TY - JOUR
T1 - CIS1 interacts with the Y532 of the prolactin receptor and suppresses prolactin-dependent STAT5 activation
AU - Endo, Takaho
AU - Sasaki, Atsuo
AU - Minoguchi, Mayu
AU - Joo, Akiko
AU - Yoshimura, Akihiko
N1 - Funding Information:
This work was partially supported by grants from the Ministry of Education, Science, Technology, Sports, and Culture of Japan, the Japan Health Science Foundation, the Human Frontier Science Program, the Japan Research Foundation for Clinical Pharmacology, and the Haraguchi Memorial Foundation. We thank Ms. H. Ohgusu and Ms. M. Sasaki for their excellent technical assistance, Dr. A. Gertler for donating purified PRL, and Dr. W. Doppler for providing PRL receptor cDNA.
PY - 2003/1/1
Y1 - 2003/1/1
N2 - Prolactin (PRL) interacts with a single-chain prolactin-specific receptor of the cytokine receptor superfamily. PRL triggers the activation of JAK2 kinase, which phosphorylates the PRL receptor itself, and of STAT5, a member of the family of signal transducers and activators of transcription (STAT). We have shown that the STAT5-dependent immediate early gene, CIS1 (Cytokine-Inducible SH2 domain-containing protein-1), suppresses PRL-induced STAT5 activation in vitro as well as in transgenic mice. To facilitate the study of the interactions between CIS1 and the PRL receptor, we have developed the yeast tri-hybrid system, a modification of the yeast two-hybrid system. We expressed CIS1 fused to the DNA-binding domain and PRL receptor cytoplasmic domain fused to the transcription activation domain in the presence or absence of the tyrosine kinase domain of JAK2 in yeast. CIS1 bound to the PRL receptor cytoplasmic domain in a JAK2-dependent manner. Moreover, we determined that the phosphorylated Y532 of the murine PRL receptor is the binding site for CIS1. Interestingly, Y532 has been shown to be unnecessary for STAT5 activation, although CIS1 overexpression suppressed PRL-induced STAT5 activation. These data suggest that the suppression of STAT5 activation by CIS1 is not due to a simple competition with STAT5 but rather to a modification of the receptor by CIS1 binding.
AB - Prolactin (PRL) interacts with a single-chain prolactin-specific receptor of the cytokine receptor superfamily. PRL triggers the activation of JAK2 kinase, which phosphorylates the PRL receptor itself, and of STAT5, a member of the family of signal transducers and activators of transcription (STAT). We have shown that the STAT5-dependent immediate early gene, CIS1 (Cytokine-Inducible SH2 domain-containing protein-1), suppresses PRL-induced STAT5 activation in vitro as well as in transgenic mice. To facilitate the study of the interactions between CIS1 and the PRL receptor, we have developed the yeast tri-hybrid system, a modification of the yeast two-hybrid system. We expressed CIS1 fused to the DNA-binding domain and PRL receptor cytoplasmic domain fused to the transcription activation domain in the presence or absence of the tyrosine kinase domain of JAK2 in yeast. CIS1 bound to the PRL receptor cytoplasmic domain in a JAK2-dependent manner. Moreover, we determined that the phosphorylated Y532 of the murine PRL receptor is the binding site for CIS1. Interestingly, Y532 has been shown to be unnecessary for STAT5 activation, although CIS1 overexpression suppressed PRL-induced STAT5 activation. These data suggest that the suppression of STAT5 activation by CIS1 is not due to a simple competition with STAT5 but rather to a modification of the receptor by CIS1 binding.
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U2 - 10.1093/jb/mvg004
DO - 10.1093/jb/mvg004
M3 - Article
C2 - 12761205
AN - SCOPUS:0037286739
SN - 0021-924X
VL - 133
SP - 109
EP - 113
JO - Journal of biochemistry
JF - Journal of biochemistry
IS - 1
ER -