title: Characterization of two SV40 early mRNAs and evidence for a nuclear "prespliced" RNA species.
abstract: Using in vitro translation of sucrose-gradient fractionated cytoplasmic mRNA from SV40-infected cells, we have shown that a deletion in the region mapping between 0.54--0.59 reduced the size of mRNA for small-t but not the size of mRNA for large-T. Mutants with a deletion in this region were shown to produce in vivo either shortened small-t or no small-t, and normal large-T. Similarly, in vitro translation of poly(A)+cytoplasmic RNA from cells infected with these mutants gave the same results. On the other hand in vitro translation of poly(A)+nuclear RNA from the mutants which made no small-t produced a small-t derivative possibly synthesized from a prespliced RNA species. We have also shown that poly(A)+nuclear RNA from mutant dl 2122 produced two small-t related proteins: one of these (MW: 11K) probably represents the product of a "prespliced" RNA, the other (MW: 17K) which is also found in the cytoplasm represents the product of the mutant specific small-t mRNA.
mesh_terms: D000951:Antigens, Neoplasm / Q000235:genetics*; D000956:Antigens, Viral / Q000235:genetics; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002872:Chromosome Deletion; D005814:Genes, Viral; D008970:Molecular Weight; D011061:Poly A / Q000378:metabolism; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics*; D012367:RNA, Viral / Q000235:genetics; D013539:Simian virus 40 / Q000235:genetics*
chemical_list: D000951:Antigens, Neoplasm; D000956:Antigens, Viral; D012333:RNA, Messenger; D012367:RNA, Viral; D011061:Poly A