In molecular biology, the IMD domain (IRSp53 and MIM (missing in metastases) homology Domain) is a BAR-like domain of approximately 250 amino acids found at the N-terminus in the insulin receptor tyrosine kinase substrate p53 (IRSp53/BAIAP2) and in the evolutionarily related IRSp53/MIM (MTSS1) family.
Filopodium-inducing IMD activity is regulated by Cdc42 and Rac1 (Rho-family GTPases) and is SH3-independent.
The vertebrate SH3-containing subfamily is further divided into three groups according to the presence or absence of the WWB and the half-CRIB motif.
Helix 4 packs tightly against the other three helices, and thus represents an integral part of the domain.
The fold of the IMD domain closely resembles that of the BAR (Bin-Amphiphysin-RVS) domain, a functional module serving both as a sensor and inducer of membrane curvature.