NCBI Summary:
The protein encoded by this gene interacts with calcineurin A and inhibits calcineurin-dependent signaling pathways, possibly affecting central nervous system development. This gene is located in the minimal candidate region for the Down syndrome phenotype, and is overexpressed in the brain of Down syndrome fetuses. Chronic overexpression of this gene may lead to neurofibrillary tangles such as those associated with Alzheimer disease. Three transcript variants encoding three different isoforms have been found for this gene. [provided by RefSeq]
General function
Intracellular signaling cascade
Comment
Cellular localization
Cytoplasmic
Comment
Ovarian function
Oogenesis, Oocyte maturation
Comment
Expression regulated by
Comment
Ovarian localization
Oocyte
Comment
Calcineurin and its regulation by Sra/RCAN is required for completion of meiosis in Drosophila. Takeo S et al. Ca(2+) signaling pathways play important roles to complete meiosis from metaphase II arrest in vertebrate oocytes. However, less is known about the molecular mechanism of completion of meiosis in Drosophila females. Here, we provide direct evidence that calcineurin, a Ca(2+)/calmodulin (CaM)-dependent phosphatase, is essential for meiotic progression beyond metaphase I in Drosophila oocytes. Oocytes from germline clones lacking CanB2, a calcineurin regulatory subunit B, failed to complete meiosis after egg activation, and laid eggs exhibited a meiotic arrested anaphase I chromosome configuration. Genetic analyses suggest that calcineurin activity is regulated by Sarah (Sra), a family member of regulators of calcineurin (RCANs), through a Sra phosphorylation-dependent mechanism. Our results support a view in which the phosphorylation of Sra not only acts to relieve the inhibitory effects of Sra, but also acts to activate calcineurin, thus explaining the role of RCAN proteins as positive regulators of calcineurin.