The region featured in this family is found towards the N-terminus of a number of adaptor proteins that interact with Abl-family tyrosine kinases [1]. More specifically, it is termed the homeo-domain homologous region (HHR), as it is similar to the DNA-binding region of homeo-domain proteins [2]. Other homeo-domain proteins have been implicated in specifying positional information during embryonic development, and in the regulation of the expression of cell-type specific genes [2]. The Abl-interactor proteins are thought to coordinate the cytoplasmic and nuclear functions of the Abl-family kinases, and seem to be involved in cytoskeletal reorganisation, but their precise role remains unclear [1].

1: In search of a function for the E3B1/Abi2/Argbp1/NESH family (Review). Ichigotani Y, Fujii K, Hamaguchi M, Matsuda S; Int J Mol Med 2002;9:591-595. PMID:12011975

2: Abi-2, a novel SH3-containing protein interacts with the c-Abl tyrosine kinase and modulates c-Abl transforming activity. Dai Z, Pendergast AM; Genes Dev 1995;9:2569-2582. PMID:7590236