17s rrna of the mitochondrial ribosome of physarum polycephalum is edited at 40 sites with single cytidine insertions. the locations of the editing sites are fairly evenly distributed throughout the rna and do not correspond to any obvious feature of the primary sequence or secondary ... | 1994 | 8306965 |
| patterns of inheritance, development and the mitotic cycle in the protist physarum polycephalum. | | 1993 | 8310878 |
| identification of a ras gene in the slime mold physarum polycephalum. | a ras homologue was identified in the cdna library from the slime mold physarum polycephalum. the cdna codes for a protein of 189 amino acids, showing high homology to ras genes from other organisms, especially to these from dictyostelium discoideum. amino acid sequence at the c-terminus of the putative protein suggests that unlike most other ras proteins, it is not palmitoylated and bears a geranylgeranyl rather than farnesyl chain. | 1993 | 8318547 |
| [regulation of cell proliferation by lysophosphatidic acid]. | | 1993 | 8337407 |
| information propagation by spatio-temporal pattern change of ca2+ concentration throughout physarum polycephalum with repulsive stimulation. | the development of a spatio-temporal pattern of ca2+ concentration (ca2+ pattern) in the plasmodium of physarum polycephalum during repulsive response was studied using fura-2. in the migrating cell, the gradient of the ca2+ concentration (ca2+ gradient) immediately showed a decrease in local concentration in the area (s-site) stimulated by 50 mm kcl. the concentration rose and then decreased in a site neighboring the s-site. this transient increase of ca2+ concentration, the duration of which w ... | 1993 | 8364978 |
| nucleotide and predicted amino acid sequence of a new member of the ras gene family from the slime mold physarum polycephalum. | a second ras homologue, designated ppras2, has been isolated from physarum polycephalum mixed amoebae and flagellates cdna library. ppras2 encodes a protein of 193 amino acids of a calculated m(r) of 21,633. the deduced amino acid sequence is highly homologous to ppras1 and other ras genes from slime molds. the amino acid sequence at the c-terminus of the putative protein suggests that like other slime mold ras proteins but not the ones from other organisms, it is modified by geranylgeranylation ... | 1993 | 8373809 |
| mitotic segregation of the nucleolar ribosomal rna in physarum polycephalum. | in the naturally synchronous mitosis of the syncytial plasmodium of physarum polycephalum, the nucleolus disintegrates in prophase, releasing a large amount of ribosomal rna. using biotinylated rdna probes, we studied by high-resolution in situ hybridization the behavior of this nucleolar rna throughout mitosis. our results demonstrate that this rrna is stable and maintained within the mitotic nucleus mainly, but not exclusively, associated with fibrillar nucleolar remnants. the distribution of ... | 1993 | 8375480 |
| a mobile group i intron from physarum polycephalum can insert itself and induce point mutations in the nuclear ribosomal dna of saccharomyces cerevisiae. | pp lsu3 is a mobile group i intron in the extrachromosomal nuclear ribosomal dna (rdna) of physarum polycephalum. as found for other mobile introns, pp lsu3 encodes a site-specific endonuclease, i-ppo, which mediates "homing" to unoccupied target sites in physarum rdna. the recognition sequence for this enzyme is conserved in all eucaryotic nuclear rdnas. we have introduced this intron into a heterologous species, saccharomyces cerevisiae, in which nuclear group i introns have not been detected. ... | 1993 | 8380887 |
| purification and partial amino acid sequence of the actin-fragmin kinase from physarum polycephalum. | the 80-kda actin-fragmin kinase (afk) was purified from physarum polycephalum microplasmodia to apparent homogeneity through a procedure involving six chromatographic steps. taking the activity at the first purification step as 100%, the kinase was purified more than 1500-fold, with an overall yield of 8%. the specific activity of the purified enzyme was 700 u/mg. the total amount of afk present could be estimated as 34 ng/mg extracted protein. one of the polyclonal antibodies raised against fou ... | 1993 | 8389700 |
| a genetic system controlling mitochondrial fusion in the slime mould, physarum polycephalum. | we have identified two distinct mitochondrial phenotypes, namely, mif+ (mitochondrial fusion) and mif- (mitochondrial fusion-deficient), and have studied the genetic system that controls mitochondrial fusion in the slime mould, physarum polycephalum. a mitochondrial plasmid of approximately 16 kbp was identified in all mif+ plasmodial strains. this plasmid is apparently responsible for promoting mitochondrial fusion, and it is inserted into the mitochondrial dna (mtdna) in successive sexual cros ... | 1993 | 8436271 |
