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951.
Paschen SA Waizenegger T Stan T Preuss M Cyrklaff M Hell K Rapaport D Neupert W 《Nature》2003,426(6968):862-866
The outer membranes of mitochondria and chloroplasts are distinguished by the presence of beta-barrel membrane proteins. The outer membrane of Gram-negative bacteria also harbours beta-barrel proteins. In mitochondria these proteins fulfil a variety of functions such as transport of small molecules (porin/VDAC), translocation of proteins (Tom40) and regulation of mitochondrial morphology (Mdm10). These proteins are encoded by the nucleus, synthesized in the cytosol, targeted to mitochondria as chaperone-bound species, recognized by the translocase of the outer membrane, and then inserted into the outer membrane where they assemble into functional oligomers. Whereas some knowledge has been accumulated on the pathways of insertion of proteins that span cellular membranes with alpha-helical segments, very little is known about how beta-barrel proteins are integrated into lipid bilayers and assembled into oligomeric structures. Here we describe a protein complex that is essential for the topogenesis of mitochondrial outer membrane beta-barrel proteins (TOB). We present evidence that important elements of the topogenesis of beta-barrel membrane proteins have been conserved during the evolution of mitochondria from endosymbiotic bacterial ancestors. 相似文献
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Zusammenfassung Die Isolierung von fünfneuen Triterpensäuren (« Commisäure-A bis -E », englisch « commic acid-A to -E ») als Methylester ausCommiphora glandulosa Harz wird beschrieben. Sie wurden als Acetate bzw. als die entsprechenden Alkohole charakterisiert.
We are indebted to Dr.H. Hürlimann for supplying the botanical information in this paper. 相似文献
We are indebted to Dr.H. Hürlimann for supplying the botanical information in this paper. 相似文献
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Vreugde S Erven A Kros CJ Marcotti W Fuchs H Kurima K Wilcox ER Friedman TB Griffith AJ Balling R Hrabé De Angelis M Avraham KB Steel KP 《Nature genetics》2002,30(3):257-258
Despite recent progress in identifying genes underlying deafness, there are still relatively few mouse models of specific forms of human deafness. Here we describe the phenotype of the Beethoven (Bth) mouse mutant and a missense mutation in Tmc1 (transmembrane cochlear-expressed gene 1). Progressive hearing loss (DFNA36) and profound congenital deafness (DFNB7/B11) are caused by dominant and recessive mutations of the human ortholog, TMC1 (ref. 1), for which Bth and deafness (dn) are mouse models, respectively. 相似文献
956.
Dominant and recessive deafness caused by mutations of a novel gene, TMC1, required for cochlear hair-cell function 总被引:15,自引:0,他引:15
Kurima K Peters LM Yang Y Riazuddin S Ahmed ZM Naz S Arnaud D Drury S Mo J Makishima T Ghosh M Menon PS Deshmukh D Oddoux C Ostrer H Khan S Riazuddin S Deininger PL Hampton LL Sullivan SL Battey JF Keats BJ Wilcox ER Friedman TB Griffith AJ 《Nature genetics》2002,30(3):277-284
Positional cloning of hereditary deafness genes is a direct approach to identify molecules and mechanisms underlying auditory function. Here we report a locus for dominant deafness, DFNA36, which maps to human chromosome 9q13-21 in a region overlapping the DFNB7/B11 locus for recessive deafness. We identified eight mutations in a new gene, transmembrane cochlear-expressed gene 1 (TMC1), in a DFNA36 family and eleven DFNB7/B11 families. We detected a 1.6-kb genomic deletion encompassing exon 14 of Tmc1 in the recessive deafness (dn) mouse mutant, which lacks auditory responses and has hair-cell degeneration. TMC1 and TMC2 on chromosome 20p13 are members of a gene family predicted to encode transmembrane proteins. Tmc1 mRNA is expressed in hair cells of the postnatal mouse cochlea and vestibular end organs and is required for normal function of cochlear hair cells. 相似文献
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