Septin-9 (SEPTIN9)

Septin-9 is a member of the highly conserved septin family of GTPases that form hetero-oligomeric complexes and filaments within the cytoskeleton[1][2][3][4][5]. It is essential for organizing actin and microtubule networks, playing a key role in cytokinesis, cell polarity, vesicle traffic, and membrane dynamics[1][2][3][5]. Septin-9 also interacts with other proteins to scaffold cellular processes and create diffusion barriers for compartmentalization. The protein participates in tumor suppression, but its dysregulation is implicated in oncogenesis, cancer progression, and resistance to certain chemotherapies[3][4]. The SEPTIN9 gene generates multiple isoforms via alternative splicing, further increasing its functional complexity[4][5]. Septin-9’s activity and expression patterns make it both a biomarker and potential therapeutic target for cancer, particularly colorectal cancer where SEPTIN9 methylation is used for noninvasive screening[3][4]. Its role in cell polarity, cytoskeleton regulation, and membrane structure is vital for normal development and tissue maintenance, as well as disease processes[1][2][3][4].

Other names

KIAA0991MSFSEPT9MLL septin-like fusion proteinOv/Br septinMSF1PNUTL4AF17q25SeptD1MSF-AOvarian/Breast septinpeanut-like 4NAPBSINT1

Disruption or stabilization of septin filaments alters cell division and cytoskeletal dynamics Modulation of microtubule or actin-associated functions can affect sensitivity to chemotherapeutic agents