Centriolin anchoring of exocyst and SNARE complexes at the midbody is required for secretory-vesicle-mediated abscission
Program in Molecular Medicine
Medical Subject Headings
Cell Cycle Proteins; Cell Line, Transformed; Cytokinesis; Green Fluorescent Proteins; Humans; Macromolecular Substances; Membrane Fusion; Models, Molecular; Secretory Vesicles; Vesicular Transport Proteins
Cell and Developmental Biology | Life Sciences | Medicine and Health Sciences
The terminal step in cytokinesis, called abscission, requires resolution of the membrane connection between two prospective daughter cells. Our previous studies demonstrated that the coiled-coil protein centriolin localized to the midbody during cytokinesis and was required for abscission. Here we show that centriolin interacts with proteins of vesicle-targeting exocyst complexes and vesicle-fusion SNARE complexes. These complexes require centriolin for localization to a unique midbody-ring structure, and disruption of either complex inhibits abscission. Exocyst disruption induces accumulation of v-SNARE-containing vesicles at the midbody ring. In control cells, these v-SNARE vesicles colocalize with a GFP-tagged secreted polypeptide. The vesicles move to the midbody ring asymmetrically from one prospective daughter cell; the GFP signal is rapidly lost, suggesting membrane fusion; and subsequently the cell cleaves at the site of vesicle delivery/fusion. We propose that centriolin anchors protein complexes required for vesicle targeting and fusion and integrates membrane-vesicle fusion with abscission.
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Citation: Cell. 2005 Oct 7;123(1):75-87. Link to article on publisher's site