MZT Proteins Form Multi-Faceted Structural Modules in the γ-Tubulin Ring Complex

• DOI: 10.1016/j.celrep.2020.107791
• Publication Date: 2020-06-30T18:19:30Z
• Authors: Michal Wieczorek; Tzu-Lun Huang; Linas Urnavicius; Kuo-Chiang Hsia; Tarun M. Kapoor
• Keywords: Models, Molecular; 0303 health sciences; MZT2; QH301-705.5; microtubule nucleation; MZT1; Article; Protein Structure, Secondary; 03 medical and health sciences; Tubulin; Multiprotein Complexes; cryo-EM; GCP6; Humans; γ-tubulin ring complex; Biology (General); Protein Multimerization; Peptides; Microtubule-Associated Proteins; HeLa Cells; Protein Binding

Microtubule organization depends on the γ-tubulin ring complex (γ-TuRC), a ∼2.3-MDa nucleation factor comprising an asymmetric assembly of and GCP2-GCP6. However, it is currently unclear how γ-TuRC-associated microproteins MZT1 MZT2 contribute to structure regulation holocomplex. Here, we report cryo-EM structures in context native human γ-TuRC. forms two subcomplexes with N-terminal α-helical domains GCP3 or GCP6 (GCP-NHDs) within γ-TuRC "lumenal bridge." We determine X-ray recombinant MZT1/GCP6-NHD find similar that identify additional MZT/GCP-NHD-like subcomplexes, one which located outer face comprises GCP2-NHD centrosomin motif 1 (CM1)-containing peptide. Our data reveal establish multi-faceted, structurally mimetic "modules" can expand structural regulatory interfaces