Ankyrin repeat and sterile alpha motif domain-containing protein 4B (ANKS4B)

Ankyrin repeat and sterile alpha motif domain-containing protein 4B (ANKS4B) is a scaffolding protein found primarily in epithelial cells, where it localizes to the tips of brush border microvilli[2][3][5]. It is a core component of the intermicrovillar adhesion complex (IMAC), which is essential for proper organization, adhesion, and clustering of microvilli, critical for brush border assembly and function in the intestine and kidney[2][3]. Structurally, ANKS4B contains an N-terminal ankyrin repeat (ANKR) domain, a central unstructured region, and a C-terminal sterile alpha motif (SAM) with a PDZ-binding motif, enabling high-affinity interactions with other IMAC proteins including MYO7B and USH1C[2]. ANKS4B is not a classical therapeutic target such as an enzyme or receptor; rather, it acts as a multivalent scaffold, coordinating assembly and localization of proteins at the apical membrane. Disruption of ANKS4B impairs microvilli formation and brush border assembly, leading to epithelial structural defects[2][3]. While ANKS4B is not directly implicated in major human diseases as a drug target, it is related through pathway and protein interactions (notably with USH1C, mutations in which cause Usher syndrome)[2][3].

Other names

HARPHarmonin-interacting ankyrin repeat-containing proteinFLJ38819ankyrin repeat and SAM domain-containing protein 4BHarp