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：2015
卷号：112
期号：28
页码：8608-8613
DOI：10.1073/pnas.1506282112
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：SignificanceThe protein fused-in-sarcoma (FUS) is mutated to cause the neurodegenerative disease amyotrophic lateral sclerosis, but its normal cellular role remains to be understood. Previous work showed that FUS associates with both RNA polymerase II (RNAP II) and the essential splicing factor U1 small nuclear ribonucleoprotein (snRNP). Here we were able to directly investigate the functional significance of these interactions using an in vitro system. We show that FUS is essential for the interaction between U1 snRNP and RNAP II and that FUS must be present during the RNAP II transcription reaction in order for splicing to occur. Together, these data indicate that FUS mediates an interaction between RNAP II and U1 snRNP, thereby physically and functionally coupling transcription to splicing. Pre-mRNA splicing is coupled to transcription by RNA polymerase II (RNAP II). We previously showed that U1 small nuclear ribonucleoprotein (snRNP) associates with RNAP II, and both RNAP II and U1 snRNP are also the most abundant factors associated with the protein fused-in-sarcoma (FUS), which is mutated to cause the neurodegenerative disease amyotrophic lateral sclerosis. Here, we show that an antisense morpholino that base-pairs to the 5' end of U1 snRNA blocks splicing in the coupled system and completely disrupts the association between U1 snRNP and both FUS and RNAP II, but has no effect on the association between FUS and RNAP II. Conversely, we found that U1 snRNP does not interact with RNAP II in FUS knockdown extracts. Moreover, using these extracts, we found that FUS must be present during the transcription reaction in order for splicing to occur. Together, our data lead to a model that FUS functions in coupling transcription to splicing via mediating an interaction between RNAP II and U1 snRNP.
关键词：ALS ; coupling transcription to splicing ; RNA polymerase II ; U1 snRNP
