Vital cellular functions such as cell proliferation and signal transduction are regulated in part by the balance between the activities of protein-tyrosine kinases (PTK) and protein-tyrosine phosphatases (PTPase). Oncogenesis can result from an imbalance. There are 2 classes of PTPase molecules: low molecular weight proteins with a single conserved phosphatase domain such as T-cell protein-tyrosine phosphatase (PTPT; 176887), and high molecular weight receptor-linked PTPases with 2 tandemly repeated conserved domains separated by 56 to 57 amino acids.
NCBI Summary:
The protein encoded by this gene is a member of the protein tyrosine phosphatase (PTP) family. PTPs are known to be signaling molecules that regulate a variety of cellular processes including cell growth, differentiation, mitotic cycle, and oncogenic transformation. This PTP possesses an extracellular region, a single transmembrane region, and two tandem catalytic domains, and thus represents a receptor-type PTP. The extracellular region contains a meprin-A5 antigen-PTP mu (MAM) domain, an Ig-like domain and four fibronectin type III-like repeats. This PTP was shown to mediate homophilic intercellular interaction, possibly through the interaction with beta- and gamma-catenin at adherens junctions. Expression of this gene was found to be stimulated by TGF-beta 1, which may be important for the inhibition of keratinocyte proliferation. [provided by RefSeq, Jul 2008]
ZP3 is Required for Germinal Vesicle Breakdown in Mouse Oocyte Meiosis. Gao LL et al. (2017) ZP3 is a principal component of the zona pellucida (ZP) of mammalian oocytes and is essential for normal fertility, and knockout of ZP3 causes complete infertility. ZP3 promotes fertilization by recognizing sperm binding and activating the acrosome reaction; however, additional cellular roles for ZP3 in mammalian oocytes have not been yet reported. In the current study, we found that ZP3 was strongly expressed in the nucleus during prophase and gradually translocated to the ZP. Knockdown of ZP3 by a specific siRNA dramatically inhibited germinal vesicle breakdown (GVBD) (marking the beginning of meiosis), significantly reducing the percentage of MII oocytes. To investigate the ZP3-mediated mechanisms governing GVBD, we identified potential ZP3-interacting proteins by immunoprecipitation and mass spectrometry. We identified Protein tyrosine phosphatase, receptor type K (Ptprk), Aryl hydrocarbon receptor-interacting protein-like 1 (Aipl1), and Diaphanous related formin 2 (Diaph2) as potential candidates, and established a working model to explain how ZP3 affects GVBD. Finally, we provided preliminary evidence that ZP3 regulates Akt phosphorylation, lamin binding to the nuclear membrane via Aipl1, and organization of the actin cytoskeleton via Diaph2. These findings contribute to our understanding of a novel role played by ZP3 in GVBD.//////////////////
Expression regulated by
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Ovarian localization
Oocyte, Granulosa
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Shiota M, et al (2003) reported that Protein Tyrosine Phosphatase PTP20 Induces Actin Cytoskeleton Reorganization by Dephosphorylating p190 RhoGAP in Rat Ovarian Granulosa Cells Stimulated with Follicle-Stimulating Hormone.
The authors identified 25 protein tyrosine phosphatases (PTPs) expressed in rat ovarian granulosa cells.