TY - JOUR
T1 - General splicing factors SF2 and SC35 have equivalent activities in vitro, and both affect alternative 5′ and 3′ splice site selection
AU - Fu, Xiang Dong
AU - Mayeda, Akila
AU - Maniatis, Tom
AU - Krainer, Adrian R.
PY - 1992/12/1
Y1 - 1992/12/1
N2 - The human pre-mRNA splicing factors SF2 and SC35 have similar electrophoretic mobilities, and both of them contain an N-terminal ribonucleoprotein (RNP)-type RNA-recognition motif and a C-terminal arginine/serine-rich domain. However, the two proteins are encoded by different genes and display only 31% amino acid sequence identity. Here we report a systematic comparison of the splicing activities of recombinant SF2 and SC35. We find that either protein can reconstitute the splicing activity of S100 extracts and of SC35-immunodepleted nuclear extracts. Previous studies revealed that SF2 influences alternative 5′ splice site selection in vitro, by favoring proximal over distal 5′ splice sites, and that the A1 protein of heterogeneous nuclear RNP counteracts this effect. We now show that SC35 has a similar effect on competing 5′ splice sites and is also antagonized by A1 protein. In addition, we report that both SF2 and SC35 also favor the proximal site in a pre-mRNA containing duplicated 3′ splice sites, but this effect is not modulated by Al. We conclude that SF2 and SC35 are distinct splicing factors, but they display indistinguishable splicing activities in vitro.
AB - The human pre-mRNA splicing factors SF2 and SC35 have similar electrophoretic mobilities, and both of them contain an N-terminal ribonucleoprotein (RNP)-type RNA-recognition motif and a C-terminal arginine/serine-rich domain. However, the two proteins are encoded by different genes and display only 31% amino acid sequence identity. Here we report a systematic comparison of the splicing activities of recombinant SF2 and SC35. We find that either protein can reconstitute the splicing activity of S100 extracts and of SC35-immunodepleted nuclear extracts. Previous studies revealed that SF2 influences alternative 5′ splice site selection in vitro, by favoring proximal over distal 5′ splice sites, and that the A1 protein of heterogeneous nuclear RNP counteracts this effect. We now show that SC35 has a similar effect on competing 5′ splice sites and is also antagonized by A1 protein. In addition, we report that both SF2 and SC35 also favor the proximal site in a pre-mRNA containing duplicated 3′ splice sites, but this effect is not modulated by Al. We conclude that SF2 and SC35 are distinct splicing factors, but they display indistinguishable splicing activities in vitro.
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M3 - Article
C2 - 1454802
AN - SCOPUS:0026437581
SN - 0027-8424
VL - 89
SP - 11224
EP - 11228
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 23
ER -