Ptpcd-1 is a novel cell cycle related phosphatase that regulates centriole duplication and cytokinesis

Department of Cell Biology and Biochemistry, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan.
Biochemical and Biophysical Research Communications (Impact Factor: 2.3). 04/2009; 380(3):460-6. DOI: 10.1016/j.bbrc.2009.01.113
Source: PubMed


Proper progression of mitosis requires spatio-temporal regulation of protein phosphorylation by orchestrated activities of kinases and phosphatases. Although many kinases, such as Aurora kinases, polo-like kinases (Plks), and cyclin B-Cdk1 are relatively well characterized in the context of their physiological functions at mitosis and regulation of their enzymatic activities during mitotic progression, phosphatases involved are largely unknown. Here we identified a novel protein tyrosine phosphatase containing domain 1 (Ptpcd 1) as a mitotic phosphatase, which shares sequence homology to Cdc14. Immunofluorescence studies revealed that Ptpcd1 partially colocalized with gamma-tubulin, an archetypical centrosomal marker. Overexpression of this phosphatase prevented unscheduled centrosomal amplification in hydroxyurea arrested U2OS cells. Intriguingly, Ptpcd 1-associated and colocalized with polo-like kinase 1(Plk1). Hence, overexpression of Ptpcd1 rescued prometaphase arrest of Plk-1 depleted cells, but resulted in aberrant cytokinesis as did as Plk1 overexpression. These results suggested that Ptpcd1 is involved in centrosomal duplication and cytokinesis.

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    • "Sequence analysis of Ptpcd2 revealed that it possessed PTP and DSP catalytic domains. Its carboxyl terminal lacks the unique coiled coil domain of Ptpcd1(Zineldeen et al., 2009), however it contains PDZ binding domain (Beuming et al., 2005). RXXL motif (APC/C binding motif), STAT5 Src Homology 2 (SH2) domains, nuclear export signals, and bipartite nuclear localizing signal were also found (Figure 1A, B). "
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