Controls adherens junction integrity (PubMed:11715019). Required for the correct rate and completion of elongation of the embryos (PubMed:11715019). Interacts with dlj-1 (via L27 domain); the interaction regulates ajm-1 apical junction location. grdn-1-dependent localization at sensory neuron dendritic tips (PubMed:27623382). The coiled-coil domain is sufficient to localize to apical junctions (PubMed:11715019). Expressed by epithelial cells (PubMed:11715019). Expressed in sensory neuron dendritic tips (PubMed:27623382). Expression occurs in the embryonic hypodermis, pharynx and intestine, as well as in postembryonic epithelia, including the vulva, uterus, spermathecae, pharynx, intestine, hindgut, hypodermis and male tail. The coiled-coil domain is sufficient to localize to apical junctions. Mutant embryos enclose normally and initiate elongation without obvious morphological abnormalities, yet at a slower rate than the wild type. Elongation is consistently arrested at the 2-3-fold stage, accompanied by the formation of a large vacuole in the posterior region.