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Protein tyrosine phosphatase 1B is a key regulator of IFNAR1 endocytosis and a target for antiviral therapies.
- Source :
-
Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2012 Nov 20; Vol. 109 (47), pp. 19226-31. Date of Electronic Publication: 2012 Nov 05. - Publication Year :
- 2012
-
Abstract
- Type 1 interferons (IFN1) elicit antiviral defenses by activating the cognate receptor composed of IFN-α/β receptor chain 1 (IFNAR1) and IFNAR2. Down-regulation of this receptor occurs through IFN1-stimulated IFNAR1 ubiquitination, which exposes a Y466-based linear endocytic motif within IFNAR1 to recruitment of the adaptin protein-2 complex (AP2) and ensuing receptor endocytosis. Paradoxically, IFN1-induced Janus kinase-mediated phosphorylation of Y466 is expected to decrease its affinity for AP2 and to inhibit the endocytic rate. To explain how IFN1 promotes Y466 phosphorylation yet stimulates IFNAR1 internalization, we proposed that the activity of a protein tyrosine phosphatase (PTP) is required to enable both events by dephosphorylating Y466. An RNAi-based screen identified PTP1B as a specific regulator of IFNAR1 endocytosis stimulated by IFN1, but not by ligand-independent inducers of IFNAR1 ubiquitination. PTP1B is a promising target for treatment of obesity and diabetes; numerous research programs are aimed at identification and characterization of clinically relevant inhibitors of PTP1B. PTP1B is capable of binding and dephosphorylating IFNAR1. Genetic or pharmacologic modulation of PTP1B activity regulated IFN1 signaling in a manner dependent on the integrity of Y466 within IFNAR1 in human cells. These effects were less evident in mouse cells whose IFNAR1 lacks an analogous motif. PTP1B inhibitors robustly augmented the antiviral effects of IFN1 against vesicular stomatitis and hepatitis C viruses in human cells and proved beneficial in feline stomatitis patients. The clinical significance of these findings in the context of using PTP1B inhibitors to increase the therapeutic efficacy of IFN against viral infections is discussed.
- Subjects :
- Amino Acid Sequence
Animals
HEK293 Cells
Humans
Ligands
Mice
Molecular Sequence Data
Phosphorylation drug effects
Phosphotyrosine metabolism
Protein Stability drug effects
Receptor, Interferon alpha-beta chemistry
Signal Transduction drug effects
Antiviral Agents pharmacology
Endocytosis drug effects
Protein Tyrosine Phosphatase, Non-Receptor Type 1 metabolism
Receptor, Interferon alpha-beta metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1091-6490
- Volume :
- 109
- Issue :
- 47
- Database :
- MEDLINE
- Journal :
- Proceedings of the National Academy of Sciences of the United States of America
- Publication Type :
- Academic Journal
- Accession number :
- 23129613
- Full Text :
- https://doi.org/10.1073/pnas.1211491109