Dataset Information

Inhibition of ESCRT-II-CHMP6 interactions impedes cytokinetic abscission and leads to cell death.

ABSTRACT: Recently the ESCRT-III filamentous complex was designated as the driving force for mammalian cell abscission, that is, fission of the intercellular membrane bridge connecting daughter cells at the end of cytokinesis. However, how ESCRT-III is activated to set on abscission has not been resolved. Here we revisit the role of the upstream canonical ESCRT players ESCRT-II and CHMP6 in abscission. Using high-resolution imaging, we show that these proteins form highly ordered structures at the intercellular bridge during abscission progression. Furthermore, we demonstrate that a truncated version of CHMP6, composed of its first 52 amino acids (CHMP6-N), arrives at the intercellular bridge, blocks abscission, and subsequently leads to cell death. This phenotype is abolished in a mutated version of CHMP6-N designed to prevent CHMP6-N binding to its ESCRT-II partner. Of interest, deleting the first 10 amino acids from CHMP6-N does not interfere with its arrival at the intercellular bridge but almost completely abolishes the abscission failure phenotype. Taken together, these data suggest an active role for ESCRT-II and CHMP6 in ESCRT-mediated abscission. Our work advances the mechanistic understanding of ESCRT-mediated membrane fission in cells and introduces an easily applicable tool for upstream inhibition of the ESCRT pathway in live mammalian cells.

SUBMITTER: Goliand I

PROVIDER: S-EPMC4230781 | biostudies-literature | 2014 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:In many eukaryotes, cytokinesis proceeds in two successive steps: first, ingression of the cleavage furrow and second, abscission of the intercellular bridge. In animal cells, the actomyosin contractile ring is involved in the first step, while the endosomal sorting complex required for transport (ESCRT), which participates in various membrane fusion/fission events, mediates the second step. Intriguingly, in archaea, ESCRT is involved in cytokinesis, raising the hypothesis that the function of ESCRT in eukaryotic cytokinesis descended from the archaeal ancestor. In eukaryotes other than in animals, the roles of ESCRT in cytokinesis are poorly understood. To explore the primordial core mechanisms for eukaryotic cytokinesis, we investigated ESCRT functions in the unicellular red alga Cyanidioschyzon merolae that diverged early in eukaryotic evolution. C. merolae provides an excellent experimental system. The cell has a simple organelle composition. The genome (16.5 Mb, 5335 genes) has been completely sequenced, transformation methods are established, and the cell cycle is synchronized by a light and dark cycle. Similar to animal and fungal cells, C. merolae cells divide by furrowing at the division site followed by abscission of the intercellular bridge. However, they lack an actomyosin contractile ring. The proteins that comprise ESCRT-I-IV, the four subcomplexes of ESCRT, are partially conserved in C. merolae. Immunofluorescence of native or tagged proteins localized the homologs of the five ESCRT-III components [charged multivesicular body protein (CHMP) 1, 2, and 4-6], apoptosis-linked gene-2-interacting protein X (ALIX), the ESCRT-III adapter, and the main ESCRT-IV player vacuolar protein sorting (VPS) 4, to the intercellular bridge. In addition, ALIX was enriched around the cleavage furrow early in cytokinesis. When the ESCRT function was perturbed by expressing dominant-negative VPS4, cells with an elongated intercellular bridge accumulated-a phenotype resulting from abscission failure. Our results show that ESCRT mediates cytokinetic abscission in C. merolae. The fact that ESCRT plays a role in cytokinesis in archaea, animals, and early diverged alga C. merolae supports the hypothesis that the function of ESCRT in cytokinesis descended from archaea to a common ancestor of eukaryotes.

Dataset Information

Inhibition of ESCRT-II-CHMP6 interactions impedes cytokinetic abscission and leads to cell death.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets