title: Mechanistic basis of Nek7 activation through Nek9 binding and induced dimerization.
abstract: Mitotic spindle assembly requires the regulated activities of protein kinases such as Nek7 and Nek9. Nek7 is autoinhibited by the protrusion of Tyr97 into the active site and activated by the Nek9 non-catalytic C-terminal domain (CTD). CTD binding apparently releases autoinhibition because mutation of Tyr97 to phenylalanine increases Nek7 activity independently of Nek9. Here we find that self-association of the Nek9-CTD is needed for Nek7 activation. We map the minimal Nek7 binding region of Nek9 to residues 810-828. A crystal structure of Nek7(Y97F) bound to Nek9(810-828) reveals a binding site on the C-lobe of the Nek7 kinase domain. Nek7(Y97F) crystallizes as a back-to-back dimer between kinase domain N-lobes, in which the specific contacts within the interface are coupled to the conformation of residue 97. Hence, we propose that the Nek9-CTD activates Nek7 through promoting back-to-back dimerization that releases the autoinhibitory tyrosine residue, a mechanism conserved in unrelated kinase families.
authors.affiliation: Department of Biochemistry, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK.|Cancer Research UK Leicester Centre, Leicester LE1 9HN, UK.
authors.forename: Tamanna
authors.initials: T
authors.lastname: Haq
authors.affiliation: Department of Biochemistry, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK.|Cancer Research UK Leicester Centre, Leicester LE1 9HN, UK.
authors.forename: Mark W
authors.initials: MW
authors.lastname: Richards
authors.affiliation: Department of Biochemistry, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK.|Cancer Research UK Leicester Centre, Leicester LE1 9HN, UK.
authors.forename: Selena G
authors.initials: SG
authors.lastname: Burgess
authors.affiliation: Departament de Bioquimica i Biologia Molecular, Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Gallego
authors.affiliation: Department of Biochemistry, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK.|Cancer Research UK Leicester Centre, Leicester LE1 9HN, UK.
authors.forename: Sharon
authors.initials: S
authors.lastname: Yeoh
authors.affiliation: Department of Biochemistry, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK.|Cancer Research UK Leicester Centre, Leicester LE1 9HN, UK.
authors.forename: Laura
authors.initials: L
authors.lastname: O'Regan
authors.affiliation: Departament de Bioquimica i Biologia Molecular, Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Reverter
authors.affiliation: Cell and Developmental Biology Program, Institute for Research in Biomedicine, 08028 Barcelona, Spain.
authors.forename: Joan
authors.initials: J
authors.lastname: Roig
authors.affiliation: Department of Biochemistry, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK.|Cancer Research UK Leicester Centre, Leicester LE1 9HN, UK.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Fry
authors.affiliation: Department of Biochemistry, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK.|Cancer Research UK Leicester Centre, Leicester LE1 9HN, UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Bayliss
mesh_terms: D020816:Amino Acid Motifs; D001665:Binding Sites; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D019281:Dimerization; D006367:HeLa Cells; D006801:Humans; D000072379:NIMA-Related Kinases; D010766:Phosphorylation; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: C512685:NEK7 protein, human; C462119:NEK9 protein, human; D000072379:NIMA-Related Kinases; D017346:Protein Serine-Threonine Kinases