Regulator of cell matrix adhesion having two related functions, one upstream of Actn organizing the Z line and the other downstream of integrins regulating assembly of integrin adhesion sites. Also required for the formation of myotendinous junctions in muscles. Interacts with alpha-actinin (Actn). Regulates or strengthens the link of integrins to the actin cytoskeleton. Expression is first detected in the proctodeum and the midgut primordium. In stage 11 embryos, expression is predominant in the leading edge of epidermal cells adjacent to the amnioserosa. Stage 12 embryos exhibit expression in the midgut and the leading edge. Expressed in several rows of germ band cells next to the leading edge at stage 14. Strong expression is visible in the midgut and pharyngeal muscles of stage 17 embryos. Also expressed in somatic muscles and visceral mesoderm. Colocalizes with mys (beta PS integrin) in myotendinous junctions and with Actn in muscle Z lines. Expressed both maternally and zygotically. Fails to form the muscle Z line. At the myotendinous junction, muscles detach with the onset of contractility. Intron retention.