Comparison of the effects of class 1 and class 2 heparin-binding growth factors on protein synthesis and actin mRNA expression in BALB/c-3T3 cells.
Biological effects of class 1 or class 2 heparin-binding growth factors (HBGFs) were compared in BALB/c-3T3 cells. Changes in protein synthesis, as monitored by two-dimensional gel electrophoresis, reveal that while both HBGFs induce the same changes in the synthesis of intracellular proteins, class 2 HBGF selectively increases the synthesis of a 43-kD extracellular protein. Heparin, which potentiates the mitogenic activity of class 1 but not class 2 HBGF, does not potentiate the changes in protein synthesis elicited by HBGF-1. Since each HBGF increases actin synthesis, regulation of actin mRNA expression was examined. Actin mRNA levels increase rapidly and transiently in response to either HBGF, and similar superinduction responses are observed in the presence of HBGF and cycloheximide. Although the maximum increase in actin mRNA stimulated by either HBGF is similar, the levels of mRNA induced by class 2 HBGF remain elevated up to 48 hours compared to the level induced by class 1 HBGF. These results imply that in the same cell type class 1 and class 2 HBGFs may modulate some biological effects differently.
Rybak
S M
SM
Department of Pathology, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts 02115.
Lobb
R R
RR
Fett
J W
JW
D000199:Actins / Q000096:biosynthesis / Q000235:genetics*; D000818:Animals; D002460:Cell Line; D003513:Cycloheximide / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D016220:Fibroblast Growth Factor 1; D016222:Fibroblast Growth Factor 2; D006133:Growth Substances / Q000494:pharmacology*; D006493:Heparin / Q000494:pharmacology*; D051379:Mice; D008807:Mice, Inbred BALB C; D012333:RNA, Messenger / Q000378:metabolism*
D000199:Actins; D006133:Growth Substances; D012333:RNA, Messenger; D016222:Fibroblast Growth Factor 2; D016220:Fibroblast Growth Factor 1; D006493:Heparin; D003513:Cycloheximide