NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 13 is an enzyme that in humans is encoded by the NDUFA13 gene. [5] [6] [7] [8] The NDUFA13 protein is a subunit of NADH dehydrogenase (ubiquinone), which is located in the mitochondrial inner membrane and is the largest of the five complexes of the electron transport chain. [9] [10]
The NDUFA13 gene is located on the p arm of chromosome 19 in position 13.2 and spans 11,995 base pairs. [8] The gene produces a 17 kDa protein composed of 144 amino acids. [11] [12] NDUFA13 is a subunit of the enzyme NADH dehydrogenase (ubiquinone), the largest of the respiratory complexes. The structure is L-shaped with a long, hydrophobic transmembrane domain and a hydrophilic domain for the peripheral arm that includes all the known redox centers and the NADH binding site. [9] It has been noted that the N-terminal hydrophobic domain has the potential to be folded into an alpha helix spanning the inner mitochondrial membrane with a C-terminal hydrophilic domain interacting with globular subunits of Complex I. The highly conserved two-domain structure suggests that this feature is critical for the protein function and that the hydrophobic domain acts as an anchor for the NADH dehydrogenase (ubiquinone) complex at the inner mitochondrial membrane. NDUFA13 is one of about 31 hydrophobic subunits that form the transmembrane region of Complex I, but it is an accessory subunit that is believed not to be involved in catalysis. [13] The predicted secondary structure is primarily alpha helix, but the carboxy-terminal half of the protein has high potential to adopt a coiled-coil form. The amino-terminal part contains a putative beta sheet rich in hydrophobic amino acids that may serve as mitochondrial import signal. [8] [10] [14]
The human NDUFA13 gene codes for a subunit of Complex I of the respiratory chain, which transfers electrons from NADH to ubiquinone. [8] NADH binds to Complex I and transfers two electrons to the isoalloxazine ring of the flavin mononucleotide (FMN) prosthetic arm to form FMNH2. The electrons are transferred through a series of iron-sulfur (Fe-S) clusters in the prosthetic arm and finally to coenzyme Q10 (CoQ), which is reduced to ubiquinol (CoQH2). The flow of electrons changes the redox state of the protein, resulting in a conformational change and pK shift of the ionizable side chain, which pumps four hydrogen ions out of the mitochondrial matrix. [9]
NDUFA13 has a homologous protein known as GRIM-19, a cell-death regulatory protein. It is involved in interferon/all-trans-retinoic acid (IFN/RA) induced cell death. This form of apoptotic activity is inhibited by interaction with viral IRF1. GRIM-19 prevents the transactivation of signal-transducer and activator of transcription 3 (STAT3) target genes but not other STAT family members. [13]
The homologous protein to NDUFA13, GRIM-19, may play a role in Crohn's disease (CD), an inflammatory bowel disease (IBD) characterized by chronic inflammation of the intestinal epithelium. Its expression is decreased in the inflamed mucosa of patients with these diseases. Nucleotide-binding oligomerization domain-containing protein 2 (NOD2), also known as caspase recruitment domain-containing protein 15 (CARD15) or inflammatory bowel disease protein 1 (IBD1), functions as a mammalian cytosolic pathogen recognition molecule and plays an anti-bacterial role by limiting survival of intracellular invasive bacteria. GRIM-19 acts as a downstream anti-bacterial effector in CARD15-mediated innate mucosal responses by regulating intestinal epithelial cell responses to microbes. Following NOD2-mediated recognition of bacterial muramyl dipeptide, GRIM-19 is required for NF-κB activation, a key component in regulating the immune response to infection. [13] [15]
Respiratory complex I, EC 7.1.1.2 is the first large protein complex of the respiratory chains of many organisms from bacteria to humans. It catalyzes the transfer of electrons from NADH to coenzyme Q10 (CoQ10) and translocates protons across the inner mitochondrial membrane in eukaryotes or the plasma membrane of bacteria.
NADH dehydrogenase [ubiquinone] iron-sulfur protein 4, mitochondrial (NDUFS4) also known as NADH-ubiquinone oxidoreductase 18 kDa subunit is an enzyme that in humans is encoded by the NDUFS4 gene. This gene encodes a nuclear-encoded accessory subunit of the mitochondrial membrane respiratory chain NADH dehydrogenase. Complex I removes electrons from NADH and passes them to the electron acceptor ubiquinone. Mutations in this gene can cause mitochondrial complex I deficiencies such as Leigh syndrome.
NADH dehydrogenase [ubiquinone] iron-sulfur protein 8, mitochondrial also known as NADH-ubiquinone oxidoreductase 23 kDa subunit, Complex I-23kD (CI-23kD), or TYKY subunit is an enzyme that in humans is encoded by the NDUFS8 gene. The NDUFS8 protein is a subunit of NADH dehydrogenase (ubiquinone) also known as Complex I, which is located in the mitochondrial inner membrane and is the largest of the five complexes of the electron transport chain. Mutations in this gene have been associated with Leigh syndrome.
NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 1 is a protein that in humans is encoded by the NDUFA1 gene. The NDUFA1 protein is a subunit of NADH dehydrogenase (ubiquinone), which is located in the mitochondrial inner membrane and is the largest of the five complexes of the electron transport chain. Mutations in the NDUFA1 gene are associated with mitochondrial Complex I deficiency.
NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 5 is an enzyme that in humans is encoded by the NDUFA5 gene. The NDUFA5 protein is a subunit of NADH dehydrogenase (ubiquinone), which is located in the mitochondrial inner membrane and is the largest of the five complexes of the electron transport chain.
