title: Multisite phosphorylation of the NDC80 complex gradually tunes its microtubule-binding affinity.
abstract: Microtubule (MT) attachment to kinetochores is vitally important for cell division, but how these interactions are controlled by phosphorylation is not well known. We used quantitative approaches in vitro combined with molecular dynamics simulations to examine phosphoregulation of the NDC80 complex, a core kinetochore component. We show that the outputs from multiple phosphorylation events on the unstructured tail of its Hec1 subunit are additively integrated to elicit gradual tuning of NDC80-MT binding both in vitro and in silico. Conformational plasticity of the Hec1 tail enables it to serve as a phosphorylation-controlled rheostat, providing a new paradigm for regulating the affinity of MT binders. We also show that cooperativity of NDC80 interactions is weak and is unaffected by NDC80 phosphorylation. This in vitro finding strongly supports our model that independent molecular binding events to MTs by individual NDC80 complexes, rather than their structured oligomers, regulate the dynamics and stability of kinetochore-MT attachments in dividing cells.
authors: Physiology Department, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104.
authors: Anatoly V
authors: AV
authors: Zaytsev
authors: Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523.
authors: Jeanne E
authors: JE
authors: Mick
authors: Center for Theoretical Problems of Physico-Chemical Pharmacology, Russian Academy of Sciences, Moscow 119991, Russia.
authors: Evgeny
authors: E
authors: Maslennikov
authors: Physiology Department, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104.
authors: Boris
authors: B
authors: Nikashin
authors: Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523 jdeluca@colostate.edu gekate@mail.med.upenn.edu.
authors: Jennifer G
authors: JG
authors: DeLuca
authors: Physiology Department, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104 jdeluca@colostate.edu gekate@mail.med.upenn.edu.
authors: Ekaterina L
authors: EL
authors: Grishchuk
mesh_terms: D048750:Cell Nucleus Division / Q000502:physiology*; D003598:Cytoskeletal Proteins; D006801:Humans; D018386:Kinetochores / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism*; D010766:Phosphorylation; D011485:Protein Binding
chemical_list: D003598:Cytoskeletal Proteins; C120529:NDC80 protein, human; D009687:Nuclear Proteins