Thermogenin is a mitochondrial carrier protein found in brown adipose tissue (BAT). It is used to generate heat by non-shivering thermogenesis, and makes a quantitatively important contribution to countering heat loss in babies which would otherwise occur due to their high surface area-volume ratio.
An uncoupling protein (UCP) is a mitochondrial inner membrane protein that is a regulated proton channel or transporter. An uncoupling protein is thus capable of dissipating the proton gradient generated by NADH-powered pumping of protons from the mitochondrial matrix to the mitochondrial intermembrane space. The energy lost in dissipating the proton gradient via UCPs is not used to do biochemical work. Instead, heat is generated. This is what links UCP to thermogenesis. However, not every type of UCPs are related to thermogenesis. Although UCP2 and UCP3 are closely related to UCP1, UCP2 and UCP3 do not affect thermoregulatory abilities of vertebrates. UCPs are positioned in the same membrane as the ATP synthase, which is also a proton channel. The two proteins thus work in parallel with one generating heat and the other generating ATP from ADP and inorganic phosphate, the last step in oxidative phosphorylation. Mitochondria respiration is coupled to ATP synthesis, but is regulated by UCPs. UCPs belong to the mitochondrial carrier (SLC25) family.
Mitochondrial uncoupling protein 2 is a protein that in humans is encoded by the UCP2 gene.
Mitochondrial uncoupling protein 3 is a protein that in humans is encoded by the UCP3 gene. The gene is located in chromosome (11q13.4) with an exon count of 7 and is expressed on the inner mitochondrial membrane. Uncoupling proteins transfer anions from the inner mitochondrial membrane to the outer mitochondrial membrane, thereby separating oxidative phosphorylation from synthesis of ATP, and dissipating energy stored in the mitochondrial membrane potential as heat. Uncoupling proteins also reduce generation of reactive oxygen species.
Sialin, also known as H(+)/nitrate cotransporter and H(+)/sialic acid cotransporter, is a protein which in humans is encoded by the SLC17A5 gene.
Phosphate carrier protein, mitochondrial is a protein that in humans is encoded by the SLC25A3 gene. The encoded protein is a transmembrane protein located in the mitochondrial inner membrane and catalyzes the transport of phosphate ions across it for the purpose of oxidative phosphorylation. There are two significant isoforms of this gene expressed in human cells, which differ slightly in structure and function. Mutations in this gene can cause mitochondrial phosphate carrier deficiency (MPCD), a fatal disorder of oxidative phosphorylation symptomized by lactic acidosis, neonatal hypotonia, hypertrophic cardiomyopathy, and death within the first year of life.
The human ATP5F1C gene encodes the gamma subunit of an enzyme called mitochondrial ATP synthase.
Peroxisomal membrane protein PMP34 is a protein that in humans is encoded by the SLC25A17 gene.
Large neutral amino acids transporter small subunit 2 is a protein that in humans is encoded by the SLC7A8 gene.
ATP synthase subunit s, mitochondrial is an enzyme that in humans is encoded by the ATP5S gene.
Mitochondrial 2-oxoglutarate/malate carrier protein is a protein that in humans is encoded by the SLC25A11 gene. Inactivating mutations in this gene predispose to metastasic paraganglioma.
Brain mitochondrial carrier protein 1 is a protein that in humans is encoded by the SLC25A14 gene.
The human gene ATP5PD encodes subunit d of the peripheral stalk part of the enzyme mitochondrial ATP synthase.
Mitochondrial thiamine pyrophosphate carrier is a protein that in humans is encoded by the SLC25A19 gene.
Calcium-binding mitochondrial carrier protein Aralar1 is a protein that in humans is encoded by the SLC25A12 gene. Aralar is an integral membrane protein located in the inner mitochondrial membrane. Its primary function as an antiporter is the transport of cytoplasmic glutamate with mitochondrial aspartate across the inner mitochondrial membrane, dependent on the binding of one calcium ion. Mutations in this gene cause early infantile epileptic encephalopathy 39 (EIEE39), symptomized by global hypomyelination of the central nervous system, refractory seizures, and neurodevelopmental impairment. This gene has connections to autism.
Solute carrier family 25 member 39 is a protein that in humans is encoded by the SLC25A39 gene. The protein has been shown to be necessary for the import of the major antioxidant glutathione into the mitochondria.
Sirtuin 4, also known as SIRT4, is a mitochondrial protein which in humans is encoded by the SIRT4 gene. SIRT4 is member of the mammalian sirtuin family of proteins, which are homologs to the yeast Sir2 protein. SIRT4 exhibits NAD+-dependent deacetylase activity.
ADP/ATP translocase 2 is a protein that in humans is encoded by the SLC25A5 gene on the X chromosome.
Solute carrier family 25 member 22 is a protein that in humans is encoded by the SLC25A22 gene. This gene encodes a mitochondrial glutamate carrier. Mutations in this gene are associated with early infantile epileptic encephalopathy. Expression of this gene is increased in colorectal tumor cells.
Daniel Ricquier, is a French biochemist known for his work in mitochondria and hereditary metabolic diseases. Ricquier has been a member of the French Academy of Sciences since 2002, and a professor of biochemistry and Molecular Biology at the Faculty of Medicine of the University of Paris Descartes since 2003.
