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Symbol SEPTIN9 contributors: mct/npt - updated : 22-01-2019
HGNC name septin 9
HGNC id 7323
TRANSCRIPTS type messenger
text alternative splicing of exons 1 and 2
identificationnb exonstypebpproduct
ProteinkDaAAspecific expressionYearPubmed
12 splicing 3837 73 586 high expression have been observed in both breast cancer cell lines, primary breast cancers as well as other solid tumor malignancies 2000 10673329
  • MSF-A, or variant 1
  • septin isoform implicated in the tumorigenic transformation of mammary epithelial cells
  • interaction with JNK, a mitogen-activated protein kinase important in cellular stress responses, cell proliferation, and cell survival
  • functional role in driving cellular proliferation of mammary epithelial cells, a hallmark feature of oncogenesis that is directly relevant to breast cancer
  • a threonine AA within the N-terminal region of the long form of SEPT9
  • 11 splicing 3998 - 579 - 2000 10673329
  • MSF-B, or variant 2
  • 645 bp exon encodes a majority of the N-terminal proline-rich region, that play a role in SEPT9 filament formation
  • 12 - 4012 - 422 - 2000 10673329
    11 - 3951 - 422 - 2000 10673329
    10 - 3651 - 474 - 2000 10673329
  • exon 1 beta and loss of exon 2
  • regulated by translational control
  • may have a role in neoplasia (over-expression induces altered cell polarity and increased motility and can alter microtubule dynamics)
  • - - - - - predominant in tumours 2012 22278362
  • exon 1 zeta
  • in tumours, elevated levels of SEPT9_v4* mRNA, a transcript that is translated with enhanced efficiency leading to increased SEPT9 isoform 4 protein
  • 11 - 4469 - 568 - 2000 10673329
  • variant 3
  • 645 bp exon encodes a majority of the N-terminal proline-rich region, that play a role in SEPT9 filament formation
  • 10 - 3246 - 335 - 2000 10673329
    11 - 3780 - 568 - -
    10 - 3062 - 362 - -
    Type ubiquitous
       expressed in (based on citations)
    SystemOrgan level 1Organ level 2Organ level 3Organ level 4LevelPubmedSpeciesStageRna symbol
    Digestivemouthtongue  predominantly
    Lymphoid/Immunelymph node   highly
     thymus   highly
    Nervousbrain   highly Homo sapiens
    Reproductivefemale systembreastmammary gland highly
     female systemovary   
    SystemCellPubmedSpeciesStageRna symbol
    cell lineage
    cell lines
    at STAGE
    physiological period embryo
    Text neural crest cells, cephalic mesenchyme and mesenchymal cells in developing limb
  • a threonine AA within the N-terminal region of the long form of SEPT9 , and a consensus motif within the SEPT9 N-terminal domain that supports its association with the adaptor protein SH3KBP1
  • a xylose isomerase 1 domain
  • a conserved GTPase domain
  • a proline-rich motif
  • a polybasic region
  • a coiled-coil domain
    interspecies ortholog to murine Sept9
    ortholog to rattus sept9
  • cytoskeleton-related septin family
  • filament-forming GTPases family
  • CATEGORY transcription factor , protooncogene
    SUBCELLULAR LOCALIZATION     plasma membrane
    intracellular,cytoplasm,cytoskeleton,intermed filament
  • associate with the microtubule (MT) and actin cytoskeleton
  • basic FUNCTION
  • cell cycle control, candidate for ovarian tumor suppression gene
  • involved in T-cell lymphomagenesis
  • function through interaction with other septins and small GTPase Rho-mediated signaling
  • dispensable for the early stages of cell division, but is critical for the final separation of daughter cells
  • mediates the localization of the vesicle-tethering exocyst complex to the midbody, providing mechanistic insight into the role of SEPT9 during abscission
  • importance of SEPT9 for septin filament formation and general cell stability
  • guanosine triphosphatase-binding protein required for cytokinesis
  • assemble into rod-shaped oligomeric complexes that join end-on-end to form filaments
  • SEPT9 holds a terminal position in the septin octamers, mediating abscission-specific polymerization during cytokinesis
  • SEPT9 expression level directs the hexamer-to-octamer ratio, and the isoform composition and expression level together determine higher-order arrangements of septins
  • both SEPT9 and PIN1 are critical for mediating the final separation of daughter cells
  • plays multiple roles in abscission, one of which is regulated by the action of CDK1 and PIN1
  • negatively regulates EGFR degradation by preventing the association of the ubiquitin ligase CBL with SH3KBP1, resulting in reduced EGFR ubiquitylation
  • modulates likely the interactions of KIF17 with membrane cargo
  • SEPTIN2, SEPTIN7, and SEPTIN9 are required for efficient bacterial invasion
  • SEPT9 promotes the formation and maintenance of long stable MTs through a mechanism that may involve recruitment of unpolymerized tubulin to the MT lattice
  • expressed and synthesized during differentiation of human osteoclasts
  • play a previously unappreciated role in osteoclastic bone resorption
  • CELLULAR PROCESS nucleotide, transcription
    a component
  • SEPT2 forms a 1:1:1 complex with SEPT7 and SEPT9 and the three members of this complex colocalize along the length of the axoneme
    small molecule
  • interaction with SEPT4 and SEPT11
  • binding SEPT14 (Peterson 2007)
  • is a putative binding partner of PLK1, which has been shown to act as a regulator of cytokinesis
  • interaction with PIN1 is controlled by CDK1 and is necessary for timely cytokinesis
  • PIN1 interacts with SEPT9 upon mitotic phosphorylation at Thr-24 by CDK1
  • SH3KBP1-SEPT9 is localized exclusively to the plasma membrane, where SEPT9 is recruited to EGF-engaged receptors in a SH3KBP1-dependent manner
  • interaction between KIF17, a kinesin 2 family motor, and septin 9 (SEPT9)
  • contributed to alleviate liver fibrosis might partially through promoting activated hepatic stellate cells (HSCs) apoptosis and this anti-fibrogenesis effect might be blocked by DNMT3A mediated methylation of SEPT9
  • cell & other
    Phosphorylated by CDK1 creates a binding site for PIN1 that is required for cytokinesis
    Other regulated by Rho/ Rhotekin signaling
    corresponding disease(s) HNA
    Other morbid association(s)
    TypeGene ModificationChromosome rearrangementProtein expressionProtein Function
    tumoral   translocation    
    in a therapy-related acute myeloid leukemia with a t(11;17)(q23;q25).
    tumoral     --over  
    in diverses tumors
    tumoral fusion      
    with MLL in acute myeloid leukemia
    tumoral   deletion    
    in sporadic epithelial ovarian tumors
    tumoral     --low  
    by hypermethylation in the progression of colon neoplastic disease
    Variant & Polymorphism
    Candidate gene
  • novel approach for the early detection of CRC, using SEPT9 promoter methylation, micronuclei frequency and genotypes, with the potential to improve Colorectal Cancer (CRC) risk assessment
  • Therapy target
    promising tool in breast cancer detection and further emphasize the importance of analyzing and targeting SEPT9 isoform-specific expression and function
    pharmacological agents that inhibit SEPT9 methylation and increase its expression could be considered as valuable treatments for liver fibrosis