Rck1 up-regulates Hog1 activity by down-regulating Slt2 activity in Saccharomyces cerevisiae.
We previously reported that the over-expression of KDX1 up-regulates RCK1 gene expression. To further understand the function of Rck1, microarray analysis was performed using a RCK1 over-expressing strain. Based on microarray and Northern blot analyses, we determined that the expression of KDX1 was down-regulated when RCK1 was over-expressed. Furthermore, we determined that phosphorylated forms of Slt2 and Mkk2 were down-regulated by the over-expression of RCK1. Ptp2, a phosphatase that is regulated by the Slt2 MAP kinase pathway, was down-regulated by the over-expression of RCK1. Ptp2 is a negative regulator of Hog1; thus, the phosphorylated form of Hog1 was up-regulated by RCK1 over-expression. A point mutation of lysine 152 to arginine resulted in a failure to up-regulate Hog1 and the subsequent down-regulation of CTT1, which is a Hog1 pathway target gene. Furthermore, using microarray and Northern blot analyses, we determined that genes that are regulated by Msn2/Msn4 were up-regulated by Rck1 and that this was the result of Hog1 activation by RCK1 over-expression. Together, our results suggest that Rck1 inhibits Slt2 MAP kinase pathway activity and then Ptp2, which subsequently activates Hog1.
School of Life Sciences and Biotechnology, Korea University, Anam-dong, Sungbuk-gu, Seoul, Republic of Korea.
Miwha
M
Chang
Hyun-Jun
HJ
Kang
In-Joon
IJ
Baek
Chang-Min
CM
Kang
Yong-Sung
YS
Park
Cheol-Won
CW
Yun
D015966:Gene Expression Regulation, Fungal; D020935:MAP Kinase Signaling System; D020929:Mitogen-Activated Protein Kinase Kinases / Q000235:genetics / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics* / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D017354:Point Mutation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000378:metabolism; D017027:Protein Tyrosine Phosphatases / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism
C080988:MLP1 protein, S cerevisiae; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; D017346:Protein Serine-Threonine Kinases; C407463:RCK1 protein, S cerevisiae; C088589:HOG1 protein, S cerevisiae; D020928:Mitogen-Activated Protein Kinases; C072724:SLT2 protein, S cerevisiae; C561307:MKK2 protein, S cerevisiae; D020929:Mitogen-Activated Protein Kinase Kinases; D017027:Protein Tyrosine Phosphatases; C528257:Ptp2 protein, S cerevisiae
Kdx1; Mkk2; Rck1; Saccharomyces cerevisiae; Slt2