Required for the maintenance of appropriate synaptic retrograde communication and the stabilization of muscle cell architecture or physiology. May play a role in anchoring the cytoskeleton to the plasma membrane. Component of the dystrophin associated protein complex (DAPC). Interacts with Dg, via the Dg WW domain binding sites. During embryogenesis and in third instar larvae, expression is seen in pericardial cells of the dorsal vessel and in the ventral nerve cord. Expression is absent from both the embryonic and larval musculature. Flies that have reduced expression of all isoforms (due to transgenic RNA interference targeting the common C-terminal region) exhibit severe muscle degeneration in larvae and adult flies. Muscles were either ruptured, absent, or the fibers were detached from their attachment sites at tendon cells. These are necrotic, not apoptotic processes.