| fine structure observations of phagotrophic activity by plasmodia of physarum polycephalum. | scanning electron microscopic observations of feeding plasmodia show three characteristic features: 1) extension of multilobed pseudopodia protruding from the leading edge of the plasmodium as it advances onto the surface of a food particle, 2) confluence of the lobes to form a sheath-like pseudopodium attached to the surface of the food particle, and 3) protrusion of small nodules with thin lamellar projections from the leading edge of the plasmodium. sections through freeze-dried preparations ... | 1993 | 8457802 |
| high resolution polyacrylamide gel electrophoresis of physarum polycephalum histones: improved resolution of variants and modified forms. | an electrophoresis system providing a good resolution of all basic proteins and their variants or modified forms extracted from physarum polycephalum nuclei was developed. this two-dimensional polyacrylamide gel electrophoresis system combines the use of an aut gel containing a preformed gradient of urea in the first dimension and a sds polyacrylamide gel in the second one. | 1993 | 8470794 |
| research note: differential chemotaxis of physarum polycephalum to salmonella gallinarum and salmonella pullorum. | the chemotactic and chemotropic responses of the plasmodial stage of the slime mold physarum polycephalum were used to distinguish salmonella gallinarum and salmonella pullorum from 10 salmonella serovars that are commonly isolated from domestic poultry. utilizing an in vitro plasmodium agar plate assay method, p. polycephalum was attracted to s. gallinarum and s. pullorum, but the organism was repelled by salmonella derby, salmonella dublin, salmonella enteritidis, salmonella heidelberg, salmon ... | 1993 | 8479960 |
| two developmentally regulated mrnas encoding actin-binding proteins in physarum polycephalum. | a cdna library from amoebae of physarum polycephalum was screened by differential hybridization. two clones contained inserts for mrnas present in amoebae and absent in plasmodia. the lav3-4 cdna encodes a 402 aa protein (abp-46) that shows sequence similarity to the actin binding site in the n-terminal region of the alpha-actinin family. the lav3-5 cdna is 76% identical to the dictyostelium actin bundling protein, which cross-links and stabilizes actin filaments in amoebal filopodia. | 1993 | 8485148 |
| reduction of uv-induced mitotic delay by caffeine in budr-substituted plasmodia of physarum polycephalum. | chromosomal dna of the synchronously mitotic plasmodia of p. polycephalum was substituted with 5-bromo-2'-deoxyuridine, by growing the plasmodia during s phase, on a medium containing this nucleoside analog. a strong synergism was observed between bromodeoxyuridine and uv-irradiation, in late g2-irradiated plasmodia in that, the mitotic delay obtained in them was much more than a simple sum of the delays induced by these two agents individually. it was also observed that the mitotic delay in thi ... | 1993 | 8500824 |
| purification, some properties, and primary structure of base non-specific ribonucleases from physarum polycephalum. | two ribonucleases (rnase phya and rnase phyb) were purified to homogeneity on sds-page from the culture filtrate of the fungus physarum polycephalum. the apparent molecular weights of rnases phya and phyb were about 20,000. the ph optima of these two rnases were around 4.5-4.75. the rnases released mononucleotides from rna in the order of 3'-gmp, 3'-amp, and 3'-pyrimidine nucleotides. rnase phya and rnase phyb have the n-terminal amino acid sequences stsfd--- and kstsf--, respectively. this find ... | 1993 | 8514732 |
| inhibition of maize histone deacetylases by hc toxin, the host-selective toxin of cochliobolus carbonum. | hc toxin, the host-selective toxin of the maize pathogen cochliobolus carbonum, inhibited maize histone deacetylase (hd) at 2 microm. chlamydocin, a related cyclic tetrapeptide, also inhibited hd activity. the toxins did not affect histone acetyltransferases. after partial purification of histone deacetylases hd1-a, hd1-b, and hd2 from germinating maize embryos, we demonstrated that the different enzymes were similarly inhibited by the toxins. inhibitory activities were reversibly eliminated by ... | 1995 | 8535144 |
| a novel intracellular acid proteinase from the plasmodia of a true slime mold, physarum polycephalum. | | 1995 | 8540373 |
| substrate binding and turnover by the highly specific i-ppoi endonuclease. | intron-encoded endonucleases are distinguished by their ability to catalyze the cleavage of double-stranded dna with high specificity. i-ppoi endonuclease, an intron-encoded endonuclease from the slime mold physarum polycephalum, is a small enzyme (2 x 20 kda) that catalyzes the cleavage of a large asymmetric dna sequence (15 base pairs). here, the interactions of i-ppoi with its substrate were examined during both binding (in the absence of mg2+) and catalysis (in the presence of mg2+). using c ... | 1996 | 8547243 |
