This article may be too technical for most readers to understand.(April 2015) |
NUBPL | |||||||||||||||||||||||||
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Identifiers | |||||||||||||||||||||||||
Aliases | NUBPL , C14orf127, IND1, huInd1, nucleotide binding protein like, MC1DN21 | ||||||||||||||||||||||||
External IDs | OMIM: 613621 MGI: 1924076 HomoloGene: 11854 GeneCards: NUBPL | ||||||||||||||||||||||||
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Orthologs | |||||||||||||||||||||||||
Species | Human | Mouse | |||||||||||||||||||||||
Entrez | |||||||||||||||||||||||||
Ensembl | |||||||||||||||||||||||||
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RefSeq (mRNA) | |||||||||||||||||||||||||
RefSeq (protein) | |||||||||||||||||||||||||
Location (UCSC) | Chr 14: 31.49 – 31.86 Mb | Chr 12: 52.1 – 52.31 Mb | |||||||||||||||||||||||
PubMed search | [3] | [4] | |||||||||||||||||||||||
Wikidata | |||||||||||||||||||||||||
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Iron-sulfur protein NUBPL (IND1) also known as nucleotide-binding protein-like (NUBPL), IND1 homolog, Nucleotide-binding protein-like or huInd1 is an iron-sulfur (Fe/S) protein that, in humans, is encoded by the NUBPL gene, located on chromosome 14q12. It has an early role in the assembly of the mitochondrial complex I assembly pathway. [5] [6]
NUBPL is located on the q arm of chromosome 14 in position 12 and has 18 exons. [5] The NUBPL gene produces a 5.9 kDa protein composed of 54 amino acids. [7] [8] The structure of the protein includes a presumed iron-sulfur binding (CxxC) signature, a nucleotide-binding domain which has been highly conserved, and a mitochondrial targeting sequence in the N-terminal. [9] NUBPL is required for the assembly of complex I, which is composed of 45 evolutionally conserved core subunits, including both mitochondrial DNA and nuclear encoded subunits. One of its arms is embedded in the inner membrane of the mitochondria, and the other is embedded in the organelle. The two arms are arranged in an L-shaped configuration. The total molecular weight of the complex is 1MDa. [10]
The NUBPL gene encodes a protein that is a member of the Mrp/NBP35 ATP-binding family. This protein is required for the assembly of the mitochondrial membrane respiratory chain NADH dehydrogenase (Complex I), the first oligomeric enzymatic complex of the mitochondrial respiratory chain located in the inner mitochondrial membrane. [6] [5] Its role in assembly is the delivery of one or more iron–sulfur (Fe-S) clusters to complex I subunits in anaerobic conditions in vitro. [6] [9] The dysfunction of NUBPL results in an irregular assembly of the peripheral arm of complex I, which may lead to a decrease in activity. Knockdown of the protein also causes abnormal mitochondrial ultrastructure characterized by respiratory supercomplex remodeling, christa membrane loss, and abnormally high lactate levels. [11] [9]
Sheftel, et al. (2009) used RNA interference (RNAi) to delete the NUBPL gene in yeast ( Y. lipolytica ). They observed decreased levels and activity of mitochondrial complex I, leading them to conclude that NUBPL is required for complex I assembly and activity. Their experiments showed functional conservation of NUBPL in yeast and humans, an indication that the protein serves an important function. Sheftel, et al. observed structural abnormalities in mitochondria that were NUBPL-depleted mitochondria. [9]
The absence of NUBPL disrupts the early stage of the mitochondrial complex I assembly pathway. NUBPL-depleted cells were observed to have an abnormal sub complex of proteins normally found in the membrane arm of complex I. A decrease in the presence of complex I subunit proteins, NDUFS1, NDUFV1, NDUFS3, and NDUFA13 indicated a failure of normal complex I assembly. [9] Mitochondrial complex I deficiency involving the dysfunction of the mitochondrial respiratory chain may cause a wide range of clinical manifestations from lethal neonatal disease to adult-onset neurodegenerative disorders. Phenotypes include macrocephaly with progressive leukodystrophy, non-specific encephalopathy, cardiomyopathy, myopathy, liver disease, Leigh syndrome, Leber hereditary optic neuropathy, and some forms of Parkinson disease. [6]
