Overexpression of Trpp5 contributes to cell proliferation and apoptosis probably through involving calcium homeostasis.

Trpp5 is one member of the polycystic kidney disease (PKD) family, which belongs to transient receptor potential (TRP) superfamily. Our previous study has shown that Trpp5 is developmentally expressed in mouse testis and overexpression of Trpp5 increases intracellular free calcium concentration in MDCK cells. However, the roles of this protein in cellular processes are largely unknown. Here, we demonstrated that Trpp5 resided in both cytoplasm and cell membrane of HEK293 cells. We found that overexpression of Trpp5 slightly increased the calcium current amplitude of HEK293 cells and shifted the reversal potential to a more negative value. Meanwhile, overexpression of Trpp5 suppressed proliferation of Hela cells via inhibiting DNA replication and induced apoptosis of Hela cells with morphological changes and accumulation of fragmented DNA. Collectively, these findings suggest that Trpp5 might involve calcium homeostasis contributing to cell proliferation and apoptosis.