Plays a role in cholinergic transmission and as a functional partner of dystrophin (dys-1), necessary for muscle maintenance. Component of the dystrophin glycoprotein complex (DGC). Interacts with dys-1 and syntrophin (stn-1) to form the DGC. From late embryogenesis to adulthood, expressed in neurons and muscles; particularly strong in the ventral nerve cord and in muscles of the body wall, head pharyngeal, and vulva; weaker in the intestinal muscle (at protein level). The coiled-coil domain mediates the specific interaction with dys-1. Mutants synergistically exhibit progressive myopathy. In dyb-1 and hlh-1 double mutants, there is an uncoordinated phenotype associated with some muscle degeneration. Overexpression of dyb-1 in dys-1 and hlh-1 double mutants delays, but does not prevent the onset and progression of myopathy. Belongs to the dystrophin family. Dystrobrevin subfamily.