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：1996
卷号：93
期号：15
页码：7582-7587
DOI：10.1073/pnas.93.15.7582
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：A purine-rich splicing enhancer from a constitutive exon has been shown to shift the alternative splicing of calcitonin/CGRP pre-mRNA in vivo. Here, we demonstrate that the native repetitive GAA sequence comprises the optimal enhancer element and specifically binds a saturable complex of proteins required for general splicing in vitro. This complex contains a 37-kDa protein that directly binds the repetitive GAA sequence and SRp40, a member of the SR family of non-snRNP splicing factors. While purified SR proteins do not stably bind the repetitive GAA element, exogenous SR proteins become associated with the GAA element in the presence of nuclear extracts and stimulate GAA-dependent splicing. These results suggest that repetitive GAA sequences enhance splicing by binding a protein complex containing a sequence-specific RNA binding protein and a general splicing activator that, in turn, recruit additional SR proteins. This type of mechanism resembles the tra/tra-2-dependent recruitment of SR proteins to the Drosophila doublesex alternative splicing regulatory element.
