Mitogen‐stimulated events in nuclei of Swiss 3T3 cells Evidence for a direct link between changes of inositol lipids, protein kinase C requirement and the onset of DNA synthesis

FEBS Letters

Corps, A.N.²  Gilmour, R.S.²  Neri, L.M.³  Cocco, L.³  Manzoli, L.¹  Martelli, A.M.³ 

[1] Istituto di Morfologia Umana Normale, Universitá di Chieti, Bologna, Italy;Department of Biochemistry, AFRC Institute of Animal Physiology and Genetics Research, Babraham, Cambridge, UK;Istitut di Anatomia Umana Normale, Unversitá di Bologna e Ferrara Italy

关键词: Nucleus;    Mitogen;    Inositol lipid;    Swiss 3T3 cell;    Protein kinase C;    DNA synthesis;    PIP;    phosphatidylinositol 4-phosphate;    PIP2;    phosphatidylinositol 4;    5-diphosphate;    PA;    phosphatidic acid;    BrdU;    5-bromodeoxyuridine;    IGF-I;    insulin-like growth factor I;    IP3;    inositol 1;    4;    5-trisphosphate;    ATP;    adenosine trisphosphate;    PKC;    protein kinase C;    PS;    phosphatidyl-serine;    DAG;    1;    2-dioleyl-racglycerol);    SPH;    sphingosine;    EGTA;    ethylene glycol-bis(β-aminoethyl ether) N;    N;    N′;    N′-tetraacetic acid;   

DOI  :  10.1016/0014-5793(91)80598-W

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Two different clones of Swiss 3T3 cells belonging to the same original cell line have been obtained, one of which was unresponsive to mitogenic stimulation (e.g. insulin-like growth factor-I, bombesin, insulin-like growth factor-I + bombesin), while the other clone showed a very high rate of DNA synthesis under identical conditions as demonstrated by 5-bromodeoxyuridine incorporation. Both types of cells expressed the IGF-I receptor and showed high contact inhibition. When highly purified nuclei from responsive cells, treated for a short time with bombesin and insulin-like growth factor-I or insulin-like growth factor-I alone, were incubated with [γ-³²P]adenosine triphosphate, the labelling of phosphatidylinositol-mono- und diphosphate decreased when compared to controls, while this transient effect did not appear in the nuclei from unresponsive cells. Similarly nuclear protein kinase C is activated only in responsive cells. Therefore, it seems that a direct link exists between polyphosphoinositide metabolism, protein kinase C activation and the early events leading to cell division, since the rapid changes in the labelling of both phosphatidylinositol mono- and di-phosphate occur only in nuclei from Swiss 3T3 cells, which respond to the mitogenic stimulus determined by insulin-like growth factor-I on its own, or in combination with bombesin.

【 授权许可】

Unknown