Carnitine uptake by AGP2 in yeast Saccharomyces cerevisiae is dependent on Hog1 MAP kinase pathway.
The AGP2 gene encodes a plasma membrane carnitine transporter in S. cerevisiae. Here, we report the identification of AGP2 as an osmotic stress response gene. AGP2 was isolated from mTn3 tagged mutants that contained in-frame fusions with lacZ. The expression of AGP2 was down-regulated by osmotic stresses, including NaCl, sorbitol, and KCI. We also found that carnitine uptake was inhibited by NaCl. In the ssk1delta stelldelta double-mutant strain, the expression of AGP2 and the uptake of carnitine were greatly reduced compared to the wild-type strain. Furthermore, carnitine uptake was inhibited by the constitutive expression of PBS2, which encodes a MAPKK that activates Hog1. We concluded, therefore, that the HOG pathway plays an important role in the regulation of carnitine uptake in S. cerevisiae.
Division of Applied Life Science, Plant Molecular Biology and Biotechnology Research Center, Graduate School of Gyeongsang National University, Jinju, Korea.
Jiyoung
J
Lee
Boyoung
B
Lee
Dongjin
D
Shin
Sang-Soo
SS
Kwak
Jeong Dong
JD
Bahk
Chae Oh
CO
Lim
Dae-Jin
DJ
Yun
D026905:Amino Acid Transport Systems / Q000037:antagonists & inhibitors / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002331:Carnitine / Q000037:antagonists & inhibitors* / Q000493:pharmacokinetics*; D015536:Down-Regulation / Q000187:drug effects; D020929:Mitogen-Activated Protein Kinase Kinases / Q000494:pharmacology; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism / Q000502:physiology*; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism* / Q000502:physiology*; D012965:Sodium Chloride / Q000494:pharmacology; D027981:Symporters / Q000037:antagonists & inhibitors / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
C402286:Agp2 protein, S cerevisiae; D026905:Amino Acid Transport Systems; D029701:Saccharomyces cerevisiae Proteins; D027981:Symporters; D012965:Sodium Chloride; C088589:HOG1 protein, S cerevisiae; D020928:Mitogen-Activated Protein Kinases; D020929:Mitogen-Activated Protein Kinase Kinases; C089356:PBS2 protein, S cerevisiae; D002331:Carnitine