PHOSPHATIDYLINOSITOL TRANSFER PROTEINS - THE LONG AND WINDING ROAD TOPHYSIOLOGICAL-FUNCTION

Phosphatidylinositol transfer proteins (PITPs) have historically been thought to help execute lipid-sorting events by transporting phospholi pid monomers between membrane bilayers. Recent data, however, indicate unanticipated roles for PITPs in the coordination and/or coupling of phospholipid metabolism with vesicle trafficking and the downregulatio n of signal-transduction reactions. We are only now beginning to appre ciate both the identities of PITP-dependent cellular reactions and the intriguing mechanisms by which PITPs execute their functions in eukar yotic cells.