Regulation of cyclin D-dependent kinase activity in rat liver regeneration.
The regulation of cyclin D-dependent kinase activity in tissue regeneration in vivo has not been fully described. In young adult rat liver after 70% partial hepatectomy, the association of cyclin D1 with cdk4 was significantly promoted during G1 phase and was maximal at 18 hr, corresponding mainly to late G1. Cyclin D1-dependent kinase activity also strongly increased during G1 phase. The timing of the induction of cyclin D1 / cdk4 complex assembly correlated well with that of cyclin D1-dependent kinase activity. At 18 hr after partial hepatectomy, the amounts of CDK inhibitors p21(CIP1) and p27(KIP1) were also maximal, while only one-tenth of p21(CIP1) and of p27(KIP1) was associated with cyclin D1. These findings suggest that cyclin D1, cdk4 and their association act as promoting factors, and that both p21(CIP1) and p27(KIP1) may have physiological functions as adaptor proteins in additions to their roles as CDK inhibitors in rat liver regeneration.
Kato
A
A
1st Department of Internal Medicine, Saitama Medical Center, Saitama Medical School, 1981 Tsujido, Kamoda, Saitama, Kawagoe, 350-8550, Japan.
Ota
S
S
Bamba
H
H
Wong
R M
RM
Ohmura
E
E
Imai
Y
Y
Matsuzaki
F
F
D000818:Animals; D002453:Cell Cycle / Q000502:physiology; D018797:Cell Cycle Proteins; D019938:Cyclin D1 / Q000378:metabolism; D051358:Cyclin-Dependent Kinase 4; D050759:Cyclin-Dependent Kinase Inhibitor p21; D050760:Cyclin-Dependent Kinase Inhibitor p27; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D016213:Cyclins / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D006498:Hepatectomy; D007120:Immunochemistry; D007399:Interphase / Q000502:physiology; D008115:Liver Regeneration / Q000502:physiology*; D008297:Male; D008869:Microtubule-Associated Proteins / Q000494:pharmacology; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D025521:Tumor Suppressor Proteins
C493958:Cdkn1a protein, rat; C493962:Cdkn1b protein, rat; D018797:Cell Cycle Proteins; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D004791:Enzyme Inhibitors; D008869:Microtubule-Associated Proteins; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D025521:Tumor Suppressor Proteins; D019938:Cyclin D1; D050760:Cyclin-Dependent Kinase Inhibitor p27; C495903:Cdk4 protein, rat; D051358:Cyclin-Dependent Kinase 4; D018844:Cyclin-Dependent Kinases