Septin 9 (IPR030645)

Short name: SEPT9

Overlapping homologous superfamilies

Family relationships

  • Septin (IPR016491)
    • Septin 9 (IPR030645)


Septin 9 (SEPT9) belongs to the septin family. It negatively regulates ubiquitin-dependent downregulation of epidermal growth factor receptor [PMID: 25472714]. It has been linked to cancers [PMID: 25429690, PMID: 24633736].

Septins were first discovered in budding yeast as a major component of bud neck filaments during cell septation [PMID: 4950437, PMID: 773946]. Later, its homologues were identified in nearly all eukaryotes, including humans. They are all GTP-binding proteins that are involved in diverse cellular functions, including cell cycle progression, vesicle trafficking, cytokinesis, cell migration, membrane dynamics, and chromosome segregation [PMID: 24469395, PMID: 22314400]. Similar to cytoskeleton components such as actins and tubulins, they can assemble into filaments and bundles. However, unlike actin filaments and microtubules, septin filaments are not polar, similarly to intermediate filaments [PMID: 22314400]. The number of septin genes per organism is variable: S. cerevisiae has seven and humans have 13 (SEPT1-12 and SEPT14; SEPT13 is a pseudogene now called SEPT7P2) [PMID: 22314400]. All septins can form heteromeric complexes, which associate to form higher-order structures, including filaments, rings and cage-like formations [PMID: 22314400, PMID: 21990096].

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0005525 GTP binding

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.