caa a22 4500 397557140 CHVBK 20180308164805.0 cr unu---uuuuu 161202e199607 xx s 000 0 eng 10.1093/oxfordjournals.jbchem.a021393 doi (NATIONALLICENCE)oxford-10.1093/oxfordjournals.jbchem.a021393 Factors Involved in the Activation of Pre-mRNA Splicing from Downstream Splicing Enhancers [Elektronische Daten] [Tilmann Achsel, Yoshiro Shimura] The excision of introns with weak polypyrimidine tracts at their 3′ splice sites can be enhanced by sequence elements in the downstream exon or by a downstream 5′ splice site. The enhancers inside the exon do not conform to a strict consensus, but they are generally rich in purines. Here, we show that members of the family of SR proteins recognize these elements. Not only does SF2/ASF activate many different polypurine enhancers, but also at least one other SR protein, most likely SC35, is active as well. The degree of splicing activation varies with the polypurine enhancers and the SR proteins. Further, we show that the similar activation by downstream 5′ splice sites requires U1 snRNP, which is not the case with purine-rich enhancers. These results are consistent with a model showing that U1 snRNP binds to the 5′ splice site and SR proteins to exonic sequences upstream of the 5′ splice site. Both interact with U2AF at the 3′ splice site. This represents a molecular explanation for the exon recognition which is important for splice site selection in mammals. © 1996 BY THE JOURNAL OF BIOCHEMISTRY Regular Papers nationallicence exonic enhancer nationallicence pre-mRNA splicing nationallicence SR proteins nationallicence transacting factors nationallicence U1 snRNP nationallicence Achsel Tilmann Department of Biophysics, Faculty of Science, Kyoto University, Sakyo-ku, Kyoto 606 aut Shimura Yoshiro Department of Biophysics, Faculty of Science, Kyoto University, Sakyo-ku, Kyoto 606 aut The Journal of Biochemistry Oxford University Press 120/1(1996-07), 53-60 0021-924X 120:1<53 1996 120 jbchem https://doi.org/10.1093/oxfordjournals.jbchem.a021393 text/html Onlinezugriff via DOI 1 other jats NATIONALLICENCE 856 40 https://doi.org/10.1093/oxfordjournals.jbchem.a021393 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Achsel Tilmann Department of Biophysics, Faculty of Science, Kyoto University, Sakyo-ku, Kyoto 606 aut NATIONALLICENCE 700 1- Shimura Yoshiro Department of Biophysics, Faculty of Science, Kyoto University, Sakyo-ku, Kyoto 606 aut NATIONALLICENCE 773 0- The Journal of Biochemistry Oxford University Press 120/1(1996-07), 53-60 0021-924X 120:1<53 1996 120 jbchem Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford