P13 - Physiological function of the TRPV6 protein in placenta
TRPV6 is one of two channels in the TRP family that exhibit high selectivity to Ca2+-ions. The Trpv6 gene is mainly expressed in placenta, epididymal epithelia and exocrine glands. We have shown that TRPV6 is essential for Ca2+ homeostasis in the epididymal duct and that male mice lacking functional TRPV6 channels are hypofertile. In our project, we want to elucidate the functional role of TRPV6 channels in the placenta by studying 1. the contribution of TRPV6 to maternal/fetal Ca2+ transport, placental Ca2+ homeostasis and embryonic development and 2. the composition and function of the TRPV6 containing protein complex.
A, Modell of TRPV6; the protein was identified as a highly Ca2+ selective ion channel expressed in placenta, epididymis, exocrine pancreas and salivary glands. B, In human and mouse placenta the translation of Trpv6 initiates exclusively 5´of the annotated initiation AUG, at an ACG codon which is nevertheless decoded by methionine. Therefore full length human TRPV6 protein existing in vivo comprises an amino terminus extended by 40 amino acid residues compared to the annotated truncated TRPV6 protein. C, TRPV6 proteins are localized at the syncytiotrophoblast layer (white arrow) which is at the maternal/fetal barrier of the placenta, where all transport processes between fetus and mother occur.