IQ Motif And SEC7 Domain Containing Protein 3 (IQSEC3)

IQSEC3 colocalized with ARF1 in COS-7 cells. GST pull-down assay showed that IQSEC3 increased the amount of GTP-bound ARF1 but not ARF6, suggesting that IQSEC3 can activate ARF1.The deduced 1,182-amino acid protein has an N-terminal coiled-coil motif, an IQ motif, a pleckstrin homology (PH) domain, a Sec7 domain, and a putative C-terminal PDZ-binding sequence. Quantitative RT-PCR analysis showed that IQSEC3 is expressed specifically in human adult brain with high levels in cerebral cortex and olfactory bulb and not in glioblastoma tissues, glioma cell lines, or human neural stem/precursor cells (NSPCs). Northern blot analysis detected an approximately 7-kb transcript in human adult brain. IQSEC3 protein colocalized with NeuN, a mature neuronal marker, mainly in the cytoplasm.