| the two alleles of the happ gene in physarum polycephalum code for different proteins. | many mrnas show cell-type specific expression in the acellular slime mold physarum polycephalum. the most abundant plasmodial-specific mrna (happ) encodes a small hydrophobic protein of 187 amino acids that contains a potential signal peptide. southern hybridizations using the happ cdna showed that the happ gene is a single copy gene with two alleles, happ1 and happ2. the alleles have restriction enzyme polymorphisms. the nucleotide sequence of the coding region of the happ1 allele was obtained ... | 1995 | 8547312 |
| nuclear matrix and the cell cycle. | the facts that the nuclear matrix represents a structural framework of the cell nucleus and that nuclear events, such as dna replication, transcription, and dna repair, are associated with this skeletal structure suggest that its components are subject to cell cycle-regulatory mechanisms. cell cycle regulation has been shown for nuclear lamina assembly and disassembly during mitosis and chromatin reorganization. little attention has so far been paid to internal nuclear matrix proteins and matrix ... | 1995 | 8557492 |
| chondramides a approximately d, new antifungal and cytostatic depsipeptides from chondromyces crocatus (myxobacteria). production, physico-chemical and biological properties. | novel depsipeptides, named chondramides were produced at levels up to 4.3 mg/liter by several myxobacteria of the genus chondromyces. the compounds are structurally closely related to jaspamide/jasplakinolide from marine sponges of the genus jaspis. initially the chondramides were detected in acetone extracts of the biomass of chondromyces crocatus, strain cm c2. so far, four structural variants could be characterized, the chondramides a approximately d. they inhibited the growth of a few yeasts ... | 1995 | 8557566 |
| functional mapping of the branched signal transduction pathway that controls sporulation in physarum polycephalum. | sporulation of starving plasmodia of physarum polycephalum was found to be induced by far-red light, blue light or heat shock, each of which is perceived by a different input receptor system. the branched signal transduction pathway was mapped and the time-dependent formation of some of its components analyzed. | 1995 | 8570734 |
| "candidatus comitans," a bacterium living in coculture with chondromyces crocatus (myxobacteria). | we describe the phylogenetic position and some taxonomically relevant characteristics of a small pleomorphic gram-negative bacterium that was cocultured with some strains of the myxobacterium chondromyces crocatus that were isolated from the same geographic and ecological habitat. a 16s ribosomal dna analysis revealed that the companion was a member of the "cytophaga-flavobacterium-bacteroides" complex and was most closely related to members of the genus sphingobacterium. the results of a fatty ... | 1996 | 8573486 |
| dna polymerase delta of physarum polycephalum. | dna polymerase delta from the phylogenetically ancient slime mold physarum polycephalum has been 380-fold enriched from amoebae. it was found to have the properties typical for this type of dna polymerase from higher eukaryotes with regard to effectors, template-primer acceptance, co-purification with 3'-5'-exonuclease activity, as well as the effect of endogenous proliferating cell nuclear antigen (pcna) from amoebae on the stimulation and processivity of dna synthesis. an identified cdna fragm ... | 1995 | 8593684 |
| rearrangements of mitochondrial dna and the mitochondrial fusion-promoting plasmid (mf) are associated with defective mitochondrial fusion in physarum polycephalum. | a specific linear mitochondrial plasmid (mf) is genetically associated with the fusion of mitochondria in the true slime mould, physarum polycephalum. in matings between mf+ and mf- strains, which respectively carry and do not carry the mf plasmid, mitochondrial fusion occurs in the zygote. mitochondrial fusion induces recombination between specific sites in the mitochondrial dna (mtdna) and in the mf plasmid. to detect a region which is associated with the mitochondrial fusion in the mf plasmid ... | 1996 | 8595672 |
| identification and sequence analysis of a rap gene from the true slime mold physarum polycephalum. | a member of the ras gene superfamily, belonging to the rap family and designated pprap1, was isolated from a cdna library from the true slime mold physarum polycephalum by plaque hybridization in combination with 5'-race. the assembled nucleotide sequence of pprap1 (1062 bp) has an open reading frame coding for a protein of 188 amino acids of a calculated m(r) of 21035. this protein exhibits: (i) a highly conserved gtp binding domain containing a putative effector domain, with the threonine-for- ... | 1996 | 8605245 |
