GTPase, IMAP Family, Member 4 (GIMAP4)

GIMAP4 encodes a protein belonging to the GTP-binding superfamily and to the immuno-associated nucleotide (IAN) subfamily of nucleotide-binding proteins. The encoded protein of this gene may be negatively regulated by T-cell acute lymphocytic leukemia 1 (TAL1). In humans, the IAN subfamily genes are located in a cluster at 7q36.1.

recombinant IAN1 expressed in E. coli showed efficient and saturable GDP binding in a filter binding assay. Binding was highly dependent on Mg(2+) concentration. IAN1 did not bind GMP, and it had higher affinity for GDP than for a nonhydrolyzable analog of GTP. Recombinant IAN1 also showed intrinsic GTPase activity. During T- and B-lymphocyte activation, IAN1 expression was regulated at the posttranscriptional level.