Extracellular calcium promotes internalization and degradation of the fission yeast TRP-like calcium ion channel Pkd2.

The correct localization of proteins is linked to their cellular function. The Pkd2 localizes to the endoplasmic reticulum and plasma membrane. Here we investigate the behavior of Pkd2 in response to calcium. Pkd2-GFP, normally enriched at the cell ends, is reduced from the plasma membrane by CaCl addition, while cytoplasmic dots and free GFP are increased. This suggests that Pkd2 is internalized and degraded in response to extracellular CaCl . This internalization is partially suppressed by treatment with an Arp2/3 inhibitor, CK-666. Our data provide new insights into the relationship between Pkd2 internalization and calcium response.