Growth regulated expression of B-myb in fibroblasts and hematopoietic cells.
The B-myb cDNA has extensive sequence similarities to the c-myb proto-oncogene, but, at variance with c-myb, it is expressed in cells other than hematopoietic cells. In this paper, we show that (1) B-myb is expressed in mouse, human, and hamster fibroblasts; (2) B-myb mRNA levels are growth-regulated in both fibroblasts and peripheral blood mononuclear cells; (3) by its mode of growth regulation (peak of expression, behavior in G1-specific temperature sensitive (ts) mutants and in the presence of cycloheximide), B-myb can be classified, like c-myb, thymidine kinase, PCNA, and others, as a late growth-regulated gene; (4) B-myb mRNA levels decrease when HL-60 cells are induced to differentiate; and (5) the increase in mRNA levels in serum-stimulated cells is only partially explained by an increase in rate of transcription. The possibility that the B-myb gene may be the equivalent in fibroblasts and epithelial cells of the c-myb proto-oncogene of hematopoietic cells is discussed.
Reiss
K
K
Department of Pathology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140.
Travali
S
S
Calabretta
B
B
Baserga
R
R
D000818:Animals; D002453:Cell Cycle; D002454:Cell Differentiation; D002455:Cell Division; D002460:Cell Line; D005347:Fibroblasts / Q000166:cytology / Q000502:physiology; D005786:Gene Expression Regulation; D015972:Gene Expression Regulation, Neoplastic; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000502:physiology*; D006801:Humans; D008214:Lymphocytes / Q000502:physiology; D009857:Oncogenes; D010957:Plasmids; D000090063:Proto-Oncogene Mas; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D012333:RNA, Messenger / Q000235:genetics; D014158:Transcription, Genetic
C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D012333:RNA, Messenger; D012313:RNA