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951.
Recurrent de novo point mutations in lamin A cause Hutchinson-Gilford progeria syndrome 总被引:36,自引:0,他引:36
Eriksson M Brown WT Gordon LB Glynn MW Singer J Scott L Erdos MR Robbins CM Moses TY Berglund P Dutra A Pak E Durkin S Csoka AB Boehnke M Glover TW Collins FS 《Nature》2003,423(6937):293-298
Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disorder characterized by features reminiscent of marked premature ageing. Here, we present evidence of mutations in lamin A (LMNA) as the cause of this disorder. The HGPS gene was initially localized to chromosome 1q by observing two cases of uniparental isodisomy of 1q-the inheritance of both copies of this material from one parent-and one case with a 6-megabase paternal interstitial deletion. Sequencing of LMNA, located in this interval and previously implicated in several other heritable disorders, revealed that 18 out of 20 classical cases of HGPS harboured an identical de novo (that is, newly arisen and not inherited) single-base substitution, G608G(GGC > GGT), within exon 11. One additional case was identified with a different substitution within the same codon. Both of these mutations result in activation of a cryptic splice site within exon 11, resulting in production of a protein product that deletes 50 amino acids near the carboxy terminus. Immunofluorescence of HGPS fibroblasts with antibodies directed against lamin A revealed that many cells show visible abnormalities of the nuclear membrane. The discovery of the molecular basis of this disease may shed light on the general phenomenon of human ageing. 相似文献
952.
Kappelman J Rasmussen DT Sanders WJ Feseha M Bown T Copeland P Crabaugh J Fleagle J Glantz M Gordon A Jacobs B Maga M Muldoon K Pan A Pyne L Richmond B Ryan T Seiffert ER Sen S Todd L Wiemann MC Winkler A 《Nature》2003,426(6966):549-552
Afro-Arabian mammalian communities underwent a marked transition near the Oligocene/Miocene boundary at approximately 24 million years (Myr) ago. Although it is well documented that the endemic paenungulate taxa were replaced by migrants from the Northern Hemisphere, the timing and evolutionary dynamics of this transition have long been a mystery because faunas from about 32 to 24 Myr ago are largely unknown. Here we report a late Oligocene fossil assemblage from Ethiopia, which constrains the migration to postdate 27 Myr ago, and yields new insight into the indigenous faunal dynamics that preceded this event. The fauna is composed of large paenungulate herbivores and reveals not only which earlier taxa persisted into the late Oligocene epoch but also demonstrates that one group, the Proboscidea, underwent a marked diversification. When Eurasian immigrants entered Afro-Arabia, a pattern of winners and losers among the endemics emerged: less diverse taxa such as arsinoitheres became extinct, moderately species-rich groups such as hyracoids continued into the Miocene with reduced diversity, whereas the proboscideans successfully carried their adaptive radiation out of Afro-Arabia and across the world. 相似文献
953.
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
957.
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
958.
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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960.