The role of GH receptor tyrosine phosphorylation in Stat5 activation

in Journal of Molecular Endocrinology
Authors:
J A Hansen
Search for other papers by J A Hansen in
Current site
Google Scholar
PubMed
Close
,
L H Hansen
Search for other papers by L H Hansen in
Current site
Google Scholar
PubMed
Close
,
X Wang
Search for other papers by X Wang in
Current site
Google Scholar
PubMed
Close
,
J J Kopchick
Search for other papers by J J Kopchick in
Current site
Google Scholar
PubMed
Close
,
F Gouilleux
Search for other papers by F Gouilleux in
Current site
Google Scholar
PubMed
Close
,
B Groner
Search for other papers by B Groner in
Current site
Google Scholar
PubMed
Close
,
J H Nielsen
Search for other papers by J H Nielsen in
Current site
Google Scholar
PubMed
Close
,
A Møldrup
Search for other papers by A Møldrup in
Current site
Google Scholar
PubMed
Close
,
E D Galsgaard
Search for other papers by E D Galsgaard in
Current site
Google Scholar
PubMed
Close
, and
N Billestrup
Search for other papers by N Billestrup in
Current site
Google Scholar
PubMed
Close
Restricted access
Rent on DeepDyve

Sign up for journal news

ABSTRACT

Stimulation of GH receptors leads to rapid activation of Jak2 kinase and subsequent tyrosine phosphorylation of the GH receptor. Three specific tyrosines located in the C-terminal domain of the GH receptor have been identified as being involved in GH-stimulated transcription of the Spi 2·1 promoter. Mutated GH receptors lacking all but one of these three tyrosines are able to mediate a transcriptional response when transiently transfected into CHO cells together with a Spi 2·1 promoter/luciferase construct. Similarly, these GH receptors were found to be able to mediate activation of Stat5 DNA-binding activity, whereas the GH receptor mutant lacking all intracellular tyrosines was not. Synthetic tyrosine phosphorylated peptides corresponding to the GH receptor sequence around the three tyrosines inhibited Stat5 DNA-binding activity while their non-phosphorylated counterparts were ineffective. Tyrosine phosphorylated GST-GH receptor fusion proteins specifically bound to Stat5 in extracts from COS 7 cells transfected with Stat5 cDNA. This binding could be inhibited by tyrosine phosphorylated peptides derived from the GH receptor. This study thus demonstrated that specific GH receptor tyrosine residues, in their phosphorylated state, are involved in transcriptional signaling by directly interacting with Stat5.