Septin9 is involved in septin filament formation and cellular stability
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Abstract
Septin9 (Sept9) is a member of the filament-forming septin family of structural proteins and is associated with a variety of cancers and with hereditary neuralgic amyotrophy. We have generated mice with constitutive and conditional Sept9 knockout alleles. Homozygous deletion of Sept9 results in embryonic lethality around day 10 of gestation whereas mice homozygous for the conditional allele develop normally. Here we report the consequences of homozygous loss of Sept9 in immortalized murine embryonic fibroblasts. Proliferation rate was not changed but cells without Sept9 had an altered morphology compared to normal cells, particularly under low serum stress. Abnormal, fragmented, and multiple nuclei were more frequent in cells without Sept9. Cell migration, as measured by gap-filling and filter-invasion assays, was impaired, but individual cells did not move less than wild-type cells. Sept9 knockout cells showed a reduced resistance to hypo-osmotic stress. Stress fiber and vinculin staining at focal adhesion points was less prominent. Long septin filaments stained for Sept7 disappeared. Instead, staining was found in short, often curved filaments and rings. Furthermore, Sept7 was no longer localized to the mitotic spindle. Together, these data reveal the importance of Sept9 for septin filament formation and general cell stability.
©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
