5miv
From Proteopedia
G307E variant of murine Apoptosis Inducing Factor in complex with NAD+
Structural highlights
Function[AIFM1_MOUSE] Functions both as NADH oxidoreductase and as regulator of apoptosis. In response to apoptotic stimuli, it is released from the mitochondrion intermembrane space into the cytosol and to the nucleus, where it functions as a proapoptotic factor in a caspase-independent pathway. In contrast, functions as an antiapoptotic factor in normal mitochondria via its NADH 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 (By similarity). Publication Abstract from PubMedThe apoptosis-inducing factor (AIF) is a FAD-containing protein playing critical roles in caspase-independent apoptosis and mitochondrial respiratory chain biogenesis and maintenance. While its lethal role is well known, the details of its mitochondrial function remain elusive. So far, nineteen allelic variants of AIF have been associated to human diseases, mainly affecting the nervous system. A strict correlation is emerging between the degree of impairment of its ability to stabilize the charge-transfer (CT) complex between FAD and NAD+ and the severity of the resulting pathology. Recently, we demonstrated that the G307E replacement in murine AIF (equivalent to the pathogenic G308E in the human protein) dramatically decreases the rate of CT complex formation through the destabilization of the flavoprotein interaction with NAD(H). To provide further insights into the structural bases of its altered functional properties, here we report the first crystal structure of an AIF pathogenic mutant variant in complex with NAD+ (murine AIF-G307ECT) in comparison with its oxidized form. With respect to wild type AIF, the mutation leads to an altered positioning of NAD+ adenylate moiety, which slows down CT complex formation. Moreover, the altered balance between the binding of the adenine/nicotinamide portions of the coenzyme determines a large drop in AIF-G307E ability to discriminate between NADH and NADPH. Structural bases of the altered catalytic properties of a pathogenic variant of apoptosis inducing factor.,Sorrentino L, Cossu F, Milani M, Aliverti A, Mastrangelo E Biochem Biophys Res Commun. 2017 Aug 26;490(3):1011-1017. doi:, 10.1016/j.bbrc.2017.06.156. Epub 2017 Jun 27. PMID:28666871[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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