Downregulation of protein kinase C‐γ is independent of a functional kinase domain

FEBS Letters

Freisewinkel, Ina¹  Riethmacher, Dieter¹  Stabel, Silvia¹ 

[1]Max-Delbrück-Labor in der Max-Planck-Gesellschaft, Carl-von-Linné-Weg 10, D-5000 Köln 30, Germany

关键词: Protein kinase C;    Downregulation;    Baculovirus expression;    Kinase-deficient mutant;    Phorbol ester;   

DOI  :  10.1016/0014-5793(91)80307-O

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Prolonged activation of protein kinase C (PKC) types α and β by tumor-promoting phorbol esters leads to desensitization of the phorbol ester response, downregulation of protein kinase C activity and depletion of the protein kinase C polypeptide. When the γ isoenzyme of PKC is transiently expressed in COS-1 cells and exposed to phorbol esters, PKC-γ is downregulated in COS cells although these cells do not normally express this subtype. A point mutation in the purative ATP-binding site (Lys-380→Met-380) of the protein kinase C γ isoenzyme which results in a kinase-deficient enzyme does not interfere with this downregulation. Our results suggest that autophosphorylation or constitutive signalling through the protein kinase C-γ kinase domain is not a prerequisite for downregulation of PKC activity.

【 授权许可】

Unknown