Prolactin and ErbB4/HER4 Signaling Interact via Janus Kinase 2 to Induce Mammary Epithelial Cell Gene Expression Differentiation
| Autor: | H. Shelton Earp, Melissa Sandahl, Leah C. Miraglia, Rebecca S. Muraoka-Cook, Debra Hunter |
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| Rok vydání: | 2008 |
| Předmět: |
Receptor
ErbB-4 animal structures Receptors Prolactin Article Receptor tyrosine kinase Cell Line Mice chemistry.chemical_compound Mammary Glands Animal Endocrinology Pregnancy STAT5 Transcription Factor Animals Phosphorylation Molecular Biology Janus kinase 2 biology Prolactin receptor food and beverages JAK-STAT signaling pathway Cell Differentiation Epithelial Cells Tyrosine phosphorylation General Medicine Janus Kinase 2 Prolactin Enzyme Activation ErbB Receptors Gene Expression Regulation chemistry ROR1 biology.protein Cancer research Intercellular Signaling Peptides and Proteins Tyrosine Female Janus kinase hormones hormone substitutes and hormone antagonists Platelet-derived growth factor receptor Heparin-binding EGF-like Growth Factor Signal Transduction |
| Zdroj: | Molecular Endocrinology. 22:2307-2321 |
| ISSN: | 1944-9917 0888-8809 |
| DOI: | 10.1210/me.2008-0055 |
| Popis: | Differentiation of mammary epithelium in vivo requires signaling through prolactin and ErbB4/HER4-dependent mechanisms. Although stimulation of either the prolactin receptor or ErbB4/HER4 results in activation of the transcription factor signal transducer and activator of transcription 5A (STAT5A) and induction of lactogenic differentiation, how these pathways intersect is unknown. We show herein that prolactin signaling in breast cells cooperates with and is substantially enhanced by the receptor tyrosine kinase ErbB4/HER4. Prolactin and the ErbB4/HER4 ligand heparin-binding epidermal growth factor each induced STAT5A tyrosine phosphorylation and nuclear translocation; each pathway required the intracellular tyrosine kinase Janus kinase 2 (JAK2). We found that full prolactin-mediated STAT5A activation and binding to the endogenous beta-casein promoter required ErbB4/HER4 but did not require ErbB1/epidermal growth factor receptor. For example, prolactin-induced STAT5A activity was markedly diminished in cells overexpressing kinase inactive HER4, in cells transfected with small interfering RNAs to specifically knock down endogenous ErbB4/HER4 expression and in cells treated with a small molecule inhibitor that targets ErbB4 kinase. Interestingly, prolactin caused ErbB4/HER4 tyrosine phosphorylation in a JAK2 kinase-dependent manner. Finally, prolactin receptor, ErbB4/HER4, and JAK2 were coimmunoprecipitated from prolactin-treated but not untreated cells. These results suggest that prolactin signaling engages the ErbB4 pathway via JAK2 and that ErbB4 provides an important component of STAT5A-dependent lactogenic differentiation; this pathway integration may help explain the similar deficit in mammary development observed in gene-targeted mice deficient in prolactin receptor, JAK2, ErbB4, or STAT5A. |
| Databáze: | OpenAIRE |
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