Interaction of mammalian splicing factor SF3a with U2 snRNP and relation of its 60-kD subunit to yeast PRP9.
In the assembly of a prespliceosome, U2 small nuclear ribonucleoprotein (snRNP) functions in pre-messenger RNA (mRNA) splicing together with splicing factors (SFs) 3a, SF3b, and several other proteins. The 17S but not the 12S form of U2 snRNP is active in splicing-complex formation. Here it is shown that the SF3a subunits correspond to three of the 17S U2 snRNP-specific polypeptides. SF3a interacts with U2 snRNP in the presence of SF3b to generate a structure similar to 17S U2 snRNP, which suggests a function for SF3a and SF3b in the incorporation of U2 snRNP into the spliceosome. Furthermore, the 60-kilodalton subunit of SF3a is related to the yeast splicing protein PRP9.
Brosi
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Département de Biologie Cellulaire, Sciences III, Université de Genève, Switzerland.
Gröning
K
K
Behrens
S E
SE
Lührmann
R
R
Krämer
A
A
D000255:Adenosine Triphosphate / Q000378:metabolism; D003429:Cross Reactions; D004591:Electrophoresis, Polyacrylamide Gel; D005656:Fungal Proteins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D009687:Nuclear Proteins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D012326:RNA Splicing; D000072260:RNA Splicing Factors; D016601:RNA-Binding Proteins; D017413:Ribonucleoprotein, U2 Small Nuclear / Q000737:chemistry / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D017381:Spliceosomes / Q000378:metabolism*
D005656:Fungal Proteins; D009687:Nuclear Proteins; C065574:PRP9 protein, S cerevisiae; D000072260:RNA Splicing Factors; D016601:RNA-Binding Proteins; D017413:Ribonucleoprotein, U2 Small Nuclear; D029701:Saccharomyces cerevisiae Proteins; D000255:Adenosine Triphosphate