| fragmin, a microfilament regulatory protein from physarum polycephalum, is phosphorylated by casein kinase ii-type enzymes. | fragmin is a 42 kda regulatory protein involved in actin microfilament organization in physarum polycephalum. we show that fragmin is a target of casein kinase ii (ck ii) enzymes isolated from evolutionarily divergent species. in physarum microplasmodia, two such kinases were identified. a serine residue located in the sequence gly-gly-ser-asp-leu-glu constitutes the phosphorylation site and was identified by phosphopeptide sequencing, mass spectometry analysis, and inhibition studies with a syn ... | 1996 | 8611538 |
| is the function of the cdc2 kinase subunit proteins tuned by their propensities to oligomerize? conformational states in solution of the cdc2 kinase partners p13suc1 and p9cksphy. | the cdc2 kinase subunit (cks) proteins play an essential function in the control of mitosis through their molecular complexes with the cdc2 kinase. in this work, we characterize the conformational state(s) in solution of the cks proteins p13suc1 from schizosaccharomyces pombe and p9cksphy from physarum polycephalum. monomers of p13suc1 and p9cksphy were found to be markedly nonglobular, presumably with a long, nonfolded c-terminal moiety. this was in contrast to the previously published structur ... | 1996 | 8611549 |
| mapping of a replication origin within the promoter region of two unlinked, abundantly transcribed actin genes of physarum polycephalum. | we analyzed the replication of two unlinked actin genes, ardb and ardc , which are abundantly transcribed in the naturally synchronous plasmodium of the slime mold physarum polycephalum. detection and size measurements of single-stranded nascent replication intermediates (ris) demonstrate that these two genes are concomitantly replicated at the onset of the 3-h s phase and tightly linked to replication origins. appearance of ris on neutral-neutral two-dimensional gels at specific time points in ... | 1996 | 8622700 |
| cloning and genomic sequence of the physarum polycephalum ppras1 gene, a homologue of the ras protooncogene. | we have cloned the genomic copy of the ppras1 gene, a homologue of the ras proto-oncogene, from the true slime mold physarum polycephalum. ppras1 contains five small introns, four of which have a high content of pyrimidines. the (dc)-homopolymers present in introns 4 and 5 may be responsible for the observed reca-independent deletion in ppras1 upon amplification of the ppras1-bearing plasmid by choramphenicol. although ppras1 exhibits amino acid and nucleotide homologies with the ddrasg gene, a ... | 1996 | 8635743 |
| xenopus oocytes express multiple receptors for lpa-like lipid mediators. | in xenopus laevis oocytes, both lysophosphatidic acid (lpa) and a cyclic phosphate-containing analogue 1-acyl-sn-glycero-2,3-cyclic phosphate (clpa) isolated from physarum polycephalum activated oscillatory cl- currents. clpa elicited oscillatory currents only when applied extracellularly and, similarly to lpa, evoked homologous desensitization. clpa applied to oocytes previously desensitized b y lpa failed to elicit a current, indicating that lpa completely desensitized the clpa receptors. in c ... | 1996 | 8638656 |
| in vivo topoisomerase ii cleavage sites in the ribosomal dna of physarum polycephalum. | we have analyzed the topoisomerase ii cleavage sites in the extrachromosomal ribosomal dna of the lower eukaryote physarum polycephalum using the topoisomerase ii-specific inhibitor, 6,8-difluoro-7-(4-hydroxyphenyl)-1-cyclopropyl-4-quinolone-3-carboxylic acid. most of the in vivo topoisomerase ii cleavage sites were found either in the transcribed region of ribosomal dna or in the palindromic region surrounded by the replication origins. two classes of sites were identified: those which correlat ... | 1996 | 8639539 |
| purification and some properties of hemagglutinin from the myxomycete, physarum polycephalum. | a new hemagglutinin was isolated from the plasmodium of physarum polycephalum by salting out with ammonium sulphate followed by chromatography on de-32, deae-toyopearl and hydroxyapatite. this hemagglutinin, named physarumin, was purified 1000-fold over crude extracts. the molecular weight of physarumin was determined to be 22,000 by size exclusion chromatography on bio-gel p-60 and 8,700 by sds-polyacrylamide gel electrophoresis. physarumin agglutinated rabbit, guinea pig, horse and human eryth ... | 1996 | 8698086 |
| phase switching of oscillatory contraction in relation to the regulation of amoeboid behavior by the plasmodium of physarum polycephalum. | the plasmodium of the true slime mould physarum polycephalum is a large aggregate of protoplasm and behaves like an amoeboid cell, exhibiting rhythmic contraction everywhere within the organism. phase dynamics of these oscillations were studied in relation to the global organization of amoeboid behavior, by analysing the thickness oscillation, isotonic tension and the motive force of the streaming. usually the plasmodium showed synchrony, the phase of the oscillation being the same everywhere ex ... | 1996 | 8762336 |
