Coexistence of a c-myc mRNA initiated in intron 1 with the normal c-myc mRNA and similar regulation of both transcripts in mammalian cells.
We previously described a c-myc mRNA initiated within intron 1 at a major start site designated P3. This mRNA was observed in tumorigenic murine cells with no detectable rearrangement of the c-myc gene. In the present study, we report that P3 mRNA also coexists with the P1/P2 c-myc transcript in non-tumorigenic murine cell lines and that a c-myc mRNA which appears to be an equivalent of the murine P3 transcript is found in various rat and human cells. These data suggest that P3 represents a promoter of the normal, non-rearranged mammalian c-myc gene. Furthermore, both P1/P2 and P3 mRNA levels are similarly regulated by cycloheximide and by dimethylsulfoxide (DMSO) in murine erythroleukemia Friend cells.
Ray
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D
INSERM U-248, Faculté de Médecine Lariboisière, Paris, France.
Robert-Lézénès
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D000818:Animals; D002460:Cell Line; D003513:Cycloheximide / Q000494:pharmacology; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D006801:Humans; D007438:Introns; D004915:Leukemia, Erythroblastic, Acute / Q000378:metabolism; D051379:Mice; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger / Q000032:analysis*; D051381:Rats; D014158:Transcription, Genetic
D011518:Proto-Oncogene Proteins; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; D003513:Cycloheximide; D004121:Dimethyl Sulfoxide