title: MOZART1 and γ-tubulin complex receptors are both required to turn γ-TuSC into an active microtubule nucleation template.
abstract: MOZART1/Mzt1 is required for the localization of γ-tubulin complexes to microtubule (MT)-organizing centers from yeast to human cells. Nevertheless, the molecular function of MOZART1/Mzt1 is largely unknown. Taking advantage of the minimal MT nucleation system of Candida albicans, we reconstituted the interactions of Mzt1, γ-tubulin small complex (γ-TuSC), and γ-tubulin complex receptors (γ-TuCRs) Spc72 and Spc110 in vitro. With affinity measurements, domain deletion, and swapping, we show that Spc110 and Mzt1 bind to distinct regions of the γ-TuSC. In contrast, both Mzt1 and γ-TuSC interact with the conserved CM1 motif of Spc110/Spc72. Spc110/Spc72 and Mzt1 constitute "oligomerization chaperones," cooperatively promoting and directing γ-TuSC oligomerization into MT nucleation-competent rings. Consistent with the functions of Mzt1, human MOZART1 directly interacts with the CM1-containing region of the γ-TuCR CEP215. MOZART1 depletion in human cells destabilizes the large γ-tubulin ring complex and abolishes CEP215CM1-induced ectopic MT nucleation. Together, we reveal conserved functions of MOZART1/Mzt1 through interactions with γ-tubulin complex subunits and γ-TuCRs.
authors.affiliation: Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH-Allianz, 69120 Heidelberg, Germany.
authors.forename: Tien-Chen
authors.initials: TC
authors.lastname: Lin
authors.affiliation: Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH-Allianz, 69120 Heidelberg, Germany.
authors.forename: Annett
authors.initials: A
authors.lastname: Neuner
authors.affiliation: Biochemistry Center, 69120 Heidelberg, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Flemming
authors.affiliation: Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH-Allianz, 69120 Heidelberg, Germany.
authors.forename: Peng
authors.initials: P
authors.lastname: Liu
authors.affiliation: Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH-Allianz, 69120 Heidelberg, Germany.
authors.forename: Takumi
authors.initials: T
authors.lastname: Chinen
authors.affiliation: Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH-Allianz, 69120 Heidelberg, Germany.
authors.forename: Ursula
authors.initials: U
authors.lastname: Jäkle
authors.affiliation: Université Côte d'Azur, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Institut de Biologie Valrose, 06108 Nice, France.
authors.forename: Robert
authors.initials: R
authors.lastname: Arkowitz
authors.affiliation: Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH-Allianz, 69120 Heidelberg, Germany schiebel.elmar@zmbh.uni-heidelberg.de.
authors.forename: Elmar
authors.initials: E
authors.lastname: Schiebel
mesh_terms: D002176:Candida albicans / Q000378:metabolism*; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism*; D008954:Models, Biological; D011485:Protein Binding; D000072417:Protein Domains; D055503:Protein Multimerization; D055550:Protein Stability; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D008941:Spindle Apparatus / Q000378:metabolism; D064048:Spindle Pole Bodies / Q000378:metabolism; D014404:Tubulin / Q000378:metabolism*
chemical_list: D005656:Fungal Proteins; C000589193:MZT1 protein, human; D008869:Microtubule-Associated Proteins; D014404:Tubulin