Phosphatidylinositol transfer protein function in the yeast Saccharomyces cerevisiae

摘要

PITPs are operationally defined by in vitro assays that record the transfer Ptdlnsor PtdCho monomers between membrane bilayers (Cleves et al., 1991a; Kearns etal., 1998a; Wirtz, 1991). The specific nature of PITP physiological functions, andmechanisms that underlay such functions, remain open questions. Clear evidence tothe effect that functional analyses of PITPs will prove of broad biomedical interest isevident from recent functional studies in mammalian systems. Mammals express atleast three soluble mammalian PITPs designated PITPoc, PITP/3 and rdgB/3(Dickeson et al., 1989; Tanaka and Hosaka, 1994; Fullwood et al., 1999). Thepaucity of research activity surrounding these proteins notwithstanding, it is alreadyestablished that PITP insufficiencies lead to dramatic neurodegenerative, malabsorp-tion and glucose homeostatic defects in flies and mice (Hamilton et al., 1997;Milligan et al., 1997; Alb et al., 2003). As PITPs (or at least obvious PITP homologs)are found in all eukaryotes examined thus far, including plants (Kearns et al., 1998b;Vincent et al., 2005), we anticipate that the biological heritage of these enigmaticproteins will prove to be a rich one.