title: PTP-PEST controls EphA3 activation and ephrin-induced cytoskeletal remodelling.
abstract: Eph receptors and their corresponding membrane-bound ephrin ligands regulate cell positioning and establish tissue patterns during embryonic and oncogenic development. Emerging evidence suggests that assembly of polymeric Eph signalling clusters relies on cytoskeletal reorganisation and underlies regulation by protein tyrosine phosphatases (PTPs). PTP-PEST (also known as PTPN12) is a central regulator of actin cytoskeletal dynamics. Here, we demonstrate that an N-terminal fragment of PTP-PEST, generated through an ephrinA5-triggered and spatially confined cleavage mediated by caspase-3, attenuates EphA3 receptor activation and its internalisation. Isolation of EphA3 receptor signalling clusters within intact plasma membrane fragments obtained by detergent-free cell fractionation reveals that stimulation of cells with ephrin triggers effective recruitment of this catalytically active truncated form of PTP-PEST together with key cytoskeletal and focal adhesion proteins. Importantly, modulation of actin polymerisation using pharmacological and dominant-negative approaches affects EphA3 phosphorylation in a similar manner to overexpression of PTP-PEST. We conclude that PTP-PEST regulates EphA3 activation both by affecting cytoskeletal remodelling and through its direct action as a PTP controlling EphA3 phosphorylation, indicating its multifaceted regulation of Eph signalling.
authors.affiliation: Cancer Program, Monash Biomedicine Discovery Institute, and Department of Biochemistry and Molecular Biology, Monash University, Clayton, 3800 Victoria, Australia.
authors.forename: Mariam
authors.initials: M
authors.lastname: Mansour
authors.affiliation: Cancer Program, Monash Biomedicine Discovery Institute, and Department of Biochemistry and Molecular Biology, Monash University, Clayton, 3800 Victoria, Australia.
authors.forename: Eva
authors.initials: E
authors.lastname: Nievergall
authors.affiliation: Cancer Program, Monash Biomedicine Discovery Institute, and Department of Biochemistry and Molecular Biology, Monash University, Clayton, 3800 Victoria, Australia.
authors.forename: Kristina
authors.initials: K
authors.lastname: Gegenbauer
authors.affiliation: Cancer Program, Monash Biomedicine Discovery Institute, and Department of Biochemistry and Molecular Biology, Monash University, Clayton, 3800 Victoria, Australia.
authors.forename: Carmen
authors.initials: C
authors.lastname: Llerena
authors.affiliation: Cancer Program, Monash Biomedicine Discovery Institute, and Department of Biochemistry and Molecular Biology, Monash University, Clayton, 3800 Victoria, Australia.
authors.forename: Lakmali
authors.initials: L
authors.lastname: Atapattu
authors.affiliation: Goodman Cancer Research Centre & Department of Biochemistry, McGill University, Montreal H3A1A3, Quebec, Canada.
authors.forename: Maxime
authors.initials: M
authors.lastname: Hallé
authors.affiliation: Goodman Cancer Research Centre & Department of Biochemistry, McGill University, Montreal H3A1A3, Quebec, Canada.
authors.forename: Michel L
authors.initials: ML
authors.lastname: Tremblay
authors.affiliation: Cancer Program, Monash Biomedicine Discovery Institute, and Department of Biochemistry and Molecular Biology, Monash University, Clayton, 3800 Victoria, Australia peter.janes@monash.edu.
authors.forename: Peter W
authors.initials: PW
authors.lastname: Janes
authors.affiliation: Cancer Program, Monash Biomedicine Discovery Institute, and Department of Biochemistry and Molecular Biology, Monash University, Clayton, 3800 Victoria, Australia.
authors.forename: Martin
authors.initials: M
authors.lastname: Lackmann
mesh_terms: D000818:Animals; D019556:COS Cells; D053148:Caspase 3 / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002522:Chlorocebus aethiops; D003599:Cytoskeleton / Q000378:metabolism; D036386:Ephrin-A5 / Q000502:physiology*; D057809:HEK293 Cells; D006801:Humans; D010766:Phosphorylation; D011485:Protein Binding; D011499:Protein Processing, Post-Translational; D021381:Protein Transport; D054594:Protein Tyrosine Phosphatase, Non-Receptor Type 12 / Q000502:physiology*; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism*; D036121:Receptor, EphA3
chemical_list: D036386:Ephrin-A5; C491718:EPHA3 protein, human; D020794:Receptor Protein-Tyrosine Kinases; D036121:Receptor, EphA3; C516738:PTPN12 protein, human; D054594:Protein Tyrosine Phosphatase, Non-Receptor Type 12; C505407:CASP3 protein, human; D053148:Caspase 3
keywords: Actin cytoskeleton; Caspase cleavage; Eph tyrosine kinase; EphA3; PTP-PEST