The N-terminal domain of yeast Bap2 permease is phosphorylated dependently on the Npr1 kinase in response to starvation.
The Saccharomyces cerevisiae branched-chain amino acid permease Bap2p plays a major role in leucine, isoleucine, and valine transport, and its synthesis is regulated transcriptionally. Bap2p undergoes a starvation-induced degradation depending upon ubiquitination and the functions of N- and C-terminal domains of Bap2p. Here we show that the N-terminal domain of Bap2p is phosphorylated in response to rapamycin treatment when both the N- and C-termini of Bap2p are fused to glutathione S-transferase. The phosphorylation is dependent on Ser/Thr kinase Npr1p. In npr1 cells, Bap2p becomes slightly more susceptible to the rapamycin-induced degradation, suggesting that Npr1p counteracts the degradation system for Bap2p.
Omura
Fumihiko
F
Institute for Beer and RTD Development, Suntory Limited, 1-1-1, Wakayamadai, Shimamoto-cho, Mishima-gun, Osaka 618-8503, Japan. fumihiko_omura@suntory.co.jp
Kodama
Yukiko
Y
D026905:Amino Acid Transport Systems / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000935:Antifungal Agents / Q000494:pharmacology; D003470:Culture Media; D015966:Gene Expression Regulation, Fungal; D010766:Phosphorylation; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020123:Sirolimus / Q000494:pharmacology
D026905:Amino Acid Transport Systems; D000935:Antifungal Agents; C097094:BAP2 protein, S cerevisiae; D003470:Culture Media; D029701:Saccharomyces cerevisiae Proteins; C066958:NPR1 protein, S cerevisiae; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D020123:Sirolimus