Prolactin stimulates ubiquitination, initial internalization, and degradation of its receptor via catalytic activation of Janus kinase 2
| Autor: | Christopher J. Carbone, Stuart J. Frank, Alexander Plotnikov, Charles V. Clevenger, K.G. Suresh Kumar, Vincent Goffin, Elizabeth M. Jablonski, Serge Y. Fuchs, Bentley Varghese, Luqin Deng, Chellappagounder Thangavel, Gayathri Swaminathan |
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| Rok vydání: | 2007 |
| Předmět: |
medicine.medical_specialty
Receptors Prolactin Endocrinology Diabetes and Metabolism media_common.quotation_subject Ligands Endocytosis Catalysis Cell Line Endocrinology Downregulation and upregulation Internal medicine medicine Humans Phosphorylation Receptor Internalization media_common Janus kinase 2 biology Chemistry Ubiquitination Janus Kinase 2 Prolactin Enzyme Activation biology.protein Signal transduction Janus kinase hormones hormone substitutes and hormone antagonists |
| Zdroj: | Journal of Endocrinology. 196:R1-R7 |
| ISSN: | 1479-6805 0022-0795 |
| DOI: | 10.1677/joe-07-0554 |
| Popis: | Prolactin (PRL) activates its receptor to initiate signal transduction pathways (including activation of Janus kinases, Jak) but also stimulates downregulation of this receptor to limit the magnitude and duration of signaling. Degradation of the long form of PRL receptor (PRLr) depends on its phosphorylation on Ser349 that is required to facilitate PRLr ubiquitination. Signaling events that mediate PRL-induced degradation of PRLr remain to be elucidated. Here, we investigated the role of Jak2 activity in ligand-triggered increase of PRLr phosphorylation on Ser349, PRLr ubiquitination, endocytosis, and degradation. Using Jak2 reconstitution in Jak2-null cells as well as pharmacologic approaches, we found that treatment with PRL (but not with PRLr antagonist) promotes phosphorylation of PRLr on Ser349 and accelerates endocytosis of PRLr. Furthermore, PRL-stimulated PRLr phosphorylation, endocytosis, and degradation in Jak2-null cells reconstituted with wild type but not with catalytically inactive Jak2. We discuss how Jak2-mediated signaling might be transduced into Ser349 phosphorylation of PRLr as well as its ubiquitination and endocytosis. |
| Databáze: | OpenAIRE |
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