PTP-S2, a nuclear tyrosine phosphatase, is phosphorylated and excluded from condensed chromosomes during mitosis

Journal of biosciences

Shubhangi Kamatkar¹  Sundaram Nambirajan¹  Vegesna Radha¹  Ghanshyam Swarup1¹ 

[1] Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India$$

关键词: Cell division;    CK2;    mitosis;    mitosis specific phosphorylation;    nuclear tyrosine phosphatase;    PTP-S2;   

DOI  :  

来源: Indian Academy of Sciences

【 摘 要 】

PTP-S2 is a tyrosine specific protein phosphatase that binds to DNA and is localized to the nucleus in association with chromatin. It plays a role in the regulation of cell proliferation. Here we show that the subcellular distribution of this protein changes during cell division. While PTP-S2 was localized exclusively to the nucleus in interphase cells, during metaphase and anaphase it was distributed throughout the cytoplasm and excluded from condensed chromosomes. At telophase PTP-S2 began to associate with chromosomes and at cytokinesis it was associated with chromatin in the newly formed nucleus. It was hyperphosphorylated and showed retarded mobility in cells arrested in metaphase. In vitro experiments showed that it was phosphorylated by CK2 resulting in mobility shift. Using a deletion mutant we found that CK2 phosphorylated PTP-S2 in the C-terminal non-catalytic domain. A heparin sensitive kinase from mitotic cell extracts phosphorylated PTP-S2 resulting in mobility shift. These results are consistent with the suggestion that during metaphase PTP-S2 is phosphorylated (possibly by CK2 or a CK2-like enzyme), resulting in its dissociation from chromatin.

【 授权许可】

Unknown