| a comparative study of histone deacetylases of plant, fungal and vertebrate cells. | the enzymatic equilibrium of reversible core histone acetylation is maintained by two enzyme activities, histone acetyltransferase and histone deacetylase (hd). these enzyme activities exist as multiple enzyme forms. the present report describes methods to extract different hd-forms from three organisms, germinating maize embryos, the myxomycete physarum polycephalum, and chicken red blood cells; it provides data on the chromatographic separation and partial purification of hd-forms. in germinat ... | 1996 | 8814225 |
| nuclear accumulation and homeostasis of the unusual polymer beta-poly (l-malate) in plasmodia of physarum polycephalum. | the plasmodium of physarum polycephalum specifically contains an unusual polyester, beta-poly(l-malate), which is not found in any of the mononucleate forms of its life cycle. plasmodia growing on d-glucose have been analyzed for beta-poly(l-malate) in nuclei, cytosol and culture medium after cell fractionation, purification by chromatography on deae-cellulose and digestion of proteins/nucleic acids. nuclei contained 400 micrograms polymer per 1 g of plasmodia, corresponding to a nuclear concent ... | 1996 | 8864666 |
| a novel type of protein kinase phosphorylates actin in the actin-fragmin complex. | actin-fragmin kinase (afk) from physarum polycephalum specifically phosphorylates actin in the egta-resistant 1:1 actin-fragmin complex. the cdna deduced amino acid sequence reveals two major domains of approximately 35 kda each that are separated by a hinge-like proline/serine-rich segment of 50 residues. whereas the n-terminal domain does not show any significant similarity to protein sequences from databases, there are six complete kelch repeats in the protein that comprise almost the entire ... | 1996 | 8896448 |
| a unique u5-->a substitution in the physarum polycephalum u1 snrna: evidence at the rna and gene levels. | the 5' terminal sequence of u1 snrna that base-pairs with the intron 5' splice site in the course of spliceosome assembly was considered to be universally conserved. a study of the p polycephalum u1 snrna at both rna and gene levels shows that there are exceptions to this rule: the p polycephalum u1 snrna has a u to a substitution at position 5, that is partially compensated by a high frequency of t residue at position +4 of introns. in contrast to the yeast genome, the p polycephalum genome con ... | 1996 | 8915532 |
| a single gamma-tubulin gene and mrna, but two gamma-tubulin polypeptides differing by their binding to the spindle pole organizing centres. | cells of eukaryotic organisms exhibit microtubules with various functions during the different developmental stages. the identification of multiple forms of alpha- and beta-tubulins had raised the question of their possible physiological roles. in the myxomycete physarum polycephalum a complex polymorphism for alpha- and beta-tubulins has been correlated with a specific developmental expression pattern. here, we have investigated the potential heterogeneity of gamma-tubulin in this organism. a s ... | 1996 | 8923209 |
| action spectrum for sporulation and photoavoidance in the plasmodium of physarum polycephalum, as modified differentially by temperature and starvation. | the plasmodium of the myxomycete physarum polycephalum sporulates in bright natural environments, suggesting a relationship between photobehavior and sporulation. thus, the action spectra for two light-dependent phenomena as well as the effects of other environmental conditions have been studied. sporulation like photo-avoidance responded to uvc (near 270 nm) and near ir (near 750 nm) in addition to the well-documented uva (near 350 nm) and blue (near 460 nm) regions. sporulation and photoavoida ... | 1996 | 8931386 |
| in vivo phosphorylation of actin in physarum polycephalum. study of the substrate specificity of the actin-fragmin kinase. | actin-fragmin is a heterodimeric protein complex from physarum polycephalum microplasmodia that is phosphorylated in vitro at residues thr203 and thr202 of the actin subunit by the endogenous actin-fragmin kinase. following phosphorylation, the f-actin capping activity of the complex becomes ca(2+)-dependent, suggesting a fundamental regulatory role in controlling f-actin growth [gettemans, j., de ville, y., waelkens e. and vandekerckhove, j. (1995) j. biol. chem. 270, 2644-2651]. in this study ... | 1996 | 8944781 |
| localization of the newly initiated and processed ribosomal primary transcripts during the mitotic cycle in physarum polycephalum. | we analyzed the fate of the rrna released as a result of the prophasic disintegration of the nucleolus, during the "closed" mitosis of the naturally synchronous plasmodium of physarum polycephalum. using a probe complementary to the mature 19s and 26s rrna, we previously showed that the nucleolus-derived rrnas are stable in mitosis, mainly associated with numerous fibrillar nucleolar remnants (pierron and puvion-dutilleul, 1993, exp. cell res. 208, 509-517). however, a significant fraction of th ... | 1996 | 8986624 |
