Evidence that a septin diffusion barrier is dispensable for cytokinesis in budding yeast
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Abstract
Septins are essential for cytokinesis in Saccharomyces cerevisiae, but their precise roles remain elusive. Currently, it is thought that before cytokinesis, the hourglass-shaped septin structure at the mother-bud neck acts as a scaffold for assembly of the actomyosin ring (AMR) and other cytokinesis factors. At the onset of cytokinesis, the septin hourglass splits to form a double ring that sandwiches the AMR and may function as diffusion barriers to restrict diffusible cytokinesis factors to the division site. Here, we show that in cells lacking the septin Cdc10 or the septin-associated protein Bud4, the septins form a ring-like structure at the mother-bud neck that fails to re-arrange into a double ring early in cytokinesis. Strikingly, AMR assembly and constriction, the localization of membrane-trafficking and extracellular-matrix-remodeling factors, cytokinesis, and cell-wall-septum formation all occur efficiently in cdc10Δ and bud4Δ mutants. Thus, diffusion barriers formed by the septin double ring do not appear to be critical for S. cerevisiae cytokinesis. However, an AMR mutation and a septin mutation have synergistic effects on cytokinesis and the localization of cytokinesis proteins, suggesting that tethering to the AMR and a septin diffusion barrier may function redundantly to localize proteins to the division site.
©2011 by Walter de Gruyter Berlin Boston
Articles in the same Issue
- Editorial
- Highlight on septins
- HIGHLIGHT: EMBO WORKSHOP ‘SEPTINS’
- New insights into the phylogenetic distribution and evolutionary origins of the septins
- Dynamics of septin ring and collar formation in Saccharomyces cerevisiae
- Genetic interactions with mutations affecting septin assembly reveal ESCRT functions in budding yeast cytokinesis
- MLL-SEPTIN gene fusions in hematological malignancies
- Septin roles in tumorigenesis
- Characterization of presynaptic septin complexes in mammalian hippocampal neurons
- Characterization of human septin interactions
- Septin genomics: a road less travelled
- Septin9 is involved in septin filament formation and cellular stability
- Lethal phenotype of mice carrying a Sept11 null mutation
- ARTS, the unusual septin: structural and functional aspects
- Structural and biochemical properties of Sept7, a unique septin required for filament formation
- Septins at the annulus of mammalian sperm
- The mother-bud neck as a signaling platform for the coordination between spindle position and cytokinesis in budding yeast
- Evidence that a septin diffusion barrier is dispensable for cytokinesis in budding yeast
- Septins as key regulators of actin based processes in bacterial infection
Articles in the same Issue
- Editorial
- Highlight on septins
- HIGHLIGHT: EMBO WORKSHOP ‘SEPTINS’
- New insights into the phylogenetic distribution and evolutionary origins of the septins
- Dynamics of septin ring and collar formation in Saccharomyces cerevisiae
- Genetic interactions with mutations affecting septin assembly reveal ESCRT functions in budding yeast cytokinesis
- MLL-SEPTIN gene fusions in hematological malignancies
- Septin roles in tumorigenesis
- Characterization of presynaptic septin complexes in mammalian hippocampal neurons
- Characterization of human septin interactions
- Septin genomics: a road less travelled
- Septin9 is involved in septin filament formation and cellular stability
- Lethal phenotype of mice carrying a Sept11 null mutation
- ARTS, the unusual septin: structural and functional aspects
- Structural and biochemical properties of Sept7, a unique septin required for filament formation
- Septins at the annulus of mammalian sperm
- The mother-bud neck as a signaling platform for the coordination between spindle position and cytokinesis in budding yeast
- Evidence that a septin diffusion barrier is dispensable for cytokinesis in budding yeast
- Septins as key regulators of actin based processes in bacterial infection
