Purification and characterisation of p99, a nuclear modulator of protein phosphatase 1 activity
Purification and characterisation of p99, a nuclear modulator of protein phosphatase 1 activity
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DOI：
10.1016/s0014-5793(97)01485-3
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发表时间：
1997-12-22
期刊：
影响因子：
3.5
通讯作者：
Lamond, AI
中科院分区：
文献类型：
--
作者：
Kreivi, JP;Trinkle-Mulcahy, L;Lamond, AI
我们从HeLa细胞核中纯化了一种蛋白磷酸酶1（PP 1），它与一个称为p99的调节亚基复合。我们在此报告了p99组分的克隆和鉴定，p99 mRNA在人体组织中广泛表达，抗p99抗体的免疫荧光分析显示核质染色呈点状，并在核仁中有额外的积累，p99的C-末端含有7个RGG RNA结合基序，随后是11个含有6个或更多个以下保守残基（GHRPHEGPGG）的十肽重复序列，最后是一个推定的锌指结构域。重组p99抑制PP 1的磷酸化酶磷酸酶活性> 90%，并且p99上的典型PP 1结合基序（残基396-401）是不寻常的，因为苯丙氨酸残基被色氨酸取代。(C)1997年欧洲生物化学学会联合会。
We have purified a form of protein phosphatase 1 (PP1) from HeLa cell nuclei, in which the phosphatase is complexed to a regulatory subunit termed p99, We report here the cloning and characterisation of the p99 component, p99 mRNA is widely expressed in human tissues and immunofluorescence analysis with anti-p99 antibodies showed a punctate nucleoplasmic staining with additional accumulations within the nucleolus, The C-terminus of p99 contains seven RGG RNA-binding motifs, followed by eleven decapeptide repeats containing six or more of the following conserved residues (GHRPHEGPGG), and finally a putative zinc finger domain. Recombinant p99 suppresses the phosphorylase phosphatase activity of PP1 by > 90% and the canonical PP1-binding motif on p99 (residues 396-401) is unusual in that the phenylalanine residue is replaced by tryptophan. (C) 1997 Federation of European Biochemical Societies.