Journal article
Ligand stimulation induces clathrin- and Rab5-dependent downregulation of the kinase-dead EphB6 receptor preceded by the disruption of EphB6-Hsp90 interaction
Cellular signalling, Vol.26(12), pp.2645-2657
12/2014
DOI: 10.1016/j.cellsig.2014.08.007
PMID: 25152371
Abstract
Ligand-induced internalisation and subsequent downregulation of receptor tyrosine kinases (RTKs) serve to determine biological outputs of their signalling. Intrinsically kinase-deficient RTKs control a variety of biological responses, however, the mechanism of their downregulation is not well understood and its analysis is focused exclusively on the ErbB3 receptor.
The Eph group of RTKs is represented by the EphA and EphB subclasses. Each bears one kinase-inactive member, EphA10 and EphB6, respectively, suggesting an important role for these molecules in the Eph signalling network. While EphB6 effects on cell behaviour have been assessed, the mechanism of its downregulation remains elusive.
Our work reveals that EphB6 and its kinase-active relative, and signalling partner, EphB4, are downregulated in a similar manner in response to their common ligand, ephrin-B2. Following stimulation, both receptors are internalised through clathrin-coated pits and are degraded in lysosomes. Their targeting for lysosomal degradation relies on the activity of an early endosome regulator, the Rab5 GTPase, as this process is inhibited in the presence of a Rab5 dominant-negative mutant. EphB6 also interacts with the Hsp90 chaperone and EphB6 downregulation is preceded by their rapid dissociation. Moreover, the inhibition of Hsp90 results in EphB6 degradation, mimicking its ligand-induced downregulation. These processes appear to rely on overlapping mechanisms, since Hsp90 inhibition does not significantly enhance ligand-induced EphB6 elimination.
Taken together, our observations define a novel mechanism for intrinsically kinase-deficient RTK downregulation and support an intriguing model, where Hsp90 dissociation acts as a trigger for ligand-induced receptor removal.
•The kinase-deficient EphB6 receptor is actively downregulated upon stimulation.•EphB6 and kinase-active EphB4 follow the same route in their downregulation.•EphB6 interacts with Hsp90 and EphB6 elimination is preceded by their dissociation.•Hsp90 inhibition triggers EphB6 degradation at a rate mimicking its downregulation.•EphB6-Hsp90 dissociation is likely to serve as a trigger for EphB6 downregulation.
Details
- Title: Subtitle
- Ligand stimulation induces clathrin- and Rab5-dependent downregulation of the kinase-dead EphB6 receptor preceded by the disruption of EphB6-Hsp90 interaction
- Creators
- Odette Allonby - Department of Pathology, College of Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E5, CanadaAmr M El Zawily - Department of Pathology, College of Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E5, CanadaTanya Freywald - Department of Pathology, College of Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E5, CanadaDarrell D Mousseau - Department of Psychiatry, College of Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E5, CanadaJennifer Chlan - Department of Psychiatry, College of Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E5, CanadaDeborah Anderson - Department of Biochemistry, College of Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E5, CanadaAlexandre Benmerah - INSERM U1163, Laboratory of Inherited Kidney Diseases, 75015 Paris, FranceVishaldeep Sidhu - Department of Biochemistry, Research and Innovation Centre, University of Regina, Regina, SK,S4S 0A2, CanadaMohan Babu - Department of Biochemistry, Research and Innovation Centre, University of Regina, Regina, SK,S4S 0A2, CanadaJohn DeCoteau - Department of Pathology, College of Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E5, CanadaAndrew Freywald - Department of Pathology, College of Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
- Resource Type
- Journal article
- Publication Details
- Cellular signalling, Vol.26(12), pp.2645-2657
- DOI
- 10.1016/j.cellsig.2014.08.007
- PMID
- 25152371
- NLM abbreviation
- Cell Signal
- ISSN
- 0898-6568
- eISSN
- 1873-3913
- Publisher
- Elsevier Inc
- Grant note
- DOI: 10.13039/501100000024, name: Canadian Institutes of Health Research, award: COP-107969, RSN-132192; DOI: 10.13039/501100000106, name: SHRF, award: 2891; DOI: 10.13039/100008920, name: University of Saskatchewan
- Language
- English
- Date published
- 12/2014
- Academic Unit
- Biology
- Record Identifier
- 9984217417102771
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