A mammalian protein of 220 kDa binds pre-mRNAs in the spliceosome: a potential homologue of the yeast PRP8 protein.
A mammalian protein of approximately 220 kDa (p220) was UV-crosslinked to precursor mRNAs (pre-mRNAs) under splicing conditions. The kinetics and biochemical requirements of the UV-crosslinking of p220 corresponded to the kinetics and biochemical requirements of spliceosome formation. On Western blots, antibodies against the yeast splicing factor PRP8 recognized a doublet of proteins, the faster migrating of which comigrated with p220. Furthermore, UV-crosslinked p220 was immunoprecipitated with anti-PRP8 antisera. These results suggest structural conservation of the splicing factor PRP8 from yeast to mammals and show that this protein is in close proximity to the pre-mRNA in the spliceosome.
Garcia-Blanco
M A
MA
Center for Cancer Research, Massachusetts Institute of Technology, Cambridge 02139.
Anderson
G J
GJ
Beggs
J
J
Sharp
P A
PA
D015153:Blotting, Western; D002467:Cell Nucleus / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D008961:Models, Structural; D008970:Molecular Weight; D011485:Protein Binding; D012322:RNA Precursors / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D012326:RNA Splicing / Q000528:radiation effects; D012261:Ribonucleoproteins / Q000302:isolation & purification / Q000378:metabolism* / Q000528:radiation effects; D017411:Ribonucleoproteins, Small Nuclear; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D014466:Ultraviolet Rays
D012322:RNA Precursors; D012261:Ribonucleoproteins; D017411:Ribonucleoproteins, Small Nuclear