NCBI Summary:
This gene encodes a cytoplasmic protein which contains a regulation of G-protein signaling (RGS) domain and a dishevelled and axin (DIX) domain. The encoded protein interacts with adenomatosis polyposis coli, catenin (cadherin-associated protein), beta 1, 88kDa, glycogen synthase kinase 3 beta, protein phosphate 2, and itself. This protein functions as a negative regulator of the wingless-type MMTV integration site family, member 1 (WNT) signaling pathway and can induce apoptosis. The crystal structure of a portion of this protein, alone and in a complex with other proteins, has been resolved. Mutations in this gene have been associated with hepatocellular carcinoma, hepatoblastomas, ovarian endometriod adenocarcinomas, and medullablastomas. Two transcript variants encoding distinct isoforms have been identified for this gene. [provided by RefSeq]
General function
Intracellular signaling cascade
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Cellular localization
Cytoplasmic
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Ovarian function
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Expression regulated by
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Ovarian localization
Cumulus
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Identification of WNT/{beta}-CATENIN signaling pathway components in human cumulus cells. Wang HX et al. Signaling via the conserved WNT/beta-CATENIN pathway controls diverse developmental processes. To explore its potential role in the ovary, we investigated the expression of WNTs, frizzled (FZD) receptors, and other pathway components in human cumulus cells obtained from oocytes collected for in vitro fertilization. Proteins were detected in cultured cells using immunofluorescence microscopy. Protein-protein interactions were analyzed by means of immunoprecipitation. WNT2, FZD2, FZD3, and FZD9 were identified but WNT1, WNT4 and FZD4 were not detected. WNT2 is co-expressed with FZD2, FZD3, and FZD9. Co-immunoprecipitation using WNT2 antibody demonstrated that WNT2 interacts with both FZD3 and FZD9, but only FZD9 antibody precipitated WNT2. We also identified DVL (disheveled), AXIN, GSK-3beta (glycogen synthase kinase-3beta), and beta-CATENIN. beta-CATENIN is concentrated in the plasma membranes. DVL co-localizes with FZD9 and AXIN in the membranes, but GSK-3beta has little colocalization with AXIN and beta-CATENIN. Interestingly, beta-CATENIN is highly co-localized with FZD9 and AXIN. CDH1 (E-cadherin) was also detected in the plasma membranes and cytoplasm, co-localized with beta-CATENIN, and CDH1 antibody precipitated beta-CATENIN. The results suggest that WNT2 could act through its receptor FZD9 to regulate the beta-CATENIN pathway in cumulus cells, recruiting beta-CATENIN into plasma membranes and promoting the formation of adherens junctions involving CDH1.