Translational regulation of SV40 early mRNA defines a new viral protein.
SP6-initiated in vitro transcripts, representing the three major classes of early SV40 mRNAs, early-early (EE) and two late-early (LE) transcripts, were assayed by in vitro translation to compare their relative efficiencies for synthesis of the SV40 T antigens. The presence of one or two potential AUG initiator codons in the leader sequences of the LE RNAs inhibits efficient translation from the downstream T-antigen initiator AUG. In vitro translation of the capped form of the shorter SV40 LE RNA resulted in the synthesis of a 2.7-kd protein. In vivo pulse labeling of SV40-infected CV-1 cells demonstrated the accumulation of a peptide of similar size at late times after lytic infection, indicating that it is an authentic viral protein encoded by the early leader sequence of SV40.
D000818:Animals; D002460:Cell Line; D010957:Plasmids; D014176:Protein Biosynthesis; D021382:Protein Sorting Signals / Q000096:biosynthesis; D012333:RNA, Messenger / Q000378:metabolism*; D012367:RNA, Viral / Q000378:metabolism*; D013539:Simian virus 40 / Q000235:genetics*; D013698:Templates, Genetic; D014764:Viral Proteins / Q000096:biosynthesis / Q000235:genetics*
D021382:Protein Sorting Signals; D012333:RNA, Messenger; D012367:RNA, Viral; D014764:Viral Proteins