NCBI Summary:
The protein encoded by this gene is a member of the S100 family of proteins containing 2 EF-hand calcium-binding motifs. S100 proteins are localized in the cytoplasm and/or nucleus of a wide range of cells, and involved in the regulation of a number of cellular processes such as cell cycle progression and differentiation. S100 genes include at least 13 members which are located as a cluster on chromosome 1q21. This protein may function in motility, invasion, and tubulin polymerization. Chromosomal rearrangements and altered expression of this gene have been implicated in tumor metastasis. [provided by RefSeq]
General function
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Cellular localization
Cytoplasmic, Nuclear
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Ovarian function
Early embryo development
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Immunohistochemical Characterization of S100A6 in the Murine Ovary. Hanaue M et al. S100 proteins comprise a large family of Ca(2+)-binding proteins and exhibit a variety of intra- and extracellular functions. Despite our growing knowledge about the biology of S100 proteins in some tissues such as brain and smooth muscle, little is known about S100 proteins in the normal mammalian reproductive tissue. In the present study, we investigated the distribution pattern of S100A6 (alternatively named calcyclin) in the murine ovary by immunohistochemical study using specific antibody. S100A6 was localized substantially in the cytoplasm of luteal cells, with concomitant expression of S100A11, another S100 protein, but not in the other type of cells such as oocytes, follicle epithelial cells (granulosa cells), and cells of stroma including theca interna cells in the murine ovary. S100A6-immunoreactive corpora lutea (CLs) were divided into two types: homogeneously and heterogeneously stained CLs, and possibly they may represent differentiating and mature CL, respectively. Our regression analysis revealed that expression level of S100A6 positively correlated with that of cytochrome P450 11A, a steroidogenic enzyme in the heterogeously stained CL. These results suggested that S100A6 may contribute to differentiation of steroidogenic activity of luteal cells in a synergistic manner with S100A11 by facilitating some shared functions.
Expression regulated by
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Ovarian localization
Luteal cells
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Characterization of S100A11, a suppressive factor of fertilization, in the mouse female reproductive tract. Hanaue M et al. We recently found that Xenopus dicalcin, present in the extracellular egg-coating envelope, suppresses the efficiency of fertilization in vitro through binding to envelope-constituent glycoproteins. In the present study, we explored the mouse counterpart of Xenopus dicalcin, specifically its localization in the female reproductive tract and its action on mouse fertilization. Our homology and phylogenetic analyses using known S100 proteins showed that S100A11 is most closely related to Xenopus dicalcin. S100A11 was localized in the cytosol of luteal cells, but not in the follicle, in the mouse ovary, and also in the cytosol of the oviductal epithelial cells. In addition, our quantitative analyses revealed preferential expression of S100A11 in the ampullary region of the oviduct and at the estrus stage during the mouse estrous cycle. In the cumulus cell-oocyte complex dissected from the oviduct following ovulation, S100A11 was present in the plasma membrane of cumulus cells, but not in the zona pellucida, which is comparable with Ca(2+) -dependent binding of exogenously applied S100A11 to the plasma membrane of cumulus cells. Pretreatment of the cumulus cell-oocyte complex with recombinant S100A11 substantially reduced the efficiency of in vitro fertilization, but S100A10, the next closest S100 protein to Xenopus dicalcin, had no effect. These results suggested that S100A11 is the mouse counterpart of Xenopus dicalcin, suppresses the fertilization process through its action on cumulus cells, and thereby plays a key role in fertilization success in the mouse. Mol. Reprod. Dev. ? 2011 Wiley-Liss, Inc.