| heat stress induces a glycosylation of membrane sterol in myxoamoebae of a true slime mold, physarum polycephalum. | to know the very early events occurring after heat shock, the changes of membrane lipids were examined. heat stress induced the production of a certain glycolipid in the myxoamoebae of physarum polycephalum in a few minutes. the purified glycolipid was determined to be a poriferasterol monoglucoside by structural studies that was previously reported to be expressed during the differentiation of physarum cells from haploid myxoamoebae to diploid plasmodia (murakami-murofushi, k., nakamura, k., oh ... | 1997 | 8995287 |
| phosphatidylinositol 4,5-bisphosphate specifically stimulates pp60(c-src) catalyzed phosphorylation of gelsolin and related actin-binding proteins. | gelsolin is a widely distributed ca2+-dependent regulator of the cortical actin network. we demonstrate that gelsolin is phosphorylated by pp60(c-src) and that this phosphorylation is dramatically enhanced by phosphatidylinositol 4,5-bisphosphate (pip2), known to specifically interact with gelsolin. other phospholipids display only a marginal effect. pp56(lck), a tyrosine kinase of the same family, does not phosphorylate gelsolin. other mammalian actin-binding proteins such as profilin and capg ... | 1997 | 9013885 |
| molecular evidence for association between the sphingobacterium-like organism "candidatus comitans" and the myxobacterium chondromyces crocatus. | seven strains of the myxobacterium chondromyces crocatus, isolated from widely separated geographic regions, were investigated for the presence of an associate gram-negative, rod-shaped companion bacterium that is phylogenetically related to the genus sphingobacterium and has been named "candidatus comitans" (c. a. jacobi, e. stackebrandt, h. reichenbach, and b. j. tindall, int. j. syst. bacteriol. 46:119-122, 1996). five of the chondromyces strains were found to be associated with a companion b ... | 1997 | 9023949 |
| activation of a ca(2+)-dependent protein kinase in response in heat shock in the myxoamoebae of a true slime mold, physarum polycephalum. | protein kinase activities in myxoamoebae of a true slime mold, physarum polycephalum, were investigated in response to heat shock. in-gel assay detected an apparent activation of a ca(2+)-dependent, 53-kda protein kinase that phosphorylated casein but not histone h1. this enzyme needed co-presence of mg2+ ion with ca2+ for activity. treatment with calf intestinal alkaline phosphatase did not affect the heat-inducible 53-kda protein kinase activity at all. the effects of protein kinase inhibitors ... | 1996 | 9078411 |
| oncogene- and tumor-suppressor gene-related proteins in plants and fungi. | protooncogene- and tumor-suppressor gene proteins serve essential functions in the regulation of proliferation and differentiation of cells. abnormal regulation or mutation of these genes, or transformation with retroviral homologs, may lead to tumor development in animals. in contrast to vertebrates, only few data on these genes exist in plants and fungi. plant nuclear protooncogene homologs, such as myb and myc have multiple regulatory functions in metabolic pathways not existing in mammalian ... | 1996 | 9109497 |
| cell cycle-dependent activation of telomerase in naturally synchronized culture of a true slime mold, physarum polycephalum. | telomeres of physarum plasmodia did not shorten with numerous repeats of nuclear division, and an apparent activity of telomerase was detected in this organism. in naturally synchronized culture of physarum plasmodia, an evident activation of telomerase was observed at the late s-phase, just prior to the completion of in vivo dna replication, and the low telomerase activity was detected throughout the cell cycle. in the nuclei isolated from different phases of synchronized plasmodia, a higher ac ... | 1997 | 9125208 |
| no editing of mitochondrial plasmid transcripts in mitochondria of physarum that have an rna-editing system. | two types of rna editing have been reported in the mitochondria of physarum; extensive insertions of nucleotides and single-base substitutions. in the ng strain of p. polycephalum and its derivatives, mitochondria have a specific plasmid (mf) that promotes fusion of mitochondria. we examined the editing of transcripts derived from the mf plasmid. for analysis, we selected three regions of the plasmid, including a dna fragment that corresponded to missing conserved domains of the rna polymerase. ... | 1997 | 9179498 |
