4fdc
From Proteopedia
Crystal structure of the E493V mutant of human apoptosis inducing factor (AIF)
Structural highlights
Disease[AIFM1_HUMAN] Defects in AIFM1 are the cause of combined oxidative phosphorylation deficiency type 6 (COXPD6) [MIM:300816]. It is a mitochondrial disease resulting in a neurodegenerative disorder characterized by psychomotor delay, hypotonia, areflexia, muscle weakness and wasting.[1] [2] Function[AIFM1_HUMAN] Probable oxidoreductase that has a dual role in controlling cellular life and death; during apoptosis, it is translocated from the mitochondria to the nucleus to function as a proapoptotic factor in a caspase-independent pathway, while in normal mitochondria, it functions as an antiapoptotic factor via its oxidoreductase activity. The soluble form (AIFsol) found in the nucleus induces 'parthanatos' i.e. caspase-independent fragmentation of chromosomal DNA. Interacts with EIF3G,and thereby inhibits the EIF3 machinery and protein synthesis, and activates casapse-7 to amplify apoptosis. Plays a critical role in caspase-independent, pyknotic cell death in hydrogen peroxide-exposed cells. Binds to DNA in a sequence-independent manner.[3] [4] [5] Publication Abstract from PubMedCowchock syndrome (CMTX4) is a slowly progressive X-linked recessive disorder with axonal neuropathy, deafness, and cognitive impairment. The disease locus was previously mapped to an 11 cM region at chromosome X: q24-q26. Exome sequencing of an affected individual from the originally described family identified a missense change c.1478A>T (p.Glu493Val) in AIFM1, the gene encoding apoptosis-inducing factor (AIF) mitochondrion-associated 1. The change is at a highly conserved residue and cosegregated with the phenotype in the family. AIF is an FAD-dependent NADH oxidase that is imported into mitochondria. With apoptotic insults, a N-terminal transmembrane linker is cleaved off, producing a soluble fragment that is released into the cytosol and then transported into the nucleus, where it triggers caspase-independent apoptosis. Another AIFM1 mutation that predicts p.Arg201del has recently been associated with severe mitochondrial encephalomyopathy in two infants by impairing oxidative phosphorylation. The c.1478A>T (p.Glu493Val) mutation found in the family reported here alters the redox properties of the AIF protein and results in increased cell death via apoptosis, without affecting the activity of the respiratory chain complexes. Our findings expand the spectrum of AIF-related disease and provide insight into the effects of AIFM1 mutations. Cowchock syndrome is associated with a mutation in apoptosis-inducing factor.,Rinaldi C, Grunseich C, Sevrioukova IF, Schindler A, Horkayne-Szakaly I, Lamperti C, Landoure G, Kennerson ML, Burnett BG, Bonnemann C, Biesecker LG, Ghezzi D, Zeviani M, Fischbeck KH Am J Hum Genet. 2012 Dec 7;91(6):1095-102. doi: 10.1016/j.ajhg.2012.10.008. PMID:23217327[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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