Distinct functions of SR proteins in recruitment of U1 small nuclear ribonucleoprotein to alternative 5' splice sites.
Alternative splicing of precursor messenger RNAs (pre-mRNAs) is an important mechanism for the regulation of gene expression. The members of the SR protein family of pre-mRNA splicing factors have distinct functions in promoting alternative splice site usage. Here we show that SR proteins are required for the first step of spliceosome assembly, interaction of the U1 small nuclear ribonucleoprotein complex (U1 snRNP) with the 5' splice site of the pre-mRNA. Further, we find that individual SR proteins have distinct abilities to promote interaction of U1 snRNP with alternative 5' splice junctions. These results suggest that SR proteins direct 5' splice site selection by regulation of U1 snRNP assembly onto the pre-mRNA.
Zahler
A M
AM
Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98104, USA.
Roth
M B
MB
D017398:Alternative Splicing; D000818:Animals; D000952:Antigens, Polyomavirus Transforming / Q000096:biosynthesis; D001483:Base Sequence; D002417:Cattle; D017931:DNA Primers; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000302:isolation & purification / Q000378:metabolism*; D010750:Phosphoproteins / Q000302:isolation & purification / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012322:RNA Precursors / Q000302:isolation & purification / Q000378:metabolism*; D016601:RNA-Binding Proteins; D017412:Ribonucleoprotein, U1 Small Nuclear / Q000302:isolation & purification / Q000378:metabolism*; D000068103:Serine-Arginine Splicing Factors; D013539:Simian virus 40 / Q000235:genetics; D013698:Templates, Genetic; D013950:Thymus Gland / Q000378:metabolism
D000952:Antigens, Polyomavirus Transforming; D017931:DNA Primers; D009687:Nuclear Proteins; D010750:Phosphoproteins; D012322:RNA Precursors; D016601:RNA-Binding Proteins; D017412:Ribonucleoprotein, U1 Small Nuclear; D000068103:Serine-Arginine Splicing Factors