| expression in yeast of the t-urf13 protein from texas male-sterile maize mitochondria confers sensitivity to methomyl and to texas-cytoplasm-specific fungal toxins. | the mitochondrial gene t-urf13 from maize (zea mays l.) with texas male-sterile (t) cytoplasm codes for a unique 13 kd polypeptide, t-urf13, which is implicated in cytoplasmic male sterility and sensitivity to the insecticide methomyl and to host-specific fungal toxins produced by helminthosporium maydis race t (hmt toxin) and phyllosticta maydis (pm toxin). a chimeric gene coding for t-urf13 fused to the mitochondrial targeting peptide from the neurospora crassa atp synthase subunit 9 precursor ... | 1990 | 2303028 |
| the relationship between the mitochondrial gene t-urf13 and fungal pathotoxin sensitivity in maize. | mitochondria isolated from maize containing cms-t cytoplasm are specifically sensitive to pathotoxins (t-toxins) produced by the fungi bipolaris maydis race t and phyllosticta maydis. t-toxins interact with a 13 kda membrane-bound toxin receptor protein, urf13, to produce hydrophillic pores in the membrane. expression of urf13 in escherichia coli produces bacterial cells that form hydrophillic pores in the plasma membrane when exposed to t-toxin or methomyl. topological studies have established ... | 1995 | 7599214 |
| n,n'-dicyclohexylcarbodiimide cross-linking suggests a central core of helices ii in oligomers of urf13, the pore-forming t-toxin receptor of cms-t maize mitochondria. | urf13 is a mitochondrially encoded, integral membrane protein found only in maize carrying the cms-t cytoplasm. urf13 is associated with cytoplasmic male sterility, texas type, and causes susceptibility to the fungal pathogens bipolaris maydis race t and phyllosticta maydis. urf13 is predicted to contain three transmembrane alpha-helices and is a receptor for the pathotoxins (t-toxins) produced by b. maydis race t and p. maydis. binding of t-toxin to urf13 leads to membrane permeability. cross-l ... | 1994 | 8058790 |
| cross-linking and disulfide bond formation of introduced cysteine residues suggest a modified model for the tertiary structure of urf13 in the pore-forming oligomers. | urf13 is a mitochondrially encoded protein in the inner mitochondrial membrane of maize (zea mays l.) carrying the cms-t cytoplasm. this protein is responsible for texas-type cytoplasmic sterility and is a ligand-gated, pore-forming receptor for the pathotoxins of fungal pathogens bipolaris maydis race t and phyllosticta maydis. urf13 contains three transmembrane alpha-helices, with amphipathic helices ii and iii likely involved in pore formation, and is present as oligomers in cms-t maize mitoc ... | 1998 | 9633611 |
| identity and conservation of mating type genes in geographically diverse isolates of phaeosphaeria nodorum. | mating type idiomorphs (mat1-1 and mat1-2) were identified from the heterothallic loculoascomycete phaeosphaeria nodorum (wheat biotype) using dna from a pair of isolates from poland and georgia, usa that are known to mate. mat predicted proteins of p. nodorum are similar in sequence and in phylogenetic relationship to those described for other loculoascomycetes such as cochliobolus spp., alternaria alternata, and didymella zeae-maydis. the organization of the mat locus of the p. nodorum differs ... | 2003 | 12948511 |
| the binding of host-selective toxin analogs to mitochondria from normal and ;texas' male sterile cytoplasm maize. | tritium-labeled toxin analogs were prepared by reduction with nab(3)h(4) of either the toxin from helminthosporium maydis race t or a toxin component from phyllosticta maydis. these reduced analogs had high radiochemical specific activities, high biological activities, and plant specificities identical to the native toxins. a filtration assay was developed to test the binding of these labeled analogs to isolated mitochondria. binding was not energy dependent nor was there measurable matrical upt ... | 1987 | 16665353 |
| dissipation of the membrane potential in susceptible corn mitochondria by the toxin of helminthosporium maydis, race t, and toxin analogs. | we have tested directly the effect of helminthosporium maydis t (hmt) toxin and various analogs on the membrane potential formed in mitochondria isolated from a texas (t) cytoplasmic male-sterile and a normal (n) corn. atp, malate or succinate generated a membrane potential (negative inside) as monitored by the absorbance change of a cationic dye, safranine. the relative membrane potential (deltapsi) could also be detected indirectly as (45)ca(2+) uptake. hmt toxin added to t mitochondria dissip ... | 1987 | 16665500 |
| six new genes required for production of t-toxin, a polyketide determinant of high virulence of cochliobolus heterostrophus to maize. | southern corn leaf blight, one of the worst plant disease epidemics in modern history, was caused by cochliobolus heterostrophus race t, which produces t-toxin, a determinant of high virulence to maize carrying texas male sterile cytoplasm. the genetics of t-toxin production is complex and the evolutionary origin of associated genes is uncertain. it is known that ability to produce t-toxin requires three genes encoded at two unlinked loci, tox1a and tox1b, which map to the breakpoints of a recip ... | 2010 | 20192833 |