Identification of growth hormone receptor (GHR) tyrosine residues required for GHR phosphorylation and JAK2 and STAT5 activation.

摘要: To determine whether GH receptor (GHR) cytoplasmic tyrosine residue(s) and phosphorylation are required for signal transduction, we have substituted the eight porcine (p) GHR tyrosines with phenylalanine individually or in a stepwise manner from C terminus. Conversely, were regenerated non-tyrosine-containing pGHR analog. Mutated cDNAs transfected into mouse L cells (MLCs) cell lines established. Each individual tyrosine-substituted analogs was able to activate STAT5 (signal transducer activator of transcription 5; previously termed pp95) at levels comparable those wild type pGHR. Analyses these revealed that single residue position 487, 534, 566, 627 is sufficient phosphorylation. This result suggested redundancy requirement may be employed GH-mediated transduction. Also, found residues STAT...