Selective nuclear translocation of protein kinase C α in Swiss 3T3 cells treated with IGF‐I, PDGF and EGF

FEBS Letters

Manzoli, Lucia⁴  Martelli, Alberto M.³  Billi, Anna Maria⁵  Cocco, Lucio⁵  Rubbini, Silvia⁶  Neri, Luca M.¹  Gilmour, R.Stewart² 

[1] Istituto di Anatomia Umana Normale, Università di Ferrara, Ferrara, Italy;Dipartimento di Morfologia Umana Normale, Università di Trieste, Trieste, Italy;Department of Cellular Physiology, AFRC Brabham Institute, Cambridge, UK;Istituto di Morfologia Umana Normale, Università di Chieti, Chieti, Italy;Istituto di Anatomia Umana Normale, Università di Bologna, Bologna, Italy;Istituto di Citomorfologia Normale e Patologica del CNR, Chieti/Bologna (c/o IOR), Italy

关键词: Protein Kinase C;    Nucleus;    Translocation;    Confocal microscopy;    Growth factor;    PKC;    protein kinase C;    GF;    growth factor;    IGF-I;    insulin-like growth factor I;    PDGF;    platelet-derived growth factor;    EGF;    epidermal growth factor;    FGF;    fibroblast growth factor;    BSA;    bovine serum albumin;    PLC;    phospholipase C specific for inositol lipid;    DAG;    diacylglycerol;    PBS;    phosphate-buffered saline;    TRITC;    tetramethylrhodamine isothiocyanate;   

DOI  :  10.1016/0014-5793(94)00508-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

To determine the subcellular distribution of PKC after GFs treatment we have employed a combined immunochemical and in situ confocal microscopy analysis. In quiescent SvMs 3T3 cells only a faint PKC positivity was observable in the nucleus while a strong reaction was seen in the cytoplasm. IGF-I and to a lesser extent PDGF and EGF induced, after 45 min of treatment, a nuclear translocation of PKC detected by a pan-anti-PKC antibody and nuclear fluorescence was distributed in the nuclear interior except for the nucleolar regions. Bombesin and FGF did not affect the sub-cellular distribution of the enzyme. To further the understanding of which PKC isoform was involved in the transiocation process, we have tested nine isozyme-speeffic anti-PKC antibodies. Immunoblotting analysis revealed the presence in Swiss 3T3 fibroblasts of α, β_I, ε and ζ isoforms. In isolated nuclei from GF-exposed cells only the α isozyme was detected: immunostaining was very intense after IGF-I treatment and clearly observable after PDGF and EGF stimulation. This result was strongly supported by the in situ confocal microscopy which parallels the Western blot analysis. These data demonstrate that several, but not all, GFs acting through tyrosine kinase receptor induce the intranuclear translocation of PKC α and, because of the dramatic effect of IGF-I, strengthen the case for a link between the activation of nuclear inositol lipid cycle and PKC translocation induced by this GF.

【 授权许可】

Unknown