Enables protein self-association. Acts upstream of or within nuclear membrane organization. Located in endoplasmic reticulum lumen and nuclear inner membrane. Is integral component of nuclear inner membrane. Is expressed in several structures, including aorta; cartilage; future spinal cord; genitourinary system; and oral epithelium. Human ortholog(s) of this gene implicated in arrhythmogenic right ventricular cardiomyopathy; arrhythmogenic right ventricular dysplasia 5; and autosomal dominant Emery-Dreifuss muscular dystrophy 7. Orthologous to human TMEM43 (transmembrane protein 43). [provided by Alliance of Genome Resources, Apr 2022]