Abstract
The ansamycin antibiotic herbimycin A is a potent tyrosine kinase inhibitor and reduces the growth rate of various types of mammalian cells. When quiescent Rat6 fibroblast cells were treated with herbimycin A, serum-induced expression of cyclin D1 was inhibited, and this was associated with inhibition of G1 phase progression. However, herbimycin A also inhibited serum-induced G1 progression in derivatives of the Rat6 fibroblast cell line that stably overexpress a human cyclin D1 cDNA (R6ccnD1#4 cells), without affecting the expression levels of G1 cyclins. We found that herbimycin A prevented serum-induced downregulation of the cyclin-dependent kinase inhibitor p27(Kip1), thereby leading to inactivation of the protein kinase activity of CDK2. These results suggest that herbimycin A inhibits a tyrosine kinase(s) that plays a role in degradation of the p27(Kop1) protein.
Copyright 2000 Academic Press.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Animals
-
Benzoquinones
-
CDC2-CDC28 Kinases*
-
Cell Cycle / drug effects*
-
Cell Cycle Proteins*
-
Cell Line
-
Culture Media, Serum-Free
-
Cyclin D1 / genetics*
-
Cyclin D1 / physiology*
-
Cyclin-Dependent Kinase 2
-
Cyclin-Dependent Kinase Inhibitor p27
-
Cyclin-Dependent Kinases / antagonists & inhibitors
-
Cyclin-Dependent Kinases / metabolism
-
Enzyme Inhibitors / metabolism*
-
Fibroblasts
-
G1 Phase / drug effects
-
Gene Expression Regulation / drug effects
-
Humans
-
Lactams, Macrocyclic
-
Microtubule-Associated Proteins / metabolism*
-
Protein Serine-Threonine Kinases / metabolism
-
Quinones / pharmacology*
-
Rats
-
Recombinant Proteins / metabolism
-
Rifabutin / analogs & derivatives
-
S Phase / drug effects
-
Transfection
-
Tumor Suppressor Proteins*
Substances
-
Benzoquinones
-
Cdkn1b protein, rat
-
Cell Cycle Proteins
-
Culture Media, Serum-Free
-
Enzyme Inhibitors
-
Lactams, Macrocyclic
-
Microtubule-Associated Proteins
-
Quinones
-
Recombinant Proteins
-
Tumor Suppressor Proteins
-
Cyclin D1
-
Cyclin-Dependent Kinase Inhibitor p27
-
Rifabutin
-
herbimycin
-
Protein Serine-Threonine Kinases
-
CDC2-CDC28 Kinases
-
CDK2 protein, human
-
Cdk2 protein, rat
-
Cyclin-Dependent Kinase 2
-
Cyclin-Dependent Kinases