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.
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.
Forkhead box protein C2 (FOXC2) also known as forkhead-related protein FKHL14 (FKHL14), transcription factor FKH-14, or mesenchyme fork head protein 1 (MFH1) is a protein that in humans is encoded by the FOXC2 gene. FOXC2 is a member of the fork head box (FOX) family of transcription factors.
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.
Voltage-dependent anion channels, or mitochondrial porins, are a class of porin ion channel located on the outer mitochondrial membrane. There is debate as to whether or not this channel is expressed in the cell surface membrane.
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.
Equilibrative nucleoside transporter 1 (ENT1) is a protein that in humans is encoded by the SLC29A1 gene. Multiple alternatively spliced variants, encoding the same protein, have been found for this gene. Expressed on red blood cell surfaces, these variants make up the Augustine blood group system.
G-protein coupled receptor 3 is a protein that in humans is encoded by the GPR3 gene. The protein encoded by this gene is a member of the G protein-coupled receptor family of transmembrane receptors and is involved in signal transduction.
Anion exchange protein 2 (AE2) is a membrane transport protein that in humans is encoded by the SLC4A2 gene. AE2 is functionally similar to the Band 3 Cl−/HCO3− exchange protein.
Mitochondrial import receptor subunit TOM34 is a protein that in humans is encoded by the TOMM34 gene.
Voltage-dependent anion-selective channel 1 (VDAC-1) is a beta barrel protein that in humans is encoded by the VDAC1 gene located on chromosome 5. It forms an ion channel in the outer mitochondrial membrane (OMM) and also the outer cell membrane. In the OMM, it allows ATP to diffuse out of the mitochondria into the cytoplasm. In the cell membrane, it is involved in volume regulation. Within all eukaryotic cells, mitochondria are responsible for synthesis of ATP among other metabolite needed for cell survival. VDAC1 therefore allows for communication between the mitochondrion and the cell mediating the balance between cell metabolism and cell death. Besides metabolic permeation, VDAC1 also acts as a scaffold for proteins such as hexokinase that can in turn regulate metabolism.
Aquaporin-7 (AQP-7) is a protein that in humans is encoded by the AQP7 gene.
The ATP5MC2 gene is one of three human paralogs that encode membrane subunit c of the mitochondrial ATP synthase.
Brain mitochondrial carrier protein 1 is a protein that in humans is encoded by the SLC25A14 gene.
Mitochondrial uncoupling protein 4 is a protein that in humans is encoded by the SLC25A27 gene.
Voltage-dependent anion-selective channel protein 2 is a protein that in humans is encoded by the VDAC2 gene on chromosome 10. This protein is a voltage-dependent anion channel and shares high structural homology with the other VDAC isoforms. VDACs are generally involved in the regulation of cell metabolism, mitochondrial apoptosis, and spermatogenesis. Additionally, VDAC2 participates in cardiac contractions and pulmonary circulation, which implicate it in cardiopulmonary diseases. VDAC2 also mediates immune response to infectious bursal disease (IBD).
Voltage-dependent anion-selective channel protein 3 (VDAC3) is a protein that in humans is encoded by the VDAC3 gene on chromosome 8. The protein encoded by this gene is a voltage-dependent anion channel and shares high structural homology with the other VDAC isoforms. Nonetheless, VDAC3 demonstrates limited pore-forming ability and, instead, interacts with other proteins to perform its biological functions, including sperm flagella assembly and centriole assembly. Mutations in VDAC3 have been linked to male infertility, as well as Parkinson’s disease.
ADP/ATP translocase 2 is a protein that in humans is encoded by the SLC25A5 gene on the X chromosome.
Peptidase M20 domain containing 1 is a circulating enzyme which in humans is encoded by the PM20D1 gene. PM20D1 regulates bioactive N-acyl amide lipids and has been implicated in obesity, type 2 diabetes, pain, and Alzheimer's disease.
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.
