Prolactin, STAT activation

Cytokine receptors that couple to the JAK-STAT Pathway decode the signaling though hematopoietic cytokines (erythropoietin, thrombopoietin, colony-stimulating factors), prolactin, growth hormone, the a-, (3- and y- interferons, and a number of immunomodulatory interleukins [3], They form homodimetic or heterodimeric receptor complexes, which after ligandbinding recruit and activate isotypes of Janus kinases (JAKs). Activated JAKs in turn... 

Not all receptors may be expressed in the same cell. A case in question is the restricted, cell-specific expression of receptors for IL-2, erythropoietin, thrombo-poietin, prolactin, and growth hormone, all of which activate the same STAT. 

Various other stimuli have been shown to activate the STATs in neutrophils. Amongst them, prolactin was shown to promote the tyrosine phosphorylation of STATl, and to induce the formation of a specific GAS-binding complex in EMSA [63]. The nature of the complex remains uncertain, as supershift assays were inconclusive a probable reason for this outcome is that neutrophil extracts were prepared using a detergent-based kit [63]. Nevertheless, prolactin rapidly induced the expression of SOCS-2 and IRF-1 in neutrophils... 

---