dynamin-like 120 kD protein, mitochondrial; optic atrophy protein 1; contains: dynamin-like 120 kD protein, form S1 (OPA1, KIAA0567)

Function

• dynamin-related GTPase required for mitochondrial fusion & 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 & release of the caspase activator cytochrome C into the mitochondrial intermembrane space
• dynamin-like 120 kD protein, form S1: inactive form
  • produced by cleavage at S1 position by OMA1 following stress conditions that induce loss of mitochondrial membrane potential, leading to negative regulation of mitochondrial fusion
  • PARL-dependent proteolytic processing releases an antiapoptotic soluble form not required for mitochondrial fusion cleaved by OMA1 at position S1 following stress conditions
• oligomeric complex consisting of membrane-bound & soluble forms of OPA1
• interacts with CHCHD3 & IMMT
  • these interactions occur preferentially with soluble OPA1 forms
• binds PARL (putative)

Structure

belongs to the dynamin family

Compartment

• mitochondrial inner membrane
• mitochondrion intermembrane space

Alternative splicing

named isoforms=2

Expression

• highly expressed in retina
• also expressed in brain, testis, heart & skeletal muscle
• isoform 1 expressed in retina, skeletal muscle, heart, lung, ovary, colon, thyroid gland, leukocytes & fetal brain
• isoform 2 expressed in colon, liver, kidney, thyroid gland & leukocytes
• low levels of all isoforms expressed in a variety of tissues

Pathology

• defects in OPA1 are a cause of optic atrophy type 1
• defects in OPA1 are the cause of dominant optic atrophy plus syndrome

Notes

proteolytic processing near Gln-220 produces form S2

More general terms

• mitochondrial protein
• phosphoprotein

Additional terms

• optic atrophy 1 (Kyer-type optic atrophy)

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=4976
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:4976
• OMIM: https://mirror.omim.org/entry/125250
• OMIM: https://mirror.omim.org/entry/165500
• OMIM: https://mirror.omim.org/entry/605290
• UniProt: http://www.uniprot.org/uniprot/O60313.html