High-throughput DNA sequencing was used to identify variants in 103 candidate genes in 103 patients with mitochondrial complex 1 disorders. Heterozygous variants in the NUBPL were identified in one patient. cDNA complementation studies showed that the variants can cause complex 1 deficiency. The finding in this patient is consistent with autosomal recessive inheritance NUBPL-associated complex I deficiency, and supports the pathogenicity of the variants that were identified. [11] Complex compound heterozygous variants were identified in the NUBPL gene in this patient. [11] In exon 2, a paternally-inherited G>A point mutation (c.166 G>A) resulting in missense substitution of gly56-to-arg (G56R) was observed. Two variants were maternally-inherited: T>C point mutation (c.815-27 T>C) that caused a splicing error and a complex deletion of exons 1-4 and duplication involving exon 7. Two of 232 (1%) control chromosomes were found to have the c.166 G>A pathogenic variant. This individual identified was noted to have motor delays and developmental delay at 2 years of age. [11] He never achieved independent walking. He developed myopathy, nystagmus, ataxia, upper motor neuron signs, and absence seizures. Brain MRI showed leukodystrophy with involvement of the cerebellar cortex and deep white matter. At age 8, he had spasticity, ataxia, and speech problems.
Several patients from with early MRI abnormalities of the cerebellum, deep cerebral white matter and corpus callosum. In this small sample, it was noted that later imaging studies showed improvements to the corpus callosum and cerebral white matter abnormalities, while the cerebellar abnormalities worsen and brainstem abnormalities arise. Using whole exome sequencing, four of the patients had a mitochondrial complex І deficiency identified using other laboratory methods. All four of the patients had compound pathogenic variants in the NUBPL gene. [12]
NUBPL has protein-protein interactions with DNAJB11, MTUS2, RNF2, and UFD1L. [6]
Succinate dehydrogenase complex subunit C, also known as succinate dehydrogenase cytochrome b560 subunit, mitochondrial, is a protein that in humans is encoded by the SDHC gene. This gene encodes one of four nuclear-encoded subunits that comprise succinate dehydrogenase, also known as mitochondrial complex II, a key enzyme complex of the tricarboxylic acid cycle and aerobic respiratory chains of mitochondria. The encoded protein is one of two integral membrane proteins that anchor other subunits of the complex, which form the catalytic core, to the inner mitochondrial membrane. There are several related pseudogenes for this gene on different chromosomes. Mutations in this gene have been associated with pheochromocytomas and paragangliomas. Alternatively spliced transcript variants have been described.
Succinate dehydrogenase [ubiquinone] iron-sulfur subunit, mitochondrial (SDHB) also known as iron-sulfur subunit of complex II (Ip) is a protein that in humans is encoded by the SDHB gene.
Succinate dehydrogenase complex, subunit A, flavoprotein variant is a protein that in humans is encoded by the SDHA gene. This gene encodes a major catalytic subunit of succinate-ubiquinone oxidoreductase, a complex of the mitochondrial respiratory chain. The complex is composed of four nuclear-encoded subunits and is localized in the mitochondrial inner membrane. SDHA contains the FAD binding site where succinate is deprotonated and converted to fumarate. Mutations in this gene have been associated with a form of mitochondrial respiratory chain deficiency known as Leigh Syndrome. A pseudogene has been identified on chromosome 3q29. Alternatively spliced transcript variants encoding different isoforms have been found for this gene.
Cytochrome b is a protein that in humans is encoded by the MT-CYB gene. Its gene product is a subunit of the respiratory chain protein ubiquinol–cytochrome c reductase, which consists of the products of one mitochondrially encoded gene, MT-CYB, and ten nuclear genes—UQCRC1, UQCRC2, CYC1, UQCRFS1, UQCRB, "11kDa protein", UQCRH, Rieske protein presequence, "cyt c1 associated protein", and Rieske-associated protein.
