SV40-induced expression of mouse gene 24p3 involves a post-transcriptional mechanism.
SV40 and polyoma virus induce a mitotic host reaction in confluent, Go-arrested primary mouse kidney cell cultures. To define the primary effects of infection we constructed a cDNA library corresponding to polyA+ mRNA isolated shortly after onset of polyoma T-antigen synthesis. By differential screening of the library we have isolated and then sequenced cDNA recombinant 24p3; determined by Northern blotting, 24p3 mRNA steady state levels increased in parallel with polyoma and SV40 T-antigen synthesis. Since this rapid and early increase was particularly striking (14-20 fold) in SV40-infected cells, we studied the molecular mechanism of induction in this virus-cell system. We show that wt SV40 large T-antigen is required for the increase in 24p3 mRNA levels. The results tend to exclude that this increase is due to an SV40-induced stabilization of the 24p3 mRNA, or to an SV40-induced stimulation of transcription of the 24p3 gene; they are compatible with the working hypothesis that SV40 large T-antigen increases the efficiency of processing, possibly splicing, of the 24p3 pre-mRNA. The biological implications of these results are discussed.
Hraba-Renevey
S
S
Department of Molecular Biology, University of Geneva, Switzerland.
Türler
H
H
Kress
M
M
Salomon
C
C
Weil
R
R
D000595:Amino Acid Sequence; D000818:Animals; D000952:Antigens, Polyomavirus Transforming / Q000096:biosynthesis; D001483:Base Sequence; D015152:Blotting, Northern; D002478:Cells, Cultured; D005786:Gene Expression Regulation; D051379:Mice; D008969:Molecular Sequence Data; D011120:Polyomavirus / Q000502:physiology; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000378:metabolism*; D013539:Simian virus 40 / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic
D000952:Antigens, Polyomavirus Transforming; D012333:RNA, Messenger