Search results for FXN

Showing 12 results out of 12

×

Species

Types

Compartments

Reaction types

Search properties

Species

Types

Compartments

Reaction types

Search properties

Protein (6 results from a total of 6)

Identifier: R-HSA-1362390
Species: Homo sapiens
Compartment: mitochondrial matrix
Primary external reference: UniProt: FXN: Q16595
Identifier: R-HSA-1299454
Species: Homo sapiens
Compartment: mitochondrial inner membrane
Primary external reference: UniProt: FXN: Q16595
Identifier: R-HSA-1299444
Species: Homo sapiens
Compartment: mitochondrial inner membrane
Primary external reference: UniProt: Q16595
Identifier: R-HSA-1299451
Species: Homo sapiens
Compartment: mitochondrial intermembrane space
Primary external reference: UniProt: Q16595
Identifier: R-HSA-8986117
Species: Homo sapiens
Compartment: mitochondrial matrix
Primary external reference: UniProt: Q16595
Identifier: R-HSA-1299445
Species: Homo sapiens
Compartment: mitochondrial matrix
Primary external reference: UniProt: Q16595

Complex (2 results from a total of 2)

Identifier: R-HSA-1362404
Species: Homo sapiens
Compartment: mitochondrial matrix
Identifier: R-HSA-1362398
Species: Homo sapiens
Compartment: mitochondrial matrix

Reaction (4 results from a total of 4)

Identifier: R-HSA-1362408
Species: Homo sapiens
Compartment: mitochondrial matrix
Iron-sulfur clusters are assembled on the scaffold, ISCU. Based on homology with bacterial IscU:IscS complexes (reviewed in Johnson et al. 2005), one molecule of ISCU is bound to each subunit of a NFS1 dimer (Marinoni et al. 2012). A single complex may thus be capable of assembling two 2Fe-2S clusters. Sulfide is provided by desulfuration of cysteine by NFS1:ISD11 (Biederbick et al. 2006, Shi et al. 2009, Tsai and Barondeau 2010). It has been proposed that ferrous iron is delivered by FXN (Gerber et al. 2003, Yoon and Cowan 2003, Schmucker et al. 2011) bound to ISCU (inferred from yeast, Wang and Craig 2008), although more recent studies suggested that FXN functions as an allosteric effector to stimulate sulfide transfer (Tsai et al. 2010). Holo-ISCU (ISCU bound to a newly synthesized 2Fe-2S cluster) transiently interacts with a dedicated HSP70 chaperone system including Mortalin (GRP75) and HSP20 and GLRX5 (GRX5). Electrons supplied by FDX2 (FDX1L) are required (Tong et al. 2003, Cai et al. 2017) and may reduce the sulfur from S0 to S2- (sulfide). NFU1 binds an Fe-S cluster (Tong et al. 2003, inferred from bacteria Yuvaniyama et al. 2000) and, from biochemical studies of bacterial NFU1 homologues, is proposed to be an intermediate Fe-S cluster carrier (Bandyopadhy et al. 2008). Mutations in human NFU1 affect only a subset of Fe-S proteins (Navarro-Sastre et al. 2011).
Identifier: R-HSA-1362416
Species: Homo sapiens
Compartment: mitochondrial matrix
Frataxin (FXN) specifically binds 2 atoms of ferrous iron per monomer (reviewed in Stemmler et al. 2010). Iron bound to Frataxin may (Yoon and Cowan 2003, Gerber et al. 2003) or may not (Schmucker et al. 2011) enhance the interaction of Frataxin with NFS1, ICSU, and ISD11. Frataxin was shown to stimulate the cysteine desulfurase activity of NFS1 and was proposed to be a regulator of sulfur production (Tsai et al. 2010). The formation of sulfide by NFS1 is most efficiently observed when NFS1 is in complex with ISD11, ISCU, and FXN in the presence of cysteine and iron. This means that only the complete system of NFS1, ISD11, ISCU, FXN, cysteine, and iron is fully active as a desulfurase. FXN therefore seems to be a regulator of the cysteine desulfurase permitting sulfide production only when all components needed for Fe-S cluster synthesis are present and the ISCU-bound Fe-S cluster can be formed.
Identifier: R-HSA-1299475
Species: Homo sapiens
Compartment: mitochondrial inner membrane, mitochondrial matrix
As inferred from the yeast TIM23 complex, the human TIMM23 complex transports precursor proteins across the inner membrane and into the matrix. As in yeast, subunits TIMM50, TIMM17, and TIMM23 are probably necessary for initiating translocation while the PAM complex with mtHSP70 (HSPA9, yeast SSC1) provides the motive force that drives the transport. mtHSP70 binding to the precursor pulls the protein into the matrix in a reaction requiring ATP hydrolysis. The yeast reaction appears to use a Brownian ratchet mechanism (Yamano et al. 2008).
In yeast experimentally verified substrates of TIM23 PAM include Hsp60 (HSP60 in human) and Yfh1 (Frataxin, FXN in human). Many other matrix proteins are believed to be substrates of the TIMM23 complex
Identifier: R-HSA-1299480
Species: Homo sapiens
Compartment: mitochondrial inner membrane, mitochondrial intermembrane space
As inferred from the yeast TIM23 complex, the human TIMM23 complex resides in the inner membrane of the mitochondrion and transfers precursor proteins to the matrix. The TIMM23 complex appears to adopt different configurations (and perhaps different subunit compositions) depending on whether the substrate is destined for the inner membrane or the matrix. Here we refer to the TIMM23 PAM complex as the configuration that delivers inner membrane proteins. The PAM17 subcomplex is required for this activity. The N-terminal presequence of precursors first interacts with TIMM50 and TIMM23 (Zhang et al. 2013). The TIMM17 and TIMM23 subunits form a channel and are required to initiate translocation of precursors.
In yeast experimentally verified substrates of TIM23:PAM include Hsp60 (HSP60 in human) and Yfh1 (Frataxin, FXN in human). Many other matrix proteins are believed to be substrates of the TIMM23 complex.
Cite Us!