Cytochrome c1, heme protein, mitochondrial (CYC1), also known as UQCR4, MC3DN6, Complex III subunit 4, Cytochrome b-c1 complex subunit 4, or Ubiquinol-cytochrome-c reductase complex cytochrome c1 subunit is a protein that in humans is encoded by the CYC1 gene. CYC1 is a respiratory subunit of Ubiquinol Cytochrome c Reductase, which is located in the inner mitochondrial membrane and is part of the electron transport chain. Mutations in this gene may cause mitochondrial complex III deficiency, nuclear, type 6.
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 an 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 3, mitochondrial is an enzyme that in humans is encoded by the NDUFS3 gene on chromosome 11. This gene encodes one of the iron-sulfur protein (IP) components of mitochondrial NADH:ubiquinone oxidoreductase. Mutations in this gene are associated with Leigh syndrome resulting from mitochondrial complex I deficiency.
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] iron-sulfur protein 2, mitochondrial (NDUFS2) also known as NADH-ubiquinone oxidoreductase 49 kDa subunit is an enzyme that in humans is encoded by the NDUFS2 gene. The protein encoded by this gene is a core subunit of the mitochondrial membrane respiratory chain NADH dehydrogenase. Mutations in this gene are associated with mitochondrial complex I deficiency.
NADH-ubiquinone oxidoreductase 75 kDa subunit, mitochondrial (NDUFS1) is an enzyme that in humans is encoded by the NDUFS1 gene. The encoded protein, NDUFS1, is the largest subunit of complex I, located on the inner mitochondrial membrane, and is important for mitochondrial oxidative phosphorylation. Mutations in this gene are associated with complex I deficiency.
NADH dehydrogenase [ubiquinone] flavoprotein 2, mitochondrial (NDUFV2) is an enzyme that in humans is encoded by the NDUFV2 gene. The encoded protein, NDUFV2, is a subunit of complex I of the mitochondrial respiratory chain, which is located on the inner mitochondrial membrane and involved in oxidative phosphorylation. Mutations in this gene are implicated in Parkinson's disease, bipolar disorder, schizophrenia, and have been found in one case of early onset hypertrophic cardiomyopathy and encephalopathy.
NADH dehydrogenase [ubiquinone] iron-sulfur protein 7, mitochondrial, also knowns as NADH-ubiquinone oxidoreductase 20 kDa subunit, Complex I-20kD (CI-20kD), or PSST subunit is an enzyme that in humans is encoded by the NDUFS7 gene. The NDUFS7 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.
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] iron-sulfur protein 6, mitochondrial is an enzyme that in humans is encoded by the NDUFS6 gene.
FAD-dependent oxidoreductase domain-containing protein 1 (FOXRED1), also known as H17, or FP634 is an enzyme that in humans is encoded by the FOXRED1 gene. FOXRED1 is an oxidoreductase and complex I-specific molecular chaperone involved in the assembly and stabilization 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 FOXRED1 have been associated with Leigh syndrome and infantile-onset mitochondrial encephalopathy.
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.
Cytochrome c oxidase assembly protein COX15 homolog (COX15), also known as heme A synthase, is a protein that in humans is encoded by the COX15 gene. This protein localizes to the inner mitochondrial membrane and involved in heme A biosynthesis. COX15 is also part of a three-component mono-oxygenase that catalyses the hydroxylation of the methyl group at position eight of the protoheme molecule. Mutations in this gene has been reported in patients with hypertrophic cardiomyopathy as well as Leigh syndrome, and characterized by delayed onset of symptoms, hypotonia, feeding difficulties, failure to thrive, motor regression, and brain stem signs.
NADH:ubiquinone oxidoreductase complex assembly factor 4, (NDUFAF4) also known as Hormone-regulated proliferation-associated protein of 20 kDa, (HRPAP20) or C6orf66 is a protein that in humans is encoded by the NDUFAF4 gene. NDUFAF4 is a mitochondrial assembly protein involved in the assembly 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 complex I deficiency and infantile mitochondrial encephalomyopathy. Elevations in HRPAP20 have also been implicated in breast cancer.
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