Meta-Biol

• Pathways

GH stimulated tyrosyl phosphorylation of Stats 1, 3, and 5 in CHO cells expressing GHR constructs that bind JAK2 but not in CHO cells expressing GHR constructs that do not bind JAK2 (Smit et al. 1996). STAT5 phosphorylation was greatly reduced in GHR mutants with the distal region of the cytoplasmic tail removed and by mutation of distal GHR tyrosine residues to phenylalanine but this had no effect on STAT1/STAT3 phosphorylation, suggesting that the latter interact with JAK2 directly.