Titel
The dimeric Golgi protein Gorab binds to Sas6 as a monomer to mediate centriole duplication
Autor*in
Emma Stepinac
Department of Medical Biochemistry, Max Perutz Labs, Medical University of Vienna
Magdalena Richter
Department of Genetics, University of Cambridge
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Abstract
The duplication and ninefold symmetry of the Drosophila centriole requires that the cartwheel molecule, Sas6, physically associates with Gorab, a trans-Golgi component. How Gorab achieves these disparate associations is unclear. Here, we use hydrogen–deuterium exchange mass spectrometry to define Gorab’s interacting surfaces that mediate its subcellular localization. We identify a core stabilization sequence within Gorab’s C-terminal coiled-coil domain that enables homodimerization, binding to Rab6, and thereby trans-Golgi localization. By contrast, part of the Gorab monomer’s coiled-coil domain undergoes an antiparallel interaction with a segment of the parallel coiled-coil dimer of Sas6. This stable heterotrimeric complex can be visualized by electron microscopy. Mutation of a single leucine residue in Sas6’s Gorab-binding domain generates a Sas6 variant with a sixteenfold reduced binding affinity for Gorab that cannot support centriole duplication. Thus, Gorab dimers at the Golgi exist in equilibrium with Sas6-associated monomers at the centriole to balance Gorab’s dual role.
Stichwort
General Immunology and MicrobiologyGeneral Biochemistry, Genetics and Molecular BiologyGeneral MedicineGeneral Neuroscience
Objekt-Typ
Sprache
Englisch [eng]
Persistent identifier
Erschienen in
Titel
eLife
Band
10
ISSN
2050-084X
Erscheinungsdatum
2021
Publication
eLife Sciences Publications, Ltd
Erscheinungsdatum
2021
Zugänglichkeit
Rechte
Rechteangabe
© 2021, Fatalska et al
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