Purification of protein phosphatase 4 catalytic subunit: inhibition by the antitumour drug fostriecin and other tumour suppressors and promoters

FEBS Letters

Cohen, Patricia T.W¹  Hastie, C.James¹ 

[1] Medical Research Council Protein Phosphorylation Unit, Department of Biochemistry, University of Dundee, Dundee DD1 4HN, UK

关键词: Protein phosphatase;    Centrosome;    Microtubule;    Fostriecin;    Tumor promoter;    Chromosome 16;   

DOI  :  10.1016/S0014-5793(98)00775-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Protein phosphatase 4 (PP4) is a protein serine/threonine phosphatase that predominantly localises to centrosomes and plays a role in microtubule organisation at centrosomes. Here, PP4 catalytic subunit has been purified from porcine testis to near homogeneity and a specific activity of 680 mU/mg against phosphorylase a. The antitumour drug, fostriecin, inhibits PP4 catalytic subunit (IC₅₀ 3 nM) with similar potency to PP2A catalytic subunit (IC₅₀ 1.5 nM). PP4 is also inhibited in the nanomolar range by several naturally occurring tumour promoters and toxins, with similar IC₅₀ values to those obtained for PP2A. The gene for human PP4 catalytic subunit localises to 16p11.2.

【 授权许可】

Unknown