JAK2 binds STAT1/3

JAK2 is believed to bind STAT1 and STAT3 directly in response to GH, as opposed to STAT5 which binds to phosphorylated tyrosine residues in the distal portion of the GHR cytoplasmic region (Smit et al. 1996). When associated with the prolactin receptor JAK2 is able to bind STAT1, STAT3 and STAT5 (DaSilva et al. 1996).

Smit et al. identified mouse GHR residues Y341 (human Y332) and Y346 (not conserved in human) as required for STAT1, 3, and maximal STAT5 activation.

据信JAK2能够在响应GH信号时直接与STAT1和STAT3结合，这与STAT5结合GHR细胞质区域远端磷酸化酪氨酸残基的情况形成对比（Smit等，1996年）。当与催乳素受体相结合时，JAK2能够与STAT1、STAT3和STAT5结合（DaSilva等，1996年）。Smit等（1996年）确定了小鼠GHR的Y341（人类为Y332）和Y346（在人类中不保守）残基是STAT1、3以及STAT5最大激活所必需的。