Open AccessThe N‐terminal domain of yeast Bap2 permease is phosphorylated dependently on the Npr1 kinase in response to starvation
Author(s) -
Omura Fumihiko,
Kodama Yukiko
Publication year - 2004
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1016/s0378-1097(03)00918-2
Subject(s) - biochemistry , permease , phosphorylation , yeast , saccharomyces cerevisiae , kinase , biology , leucine , valine , amino acid , microbiology and biotechnology , transporter , gene
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.