Septin 3 (SEPT3)

Neuronal-specific septin-3 belongs to the septin family of GTPases. Members of this family are required for cytokinesis. Expression is upregulated by retinoic acid in a human teratocarcinoma cell line. The specific function of this gene has not been determined. Alternative splicing of this gene results in multiple transcript variants.

SEP3 shares almost 100% sequence identity with mouse neuronal-specific septin-3 and rat brain-specific G-septin. Alternative splicing leads to 3 SEP3 isoforms, SEP3A, SEP3B, and SEP3C, which encode proteins of 345, 337, and 71 amino acids, respectively. SEP3A and SEP3B contain a set of consensus sequence motifs for GTP binding, 2 predicted phosphorylation sites for PKG, and a conserved binding motif for SH3 domain-containing proteins.