期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1999
卷号：96
期号：20
页码：11167-11172
DOI：10.1073/pnas.96.20.11167
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Spinal muscular atrophy (SMA) is a common motor neuron degenerative disease and the leading genetic cause of death of young children. The survival of motor neurons (SMN) gene, the SMA disease gene, is homozygously deleted or mutated in more than 98% of SMA patients. The SMN protein interacts with itself, with SMN-interacting protein 1, and with several spliceosomal small nuclear ribonucleoprotein (snRNP) Sm proteins. A complex containing SMN plays a critical role in spliceosomal snRNP assembly and in pre-mRNA splicing. SMN mutants found in SMA patients show reduced self-association and lack the capacity to regenerate the splicing machinery. Here we demonstrate that SMN mutants found in SMA patients are defective in binding to Sm proteins. Moreover, we show that SMN, but not mutants found in SMA patients, can form large oligomers and that SMN oligomerization is required for high-affinity binding to spliceosomal snRNP Sm proteins. These findings directly link the impaired interaction between SMN and Sm proteins to a defect in snRNP metabolism and to SMA.
