Identification of a plasma membrane protein involved in Pi transport in the yeast Candida tropicalis.

A plasma membrane protein was found to contain antigenic determinants in common with a Pi-binding protein released by osmotic shock from Candida tropicalis. This plasma membrane protein (M.P. 30) has a molecular mass of 30 kDa as measured by SDS-PAGE and anti-M.P. 30 antibodies inhibit Pi uptake in protoplasts while only the corresponding Fab fragments inhibit Pi transport in whole cells. This plasma membrane protein may be the Pi plasma membrane carrier.