Growth hormone preferentially induces the rapid, transient expression of SOCS-3, a novel inhibitor of cytokine receptor signaling

Abstract

Four members (SOCS-1, SOCS-2, SOCS-3, and CIS) of a family of cytokine- inducible, negative regulators of cytokine receptor signaling have recently been identified. To address whether any of these genes are induced in response to growth hormone (GH), serum-starved 3T3-F442A fibroblasts were incubated with GH for various time points, and the expression of the SOCS gene family was analyzed by Northern blotting. GH stimulated the rapid, transient induction of SOCS-3 mRNA, peaking 30 rain after the initiation of GH exposure and declining to basal levels by 2 h. Expression of the other SOCS genes (SOCS-1, SOCS-2, CIS) was also up-regulated by GH, although to a lesser extent than SOCS-3 and with d..