PP1gamma2 and PPP1R11 are parts of a multimeric complex in developing testicular germ cells in which their steady state levels are reciprocally related.
PP1gamma2 and PPP1R11 are parts of a multimeric complex in developing testicular germ cells in which their steady state levels are reciprocally related.
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DOI：
10.1371/journal.pone.0004861
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发表时间：
2009
期刊：
影响因子：
3.7
通讯作者：
Vijayaraghavan S
中科院分区：
文献类型：
--
作者：
Cheng L;Pilder S;Nairn AC;Ramdas S;Vijayaraghavan S
缺乏蛋白磷酸酶1 γ亚型PP 1 γ1和PP 1 γ2的小鼠由于生殖细胞形态发生和细胞凋亡缺陷而雄性不育。然而，这种缺陷不会引起其他组织的明显异常。采用生物化学方法来了解PP 1 γ2（雄性生殖细胞中主要的PP 1亚型）的表达与缺乏如何影响精子发生。本研究中使用的方法包括柱层析、蛋白质印迹和北方印迹分析、GST下拉测定、免疫沉淀、非变性凝胶电泳、磷酸酶酶测定、蛋白质测序和免疫组织化学。我们首次报道了在野生型睾丸中，PP 1 γ2与肌动蛋白、蛋白磷酸酶1调节亚基7（PPP 1 R7）和蛋白磷酸酶1调节亚基11（PPP 1 R11）形成无活性复合物，后者是一种有效的PP 1抑制剂。有趣的是，PPP 1 R11蛋白，而不是其mRNA水平，福尔斯显着下降，在PP 1 γ-null睾丸中，成熟精子几乎是不存在的。相反，在表达转基因PP 1 γ2的PP 1 γ-null睾丸中，成熟精子数量和PPP 1 R11水平均显著增加。PPP 1 R11在PP 1 γ缺失的睾丸中也被泛素化。在表型正常的PP 1 α缺失的睾丸中，PP 1 γ2和PPP 1 R11的水平升高。然而，在PP 1 α-null脾中，PP 1 γ2通常不表达，PPP 1 R11水平保持不变。我们的数据清楚地显示了蛋白磷酸酶亚型PP 1 γ2及其调节因子PPP 1 R11的水平之间的直接相互关系，并表明睾丸中这些多肽之间的复合物形成可能阻止PPP 1 R11的蛋白水解，从而阻止生殖细胞凋亡。
Mice lacking the protein phosphatase 1 gamma isoforms, PP1γ1 and PP1γ2, are male-sterile due to defective germ cell morphogenesis and apoptosis. However, this deficiency causes no obvious abnormality in other tissues. A biochemical approach was employed to learn how expression versus deficiency of PP1γ2, the predominant PP1 isoform in male germ cells, affects spermatogenesis. Methods used in this study include column chromatography, western blot and northern blot analyses, GST pull-down assays, immunoprecipitation, non-denaturing gel electrophoresis, phosphatase enzyme assays, protein sequencing, and immunohistochemistry. We report for the first time that in wild-type testis, PP1γ2 forms an inactive complex with actin, protein phosphatase 1 regulatory subunit 7 (PPP1R7), and protein phosphatase 1 regulatory subunit 11 (PPP1R11), the latter, a potent PP1 inhibitor. Interestingly, PPP1R11 protein, but not its mRNA level, falls significantly in PP1γ-null testis where mature sperm are virtually absent. Conversely, both mature sperm numbers and the PPP1R11 level increase substantially in PP1γ-null testis expressing transgenic PP1γ2. PPP1R11 also appears to be ubiquitinated in PP1γ-null testis. The levels of PP1γ2 and PPP1R11 were increased in phenotypically normal PP1α-null testis. However, in PP1α-null spleen, where PP1γ2 normally is not expressed, PPP1R11 levels remained unchanged. Our data clearly show a direct reciprocal relationship between the levels of the protein phosphatase isoform PP1γ2 and its regulator PPP1R11, and suggest that complex formation between these polypeptides in testis may prevent proteolysis of PPP1R11 and thus, germ cell apoptosis.
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影响因子：
3.6
作者：
Huang, ZH;Somanath, PR;Vijayaraghavan, S
通讯作者：
Vijayaraghavan, S
影响因子：
3.6
作者：
Bajpai, M;Fiedler, SE;Carr, DW
通讯作者：
Carr, DW
DOI：
10.1046/j.1432-1327.1999.00344.x
发表时间：
1999-05-01
期刊：
EUROPEAN JOURNAL OF BIOCHEMISTRY
影响因子：
--
作者：
Ceulemans, H;Van Eynde, A;Bollen, M
通讯作者：
Bollen, M
影响因子：
2.9
作者：
Chakrabarti, Rumela;Cheng, Lina;Vijayaraghavan, Srinivasan
通讯作者：
Vijayaraghavan, Srinivasan
影响因子：
3.9
作者：
Cohen, Philip;Nimmo, Gillian A.
通讯作者：
Nimmo, Gillian A.