Regulation of Yeast Nutrient Permease Endocytosis by ATP-binding Cassette Transporters and a Seven-transmembrane Protein, RSB1

摘要: Ceramide is produced by the condensation of a long chain base with very fatty acid. In Saccharomyces cerevisiae, one two major bases called phytosphingosine (PHS). PHS has been shown to cause toxicity in tryptophan auxotrophic strains yeast because this bioactive ceramide precursor causes diversion high affinity permease Tat2 vacuole rather than plasma membrane. Loss integral membrane protein Rsb1 increased sensitivity, which was suggested be due acting as an ATP-dependent efflux protein. More recent experiments demonstrated that loss genes encoding ATP-binding cassette transporter proteins Pdr5 and Yor1 elevated tolerance. This resistance expression RSB1. Here, we provide alternative view influenced Pdr5/Yor1. seven-transmembrane domain topology more consistent regulatory like G-protein-coupled receptor transporter. Importantly, rsb1Δ cell does not exhibit higher internal levels compared isogenic wild-type cells. However, transport pdr5Δ yor1 reduced Localization vacuolar degradation are affected these genetic backgrounds. Finally, internalization FM4-64 dye suggests slows normal endocytic rates. Together, data argue Rsb1, Pdr5, regulate endocytosis likely other proteins.