NADH dehydrogenase [ubiquinone] 1 beta subcomplex subunit 6, also known as complex I-B17, is a protein that in humans is encoded by the NDUFB6 gene. NADH dehydrogenase (ubiquinone) 1 beta subcomplex subunit 6, is an accessory subunit of the NADH dehydrogenase (ubiquinone) complex, located in the mitochondrial inner membrane. It is also known as Complex I and is the largest of the five complexes of the electron transport chain.
NADH dehydrogenase [ubiquinone] 1 beta subcomplex subunit 8, mitochondrial is an enzyme that in humans is encoded by the NDUFB8 gene. NADH dehydrogenase (ubiquinone) 1 beta subcomplex subunit 8 is an accessory subunit of the NADH dehydrogenase (ubiquinone) complex, located in the mitochondrial inner membrane. It is also known as Complex I and is the largest of the five complexes of the electron transport chain.
NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 6 is an enzyme that in humans is encoded by the NDUFA6 gene. The NDUFA6 protein is a subunit of NADH dehydrogenase (ubiquinone), which is located in the mitochondrial inner membrane and is the largest of the five complexes of the electron transport chain.
NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 2 is a protein that in humans is encoded by the NDUFA2 gene. The NDUFA2 protein is a subunit of NADH dehydrogenase (ubiquinone), which is located in the mitochondrial inner membrane and is the largest of the five complexes of the electron transport chain. Mutations in the NDUFA2 gene are associated with Leigh's syndrome.
NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 9 is an enzyme that in humans is encoded by the NDUFA9 gene. The NDUFA9 protein is a subunit of NADH:ubiquinone oxidoreductase, which is located in the mitochondrial inner membrane and is the largest of the five complexes of the electron transport chain. Mutations in NADH dehydrogenase (ubiquinone), also known as Complex I, frequently lead to complex neurodegenerative diseases such as Leigh's syndrome. In the case of NDUFA9, a mutation to the MT-ND3 gene might interrupt their interaction and formation of subcomplexes, compromising Complex I function and leading to disease.
NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 8 is an enzyme that in humans is encoded by the NDUFA8 gene. The NDUFA8 protein is a subunit of NADH dehydrogenase (ubiquinone), which is located in the mitochondrial inner membrane and is the largest of the five complexes of the electron transport chain.
NADH dehydrogenase [ubiquinone] iron-sulfur protein 5 is an enzyme that in humans is encoded by the NDUFS5 gene.
NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 12 is an enzyme that in humans is encoded by the NDUFA12 gene. The NDUFA12 protein is a subunit of NADH dehydrogenase (ubiquinone), which is located in the mitochondrial inner membrane and is the largest of the five complexes of the electron transport chain. Mutations in subunits of NADH dehydrogenase (ubiquinone), also known as Complex I, frequently lead to complex neurodegenerative diseases such as Leigh's syndrome that result from mitochondrial complex I deficiency.
NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 10 is an enzyme that in humans is encoded by the NDUFA10 gene. The NDUFA10 protein is a subunit of NADH dehydrogenase (ubiquinone), which is located in the mitochondrial inner membrane and is the largest of the five complexes of the electron transport chain. Mutations in subunits of NADH dehydrogenase (ubiquinone), also known as Complex I, frequently lead to complex neurodegenerative diseases such as Leigh's syndrome. Furthermore, reduced NDUFA10 expression levels due to FOXM1-directed hypermethylation are associated with human squamous cell carcinoma and may be related to other forms of cancer.
NADH dehydrogenase [ubiquinone] 1 beta subcomplex subunit 1 is an enzyme that in humans is encoded by the NDUFB1 gene. NADH dehydrogenase (ubiquinone) 1 beta subcomplex, 1, 7kDa is an accessory subunit of the NADH dehydrogenase (ubiquinone) complex, located in the mitochondrial inner membrane. It is also known as Complex I and is the largest of the five complexes of the electron transport chain.
NADH dehydrogenase [ubiquinone] 1 beta subcomplex subunit 7, also known as complex I-B18, is an enzyme that in humans is encoded by the NDUFB7 gene. NADH dehydrogenase (ubiquinone) 1 beta subcomplex subunit 7 is an accessory subunit of the NADH dehydrogenase (ubiquinone) complex, located in the mitochondrial inner membrane. It is also known as Complex I and is the largest of the five complexes of the electron transport chain.
NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 3 is a protein that in humans is encoded by the NDUFA3 gene. The NDUFA3 protein is a subunit of NADH dehydrogenase (ubiquinone), which is located in the mitochondrial inner membrane and is the largest of the five complexes of the electron transport chain.
NDUFA4, mitochondrial complex associated is a protein that in humans is encoded by the NDUFA4 gene. The NDUFA4 protein was first described to be a subunit of NADH dehydrogenase (ubiquinone), which is located in the mitochondrial inner membrane and is the largest of the five complexes of the electron transport chain. However, recent research has described NDUFA4 as a subunit of cytochrome c oxidase. Mutations in the NDUFA4 gene are associated with Leigh's syndrome.
NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 7 is an enzyme that in humans is encoded by the NDUFA7 gene. The NDUFA7 protein is a subunit of NADH dehydrogenase (ubiquinone), which is located in the mitochondrial inner membrane and is the largest of the five complexes of the electron transport chain.
NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 11 is an enzyme that in humans is encoded by the NDUFA11 gene. The NDUFA11 protein is a subunit of NADH dehydrogenase (ubiquinone), which is located in the mitochondrial inner membrane and is the largest of the five complexes of the electron transport chain Mutations in subunits of NADH dehydrogenase (ubiquinone), also known as Complex I, frequently lead to complex neurodegenerative diseases such as Leigh's syndrome. Mutations in this gene are associated with severe mitochondrial complex I deficiency.
This article incorporates text from the United States National Library of Medicine, which is in the public domain.
