PTP1D is a positive regulator of the prolactin signal leading to beta-casein promoter activation.

摘要: Abstract Stimulation of the prolactin receptor (PRLR), a member cytokine/growth hormone family, results in activation associated Jak2 tyrosine kinase and downstream signaling pathways. We report that PTP1D, cytoplasmic protein phosphatase containing two Src homology 2 (SH2) domains, physically associates with PRLR-Jak2 complex is tyrosine-phosphorylated upon stimulation prolactin. The formation trimeric PRLR-Jak2-PTP1D critical for transmission lactogenic signal, while PTP1D phosphorylation necessary, but not sufficient. dominant negative inhibitory effect phosphatase-deficient mutant on expression beta-casein promoter-controlled reporter gene evidence an essential role fully functional regulation milk transcription.