TY - JOUR

T1 - The role of GH receptor tyrosine phosphorylation in Stat5 activation

AU - Hansen, J A

AU - Hansen, L H

AU - Wang, X

AU - Kopchick, J J

AU - Gouilleux, F

AU - Groner, B

AU - Møldrup, Annette

AU - Galsgaard, E D

AU - Nielsen, Jens Høiriis

AU - Billestrup, N

PY - 1997/6

Y1 - 1997/6

N2 - 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.

AB - 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.

KW - Amino Acid Sequence

KW - Animals

KW - Base Sequence

KW - CHO Cells

KW - COS Cells

KW - Cricetinae

KW - DNA, Complementary

KW - DNA-Binding Proteins

KW - Milk Proteins

KW - Phosphorylation

KW - Plasmids

KW - Receptors, Somatotropin

KW - Recombinant Fusion Proteins

KW - STAT5 Transcription Factor

KW - Trans-Activators

KW - Transcription, Genetic

KW - Transfection

KW - Tyrosine

M3 - Journal article

C2 - 9195475

VL - 18

SP - 213

EP - 221

JO - Journal of Molecular Endocrinology

JF - Journal of Molecular Endocrinology

SN - 0952-5041

IS - 3

ER -