Centriolin anchoring of exocyst and SNARE complexes at the midbody is required for secretory-vesicle-mediated abscission.
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.
Gromley
Adam
A
Program in Molecular Medicine, University of Massachusetts Medical Center, Worcester, Massachusetts 01605, USA.
Yeaman
Charles
C
Rosa
Jack
J
Redick
Sambra
S
Chen
Chun-Ting
CT
Mirabelle
Stephanie
S
Guha
Minakshi
M
Sillibourne
James
J
Doxsey
Stephen J
SJ
D018797:Cell Cycle Proteins / Q000378:metabolism*; D002461:Cell Line, Transformed; D048749:Cytokinesis / Q000502:physiology*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D046911:Macromolecular Substances / Q000378:metabolism; D008561:Membrane Fusion / Q000502:physiology; D008958:Models, Molecular; D022142:Secretory Vesicles / Q000378:metabolism*; D033921:Vesicular Transport Proteins / Q000378:metabolism
C474898:CNTRL protein, human; D018797:Cell Cycle Proteins; D046911:Macromolecular Substances; C118519:SNAPIN protein, human; D033921:Vesicular Transport Proteins; D049452:Green Fluorescent Proteins