Role of RNA structures in c-myc and c-fos gene regulations.
Proto-oncogenes c-myc and c-fos are subjected to a complex set of controls operating both at the transcriptional and post-transcriptional levels. We report here that: (i) antisense transcription occurs at the murine c-myc locus. However, its biological significance remains to be established; (ii) transcription of both genes is regulated in various situations by a block to elongation of nascent RNA chains. In the case of c-myc, the blockade involves a RNA structure whose nature remains unknown; (iii) elements responsible for the high degree of instability of c-myc and c-fos mRNAs reside in their 3' non-coding regions. A U-rich region, reminiscent of that present in the granulocyte-monocyte colony-stimulating factor mRNA destabilizer, is likely to be involved in the rapid degradation of c-fos mRNA; (iv) exon 1 substitution by intron 1-derived sequences lessens or negates the effect of the 3' destabilizer in abnormal c-myc RNAs from Burkitt's lymphomas and mouse plasmacytomas.
Piechaczyk
M
M
Laboratoire de Biologie Moléculaire, UA CNRS 1191, USTL, Montpellier, France.
Blanchard
J M
JM
Bonnieu
A
A
Fort
P
P
Mechti
N
N
Rech
J
J
Cuny
M
M
Marty
L
L
Ferré
F
F
Lebleu
B
B
D000818:Animals; D001483:Base Sequence; D002645:Chickens; D005786:Gene Expression Regulation; D006801:Humans; D008969:Molecular Sequence Data; D011519:Proto-Oncogenes; D012313:RNA / Q000235:genetics; D012323:RNA Processing, Post-Transcriptional; D016372:RNA, Antisense; D012333:RNA, Messenger / Q000037:antagonists & inhibitors; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D014158:Transcription, Genetic
D016372:RNA, Antisense; D012333:RNA, Messenger; D012313:RNA