| molecular cloning, over-expression, developmental regulation and immunolocalization of fragminp, a gelsolin-related actin-binding protein from physarum polycephalum plasmodia. | fragminp is a ca2+-dependent actin-binding and microfilament regulatory protein of the gelsolin family. we screened a physarum polycephalum cdna library with polyclonal fragminp antibodies and isolated a cdna clone of 1,104 bp encoding 368 amino acids of fragminp, revealing two consensus phosphatidylinositol 4,5 bisphosphate-binding motifs in the central part of the protein. the first methionine is modified by an acetyl group, and three amino acids were missing from the protein coded for by the ... | 1997 | 9191045 |
| secretion of slime, the extracellular matrix of the plasmodium, as visualized with a fluorescent probe and its correlation with locomotion on the substratum. | slime, the extracellular matrix of physarum plasmodium, is secreted by the exocytosis of a vesicles that contain a slime precursor. using an antibody raised against biochemically purified slime, we detected the intracellular localization of the slime vesicle. slime vesicles are abundant in the advancing front of the plasmodium, as confirmed by electron microscopic observation in two different cross-sectional angles. screening various reagents, we found that rhodamine-phosphatidylethanolamine (rh ... | 1997 | 9195053 |
| nuclear translocation of constitutive heat shock protein 70 during s phase in synchronous macroplasmodia of physarum polycephalum. | the level of constitutive heat shock protein 70 (hsc70) in physarum polycephalum was analyzed by means of western blots during the synchronous cell cycle of macroplasmodia. total amounts as well as nuclear and cytoplasmic contents were determined separately and evaluated densitometrically. a drastic increase of nuclear hsc70 was observed 10-40 min after the initiation of s phase (600% of the m phase value) and thereafter a slow decline toward the next m phase. total hsc levels showed a slight (3 ... | 1997 | 9228774 |
| insertional editing in isolated physarum mitochondria is linked to rna synthesis. | the mitochondrial rnas of physarum polycephalum are edited efficiently by nucleotide insertion both in vivo and in isolated mitochondria. our recent studies have demonstrated that nucleotide addition can occur within 14-22 nt of the 3' end of a nascent rna, suggesting that insertional editing may be linked to transcription. to investigate the relationship between these processes, we have examined the effects of nucleotide concentration on templated and nontemplated nucleotide addition in isolate ... | 1997 | 9257642 |
| evolutionary relationships of the metazoan beta gamma-crystallins, including that from the marine sponge geodia cydonium. | beta gamma-crystallins are one major component of vertebrate lenses. here the isolation and characterization of a cdna, coding for the first beta gamma-crystallin molecule from an invertebrate species, the marine sponge geodia cydonium, is described. the size of the transcript as determined by northern blotting was 0.7 kb in length. the deduced amino acid sequence consists of 163 aa residues and comprises four repeated motifs which compose the two domains of the beta gamma-crystallin. motif 3 co ... | 1997 | 9263473 |
| ca2+-loaded spherulin 3a from physarum polycephalum adopts the prototype gamma-crystallin fold in aqueous solution. | spherulin 3a is the most abundantly expressed cytosolic protein in spherulating plasmodia of the slime mold physarum polycephalum. high yields of unlabeled, uniformly 15n and uniformly 13c/15n-labeled recombinant spherulin 3a from escherichia coli could be produced by a simple protocol described here. the three-dimensional solution structure of ca2+-loaded spherulin 3a was determined by homo- and heteronuclear nmr spectroscopy. the structure of monomeric spherulin 3a consists of two pleated beta ... | 1997 | 9281431 |
| histone acetyltransferases during the cell cycle and differentiation of physarum polycephalum. | the dynamic state of histone acetylation is maintained by histone acetyltransferases (hats) and deacetylases. cellular fractionation of plasmodia of physarum polycephalum and partial purification of subcellular fractions by chromatography revealed the existence of a cytoplasmic b-type and four nuclear a-type hats. the cytoplasmic b-enzyme was highly specific for histone h4, causing di-acetylation of h4 in vitro. the nuclear enzymes (hat-a1 to hat-a4) accepted all core histones as substrates, but ... | 1997 | 9309396 |
| ppras1ppras2 and pprap1 genes, members of a ras gene family from the true slime mold physarum polycephalum are developmentally regulated | the expression patterns of two true ras genes, ppras1 and ppras2and one rap gene, pprap1were examined in four physarum polycephalum developmental stages: uninucleate amoebae, plasmodia (multinucleate syncytia), spherules (a vegetative, dormant stage) and fruiting bodies. ppras1 and pprap1 are expressed in all stages examined with the maximum levels of their transcripts in amoebae and fruiting bodies, respectively, and the minimum levels in plasmodia, whereas the ppras2 transcript is only detecta ... | 1997 | 9344483 |
