TY - JOUR

T1 - Mutation of the SHP-2 binding site in growth hormone (GH) receptor prolongs GH-promoted tyrosyl phosphorylation of GH receptor, JAK2, and STAT5B

AU - Stofega, M R

AU - Herrington, J

AU - Billestrup, Nils

AU - Carter-Su, C

PY - 2000/9

Y1 - 2000/9

N2 - Binding of GH to GH receptor (GHR) rapidly and transiently activates multiple signal transduction pathways that contribute to the growth-promoting and metabolic effects of GH. While the events that initiate GH signal transduction, such as activation of the Janus tyrosine kinase JAK2, are beginning to be understood, the signaling events that terminate GH signaling, such as dephosphorylation of tyrosyl-phosphorylated signaling molecules, are poorly understood. In this report, we examine the role of the SH2 (Src homology-2) domain-containing protein tyrosine phosphatase SHP-2 in GH signaling. We demonstrate that the SH2 domains of SHP-2 bind directly to tyrosyl phosphorylated GHR from GH-treated cells. Tyrosine-to-phenylalanine mutation of tyrosine 595 of rat GHR greatly diminishes association of the SH2 domains of SHP-2 with GHR, and tyrosine-to-phenylalanine mutation of tyrosine 487 partially reduces association of the SH2 domains of SHP-2 with GHR. Mutation of tyrosine 595 dramatically prolongs the duration of tyrosyl phosphorylation of the signal transducer and activator of transcription STAT5B in response to GH, while mutation of tyrosine 487 moderately prolongs the duration of STAT5B tyrosyl phosphorylation. Consistent with the effects on STAT5B phosphorylation, tyrosine-to-phenylalanine mutation of tyrosine 595 prolongs the duration of tyrosyl phosphorylation of GHR and JAK2. These data suggest that tyrosine 595 is a major site of interaction of GHR with SHP-2, and that GHR-bound SHP-2 negatively regulates GHR/JAK2 and STAT5B signaling.

AB - Binding of GH to GH receptor (GHR) rapidly and transiently activates multiple signal transduction pathways that contribute to the growth-promoting and metabolic effects of GH. While the events that initiate GH signal transduction, such as activation of the Janus tyrosine kinase JAK2, are beginning to be understood, the signaling events that terminate GH signaling, such as dephosphorylation of tyrosyl-phosphorylated signaling molecules, are poorly understood. In this report, we examine the role of the SH2 (Src homology-2) domain-containing protein tyrosine phosphatase SHP-2 in GH signaling. We demonstrate that the SH2 domains of SHP-2 bind directly to tyrosyl phosphorylated GHR from GH-treated cells. Tyrosine-to-phenylalanine mutation of tyrosine 595 of rat GHR greatly diminishes association of the SH2 domains of SHP-2 with GHR, and tyrosine-to-phenylalanine mutation of tyrosine 487 partially reduces association of the SH2 domains of SHP-2 with GHR. Mutation of tyrosine 595 dramatically prolongs the duration of tyrosyl phosphorylation of the signal transducer and activator of transcription STAT5B in response to GH, while mutation of tyrosine 487 moderately prolongs the duration of STAT5B tyrosyl phosphorylation. Consistent with the effects on STAT5B phosphorylation, tyrosine-to-phenylalanine mutation of tyrosine 595 prolongs the duration of tyrosyl phosphorylation of GHR and JAK2. These data suggest that tyrosine 595 is a major site of interaction of GHR with SHP-2, and that GHR-bound SHP-2 negatively regulates GHR/JAK2 and STAT5B signaling.

KW - 3T3 Cells

KW - Amino Acid Substitution

KW - Animals

KW - Binding Sites

KW - DNA-Binding Proteins

KW - Human Growth Hormone

KW - Humans

KW - Janus Kinase 2

KW - Kinetics

KW - Mice

KW - Milk Proteins

KW - Mutagenesis, Site-Directed

KW - Phenylalanine

KW - Phosphotyrosine

KW - Protein-Tyrosine Kinases

KW - Proto-Oncogene Proteins

KW - Rats

KW - Receptors, Somatotropin

KW - Recombinant Proteins

KW - STAT5 Transcription Factor

KW - Signal Transduction

KW - Trans-Activators

KW - Tyrosine

KW - src Homology Domains

U2 - 10.1210/mend.14.9.0513

DO - 10.1210/mend.14.9.0513

M3 - Journal article

C2 - 10976913

VL - 14

SP - 1338

EP - 1350

JO - Molecular Endocrinology

JF - Molecular Endocrinology

SN - 0888-8809

IS - 9

ER -