Structural investigation of a C-terminal EphA2 receptor mutant: Does mutation affect the structure and interaction properties of the Sam domain?(198 visite) Mercurio FA, Costantini S, Di Natale C, Pirone L, Guariniello S, Scognamiglio PL, Marasco D, Pedone EM, Leone M
*** IBB - CNR *** Institute of Biostructures and Bioimaging, CNR, Naples, Italy., Unita di Farmacologia Sperimentale, IRCCS - Istituto Nazionale Tumori "Fondazione G. Pascale", Naples, Italy., University of Naples Federico II, Department of Pharmacy and CIRPEB, Naples, Italy., Dottorato in Biologia Computazionale, Dipartimento di Biochimica, Biofisica e Patologia generale, Seconda Universita degli Studi di Napoli, Naples, Italy., Institute of Biostructures and Bioimaging, CNR, Naples, Italy; University of Naples Federico II, Department of Pharmacy and CIRPEB, Naples, Italy., Institute of Biostructures and Bioimaging, CNR, Naples, Italy. Electronic address: email@example.com.,
Ephrin A2 receptor (EphA2) plays a key role in cancer, it is up-regulated in several types of tumors and the process of ligand-induced receptor endocytosis, followed by degradation, is considered as a potential path to diminish tumor malignancy. Protein modulators of this mechanism are recruited at the cytosolic Sterile alpha motif (Sam) domain of EphA2 (EphA2-Sam) through heterotypic Sam-Sam associations. These interactions engage the C-terminal helix of EphA2 and close loop regions (the so called End Helix side). In addition, several studies report on destabilizing mutations in EphA2 related to cataract formation and located in/or close to the Sam domain. Herein, we analyzed from a structural point of view, one of these mutants characterized by the insertion of a novel 39 residue long polypeptide at the C-terminus of EphA2-Sam. A 3D structural model was built by computational methods and revealed partial disorder in the acquired C-terminal tail and a few residues participating in an alpha-helix and two short beta-strands. We investigated by CD and NMR studies the conformational properties in solution of two peptides encompassing the whole C-terminal tail and its predicted helical region, respectively. NMR binding experiments demonstrated that these peptides do not interact relevantly with either EphA2-Sam or its interactor Ship2-Sam. Molecular dynamics (MD) simulations further indicated that the EphA2 mutant could be represented only through a conformational ensemble and that the C-terminal tail should not largely wrap the EphA2-Sam End-Helix interface and affect binding to other Sam domains.
187 Records (182 escludendo Abstract e Conferenze). Impact factor totale: 709.572 (687.489 escludendo Abstract e Conferenze). Impact factor a 5 anni totale: 749.772 (727.536 escludendo Abstract e Conferenze).