| First Author | Helmer RA | Year | 2010 |
| Journal | Mol Cell Endocrinol | Volume | 325 |
| Issue | 1-2 | Pages | 143-9 |
| PubMed ID | 20562009 | Mgi Jnum | J:163178 |
| Mgi Id | MGI:4821207 | Doi | 10.1016/j.mce.2010.05.010 |
| Citation | Helmer RA, et al. (2010) Prolactin-induced Jak2 phosphorylation of RUSH: a key element in Jak/RUSH signaling. Mol Cell Endocrinol 325(1-2):143-9 |
| abstractText | Jak2/Stat-mediated prolactin signaling culminates in Stat5a-DNA-binding. However, not all Jak2-dependent genes have Stat5 sites. Western analysis with inhibitors showed Jak2 is a proximal intermediate in prolactin-induced RUSH phosphorylation. Transfection assays with HRE-H9 cells showed the RUSH-binding site mediated the ability of prolactin to augment progesterone-dependent transcription of the RUSH gene. Jak2 inhibitors or targeted RUSH-site mutation blocked the prolactin effect. RUSH co-immunoprecipitated with phospho-Jak2 from nuclear extracts. Jak2 inhibitors abolished the nuclear pool of phospho-RUSH not the nuclear content of RUSH in HRE-H9 cells. Nucleolar-affiliated partners, e.g. nucleolin, were identified by microLC/MS/MS analysis of nuclear proteins that co-immunoprecipitated with RUSH/GST-RING. RUSH did not exclusively co-localize with fibrillarin to the nucleolus. MG-132 (proteasomal inhibitor) failed to block Tyrene CR4-mediated decrease in phospho-RUSH, and did not promote RUSH accumulation in the nucleolus. These studies authenticate prolactin-dependent Jak2 phosphorylation of RUSH, and provide functional implications on the RUSH network of nuclear interactions. |
