Enables protein domain specific binding activity. Involved in several processes, including autophagosome maturation; protein stabilization; and protein targeting to lysosome involved in chaperone-mediated autophagy. Acts upstream of or within muscle cell cellular homeostasis. Located in late endosome membrane; lysosomal membrane; and phagocytic vesicle membrane. Is integral component of autophagosome membrane. Is expressed in central nervous system; egg cylinder; lung; and retina. Used to study Danon disease. Human ortholog(s) of this gene implicated in Danon disease and hypertrophic cardiomyopathy. Orthologous to human LAMP2 (lysosomal associated membrane protein 2). [provided by Alliance of Genome Resources, Apr 2022]