A systematic screen for morphological abnormalities during fission yeast sexual reproduction identifies a mechanism of actin aster formation for cell fusion.

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State: Public
Version: Final published version
Serval ID
serval:BIB_1935E91B15B1
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
A systematic screen for morphological abnormalities during fission yeast sexual reproduction identifies a mechanism of actin aster formation for cell fusion.
Journal
PLoS Genetics
Author(s)
Dudin O., Merlini L., Bendezú F.O., Groux R., Vincenzetti V., Martin S.G.
ISSN
1553-7404 (Electronic)
ISSN-L
1553-7390
Publication state
Published
Issued date
2017
Peer-reviewed
Oui
Volume
13
Number
4
Pages
e1006721
Language
english
Abstract
In non-motile fungi, sexual reproduction relies on strong morphogenetic changes in response to pheromone signaling. We report here on a systematic screen for morphological abnormalities of the mating process in fission yeast Schizosaccharomyces pombe. We derived a homothallic (self-fertile) collection of viable deletions, which, upon visual screening, revealed a plethora of phenotypes affecting all stages of the mating process, including cell polarization, cell fusion and sporulation. Cell fusion relies on the formation of the fusion focus, an aster-like F-actin structure that is marked by strong local accumulation of the myosin V Myo52, which concentrates secretion at the fusion site. A secondary screen for fusion-defective mutants identified the myosin V Myo51-associated coiled-coil proteins Rng8 and Rng9 as critical for the coalescence of the fusion focus. Indeed, rng8Δ and rng9Δ mutant cells exhibit multiple stable dots at the cell-cell contact site, instead of the single focus observed in wildtype. Rng8 and Rng9 accumulate on the fusion focus, dependent on Myo51 and tropomyosin Cdc8. A tropomyosin mutant allele, which compromises Rng8/9 localization but not actin binding, similarly leads to multiple stable dots instead of a single focus. By contrast, myo51 deletion does not strongly affect fusion focus coalescence. We propose that focusing of the actin filaments in the fusion aster primarily relies on Rng8/9-dependent cross-linking of tropomyosin-actin filaments.

Pubmed
Web of science
Open Access
Yes
Create date
25/04/2017 19:37
Last modification date
20/08/2019 12:49
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