Mitochondrial membrane transport proteins, also known as mitochondrial carrier proteins, are proteins which exist in the membranes of mitochondria. They serve to transport molecules and other factors, such as ions, into or out of the organelles. Mitochondria contain both an inner and outer membrane, separated by the inter-membrane space, or inner boundary membrane. The outer membrane is porous, whereas the inner membrane restricts the movement of all molecules. The two membranes also vary in membrane potential and pH. These factors play a role in the function of mitochondrial membrane transport proteins. There are 53 discovered human mitochondrial membrane transporters, with many others that are known to still need discovered.
Mitochondrial import inner membrane translocase subunit Tim8 A, also known as deafness-dystonia peptide or protein is an enzyme that in humans is encoded by the TIMM8A gene. This translocase has similarity to yeast mitochondrial proteins that are involved in the import of metabolite transporters from the cytoplasm into the mitochondrial inner membrane. The gene is mutated in deafness-dystonia syndrome and it is postulated that MTS/DFN-1 is a mitochondrial disease caused by a defective mitochondrial protein import system.
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.
Mitochondrial import inner membrane translocase subunit Tim13 is an enzyme that in humans is encoded by the TIMM13 gene.
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] 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.
Mitochondrial import inner membrane translocase subunit Tim10 is an enzyme that in humans is encoded by the TIMM10 gene.
TIMMDC1 is a protein that in humans is encoded by the TIMMDC1 gene. It is a chaperone protein involved in constructing the membrane arm of mitochondrial Complex I. A frameshift mutation in an intron of this gene has been shown to cause failure to thrive, retardation of psychomotor development, infantile-onset hypotonia, and severe neurologic dysfunction. High expression of this gene has been associated with migration of lung cancer cells while depletion of the protein has been shown to affect regulation of apoptosis, the cell cycle, and cell migration.
Mitochondrial import inner membrane translocase subunit TIM44 is an enzyme that in humans is encoded by the TIMM44 gene.
Mitochondrial import inner membrane translocase subunit Tim23 is an enzyme that in humans is encoded by the TIMM23 gene.
Mitochondrial import inner membrane translocase subunit Tim17-A is an enzyme that in humans is encoded by the TIMM17A gene.
Mitochondrial import inner membrane translocase subunit TIM14 is an enzyme that in humans is encoded by the DNAJC19 gene on chromosome 3. TIM14 belongs to the DnaJ family, which has been involved in Hsp40/Hsp70 chaperone systems. As a mitochondrial chaperone, TIM14 functions as part of the TIM23 complex import motor to facilitate the import of nuclear-encoded proteins into the mitochondria. TIM14 also complexes with prohibitin complexes to regulate mitochondrial morphogenesis, and has been implicated in dilated cardiomyopathy with ataxia.
Mitochondrial import inner membrane translocase subunit Tim9 is an enzyme that in humans is encoded by the TIMM9 gene.
Mitochondrial import inner membrane translocase subunit Tim22 is an enzyme that in humans is encoded by the TIMM22 gene.
Caseinolytic peptidase B protein homolog (CLPB), also known as Skd3, is a mitochondrial AAA ATPase chaperone that in humans is encoded by the gene CLPB, which encodes an adenosine triphosphate-(ATP) dependent chaperone. Skd3 is localized in mitochondria and widely expressed in human tissues. High expression in adult brain and low expression in granulocyte is found. It is a potent protein disaggregase that chaperones the mitochondrial intermembrane space. Mutations in the CLPB gene could cause autosomal recessive metabolic disorder with intellectual disability/developmental delay, congenital neutropenia, progressive brain atrophy, movement disorder, cataracts, and 3-methylglutaconic aciduria. Recently, heterozygous, dominant negative mutations in CLPB have been identified as a cause of severe congenital neutropenia (SCN).
The translocase of the inner membrane (TIM) is a complex of proteins found in the inner mitochondrial membrane of the mitochondria. Components of the TIM complex facilitate the translocation of proteins across the inner membrane and into the mitochondrial matrix. They also facilitate the insertion of proteins into the inner mitochondrial membrane, where they must reside in order to function, these mainly include members of the mitochondrial carrier family of proteins.
Serine active site-containing protein 1, or Protein SERAC1 is a protein in humans that is encoded by the SERAC1 gene. The protein encoded by this gene is a phosphatidylglycerol remodeling protein found at the interface of mitochondria and endoplasmic reticula, where it mediates phospholipid exchange. The encoded protein plays a major role in mitochondrial function and intracellular cholesterol trafficking. Defects in this gene are a cause of 3-methylglutaconic aciduria with deafness, encephalopathy, and Leigh-like syndrome (MEGDEL). Two transcript variants, one protein-coding and the other non-protein coding, have been found for this gene.
Mitochondrial import inner membrane translocase subunit TIM16 also known as presequence translocated-associated motor subunit PAM16, mitochondria-associated granulocyte macrophage CSF-signaling molecule, or presequence translocated-associated motor subunit PAM16 is a protein that in humans is encoded by the PAM16 gene.
Chromosome 19 open reading frame 70, also known as QIL1, MICOS complex subunit MIC13 (MIC13) or Protein P117 is a protein that in humans is encoded by the C19orf70 gene.
Transmembrane protein 70 is a protein that in humans is encoded by the TMEM70 gene. It is a transmembrane protein located in the mitochondrial inner membrane involved in the assembly of the F1 and Fo structural subunits of ATP synthase. Mutations in this gene have been associated with neonatal mitochondrial encephalo-cardiomyopathy due to ATP synthase deficiency, causing a wide variety of symptoms including 3-methylglutaconic aciduria, lactic acidosis, mitochondrial myopathy, and cardiomyopathy.
