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.
Lee
Jiyoung
J
Division of Applied Life Science, Plant Molecular Biology and Biotechnology Research Center, Graduate School of Gyeongsang National University, Jinju, Korea.
Lee
Boyoung
B
Shin
Dongjin
D
Kwak
Sang-Soo
SS
Bahk
Jeong Dong
JD
Lim
Chae Oh
CO
Yun
Dae-Jin
DJ
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