GTPase, IMAP Family, Member 1 (GIMAP1)

The deduced 306-amino acid protein has a calculated molecular mass of 34.3 kD. IMAP1 contains an N-terminal RK endoplasmic reticulum (ER) retention signal, 5 motifs conserved in GTP-binding proteins, and a putative C-terminal transmembrane region. IMAP1 shares 43 to 46% identity with IMAP2, IMAP3 (IAN4L1), and IMAP4. Multiple-tissue expression array analysis detected predominant expression of IMAP1 in spleen and lower expression in lymph nodes. Transient transfection of Chinese hamster ovary cells resulted in colocalization of IMAP1 with ER resident proteins.

IMAP1 gene contains 3 exons. Exon 1 is untranslated, and exon 3 contains more than 94% of the coding sequence. The 5-prime flanking region of IMAP1 has several silencing elements.