disease:Defects in OPA1 are a cause of optic atrophy type 1 (OPA1) [MIM:165500]. OPA1 is a dominantly inherited optic neuropathy occurring in 1 in 50,000 individuals that features progressive loss in visual acuity leading, in many cases, to legal blindness.,disease:Defects in OPA1 are the cause of optic atrophy 1 and deafness [MIM:125250]. Some individuals with mutations in OPA1 manifest also ophthalmoplegia and myopathy.,function:Dynamin-related GTPase required for mitochondrial fusion and regulation of apoptosis. May form a diffusion barrier for proteins stored in mitochondrial cristae. Proteolytic processing in response to intrinsic apoptotic signals may lead to disassembly of OPA1 oligomers and release of the caspase activator cytochrome C (CYCS) into the mitochondrial intermembrane space.,PTM:PARL-dependent proteolytic processing releases an antiapoptotic soluble form not required for mitochondrial fusion.,similarity:Belongs to the dynamin family.,subunit:Oligomeric complex consisting of membrane-bound and soluble forms of OPA1. Binds PARL.,tissue specificity:Highly expressed in retina. Also expressed in brain, testis, heart and skeletal muscle. Isoform 1 expressed in retina, skeletal muscle, heart, lung, ovary, colon, thyroid gland, leukocytes and fetal brain. Isoform 2 expressed in colon, liver, kidney, thyroid gland and leukocytes. Low levels of all isoforms expressed in a variety of tissues.,
Mitochondrion inner membrane ; Single-pass membrane protein . Mitochondrion intermembrane space . Mitochondrion membrane . Detected at contact sites between endoplasmic reticulum and mitochondrion membranes. .
Highly expressed in retina. Also expressed in brain, testis, heart and skeletal muscle. Isoform 1 expressed in retina, skeletal muscle, heart, lung, ovary, colon, thyroid gland, leukocytes and fetal brain. Isoform 2 expressed in colon, liver, kidney, thyroid gland and leukocytes. Low levels of all isoforms expressed in a variety of tissues.