| g1-phase arrest is not a prerequisite for encystment in physarum. | amoebae of the myxomycete physarum polycephalum form resistant, walled cysts when the food bacteria in a culture have been consumed. no g1 phase has been detected in the vegetative amoebal cell cycle, most of which comprises the g2 phase. mature cysts are also in g2, but it has been reported that a g1 phase of roughly 24 h, followed by an s phase, is obligatory prior to encystment. we used flow cytometry to determine the distribution of dna contents in amoebal cultures at intervals during vegeta ... | 1997 | 9344617 |
| crystallization and preliminary x-ray studies of i-ppoi: a nuclear, intron-encoded homing endonuclease from physarum polycephalum. | the homing endonuclease i-ppoi is encoded by an optional third intron, pp lsu 3, found in nuclear, extrachromosomal copies of the physarum polycephalum 26s rrna gene. this endonuclease promotes the lateral transfer or "homing" of its encoding intron by recognizing and cleaving a partially symmetric, 15 bp homing site in 26s rdna alleles that lack the pp lsu 3 intron. the open reading frame encoding i-ppoi has been subcloned, and the endonuclease has been overproduced in e. coli. purified recombi ... | 1997 | 9416623 |
| specificity and direction of depolymerization of beta-poly(l-malate) catalysed by polymalatase from physarum polycephalum--fluorescence labeling at the carboxy-terminus of beta-poly(l-malate). | beta-poly(l-malate), a major constituent of nuclei in plasmodia of physarum polycephalum, is enzymatically degraded to l-malate after secretion into the culture medium. this depolymerization is specifically catalysed by an endogenous polymalatase. the mode of action and the specificity criteria have been investigated by employing various chemical derivatives of beta-poly(l-malate), including substitution at the hydroxy-terminus and carboxy-terminus of the polymer, esterification of the pending a ... | 1997 | 9428678 |
| degenerate dna recognition by i-ppoi endonuclease. | the i-ppoi endonuclease is encoded by a group i intron found in the slime mold physarum polycephalum. to initiate homing of its encoding intron, i-ppoi catalyzes a specific double-stranded break within a 15-bp recognition site. the high substrate specificities of i-ppoi and other homing endonucleases make these enzymes valuable tools for genomic mapping and sequencing. here, we report on the ability of i-ppoi to cleave recognition sites that contain a wide variety of mutations generated randomly ... | 1998 | 9461409 |
| dry stress-induced phosphorylation of physarum actin. | protein phosphorylation plays important roles in a variety of stress responses. although plasmodium of physarum polycephalum rapidly grows and shows an active cytoplasmic streaming under nutrient and wet conditions, dry stress transforms plasmodium into a dormant state called sclerotium. sclerotium can change into plasmodium within several hours after addition of water. we herein report that more than half of actin in sclerotium was in a phosphorylated state. the in vivo phosphorylation site was ... | 1998 | 9464272 |
| multiple polypeptides immunologically related to beta-poly(l-malate) hydrolase (polymalatase) in the plasmodium of the slime mold physarum polycephalum. | plasmodia of physarum polycephalum contain large amounts of the cell-type-specific polyanion beta-poly(l-malate) and of a corresponding specific hydrolase (polymalatase), both expressed in the plasmodial form of the organism. we have partially purified polymalatase, the preparation consisting of several polypeptides, which could not be separated without destroying the hydrolase activity. polypeptides of 68 kda and 97 kda were identified as polymalatases. both were glycosylated, the 68-kda form g ... | 1998 | 9492311 |
| cloning and characterization of physarum polycephalum tectonins. homologues of limulus lectin l-6. | previous investigators have reported the presence of two dominant proteins, tectonin i (25 kda) and tectonin ii (39 kda), in nuclei and nuclear matrix from plasmodia of physarum polycephalum. we demonstrate, by a modification of the nuclear isolation protocol and by protease sensitivity, that the tectonins are not nuclear proteins but rather are located on the exterior surface of the plasma membrane. we report the sequences of cdnas of tectonins i and ii, which encode 217 and 353 amino acids, re ... | 1998 | 9497393 |
| mitochondrial dna rearrangements associated with mf plasmid integration and plasmodial longevity in physarum polycephalum. | plasmodial cultures of physarum polycephalum have defined life spans and undergo a reproducible decline (senescence) before losing the ability to be subcultured. studies of the mtdna of a long-lived physarum strain, which does not undergo senescence, revealed a 7. 9-kb insertion in its mtdna. this insertion is derived from a mitochondrial plasmid which enhances mitochondrial fusion and mtdna recombination. four different recombination events are required to convert the parental mtdna to the form ... | 1998 | 9508792 |