该基因编码膜相关鸟苷酸激酶（maguk）蛋白家族的一个成员，并作为紧密连接衔接蛋白，也调节粘附连接。紧密连接调节内皮细胞和上皮细胞之间离子和大分子的运动。该支架蛋白的多结构域，包括突触后密度95/盘大/带状闭塞区（PDZ）结构域、Src同源结构域（SH3）结构域、鸟苷酸激酶（GuK）结构域和独特的（U）基序，都有助于协调跨膜蛋白、胞浆蛋白和F-肌动蛋白的结合它们是紧密连接功能所必需的。选择性剪接导致编码不同亚型的多个转录变体[由RefSeq提供，2017年8月]
This gene encodes a member of the membrane-associated guanylate kinase (MAGUK) family of proteins, and acts as a tight junction adaptor protein that also regulates adherens junctions. Tight junctions regulate the movement of ions and macromolecules between endothelial and epithelial cells. The multidomain structure of this scaffold protein, including a postsynaptic density 95/disc-large/zona occludens (PDZ) domain, a Src homology (SH3) domain, a guanylate kinase (GuK) domain and unique (U) motifs all help to co-ordinate binding of transmembrane proteins, cytosolic proteins, and F-actin, which are required for tight junction function. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Aug 2017]