{PDOC00189} {PS50920; SOLCAR} {BEGIN} ****************************************** * Solute carrier (Solcar) repeat profile * ****************************************** Different types of substrate carrier proteins involved in energy transfer are found in the inner mitochondrial membrane [1 to 5]. These are: - The ADP,ATP carrier protein (AAC) (ADP/ATP translocase) which exports ATP into the cytosol and imports ADP into the mitochondrial matrix. The sequence of AAC has been obtained from various mammalian, plant and fungal species. - The 2-oxoglutarate/malate carrier protein (OGCP), which exports 2-oxoglutarate into the cytosol and imports malate or other dicarboxylic acids into the mitochondrial matrix. This protein plays an important role in several metabolic processes such as the malate/aspartate and the oxoglutarate/isocitrate shuttles. - The phosphate carrier protein, which transports phosphate groups from the cytosol into the mitochondrial matrix. - The brown fat uncoupling protein (UCP) which dissipates oxidative energy into heat by transporting protons from the cytosol into the mitochondrial matrix. - The tricarboxylate transport protein (or citrate transport protein) which is involved in citrate-H+/malate exchange. It is important for the bioenergetics of hepatic cells as it provides a carbon source for fatty acid and sterol biosyntheses, and NAD for the glycolytic pathway. - The Grave's disease carrier protein (GDC), a protein of unknown function recognized by IgG in patients with active Grave's disease. - Yeast mitochondrial proteins MRS3 and MRS4. The exact function of these proteins is not known. They suppress a mitochondrial splice defect in the first intron of the COB gene and may act as carriers, exerting their suppressor activity by modulating solute concentrations in the mitochondrion. - Yeast mitochondrial FAD carrier protein (gene FLX1). - Yeast protein ACR1 [6], which seems essential for acetyl-CoA synthase activity. - Yeast protein PET8. - Yeast protein PMT. - Yeast protein RIM2. - Yeast protein YHM1/SHM1. - Yeast protein YMC1. - Yeast protein YMC2. - Yeast hypothetical proteins YBR291c, YEL006w, YER053c, YFR045w, YHR002w, and YIL006w. - Caenorhabditis elegans hypothetical protein K11H3.3. Two other proteins have been found to belong to this family, yet are not localized in the mitochondrial inner membrane: - Maize amyloplast Brittle-1 protein. This protein, found in the endosperm of kernels, could play a role in amyloplast membrane transport. - Candida boidinii peroxisomal membrane protein PMP47 [7]. PMP47 is an integral membrane protein of the peroxisome and it may play a role as a transporter. These proteins all seem to be evolutionary related. Structurally, they consist of three tandem repeats of a domain of approximately one hundred residues. Each of these domains contains two transmembrane regions. The profile we developed covers the entire solute carrier (Solcar) repeat. -Sequences known to belong to this class detected by the profile: ALL. -Other sequence(s) detected in Swiss-Prot: NONE. -Last update: August 2003 / Pattern removed and profile added. [ 1] Klingenberg M. "Mechanism and evolution of the uncoupling protein of brown adipose tissue." Trends Biochem. Sci. 15:108-112(1990). PubMed=2158156 [ 2] Walker J.E. Curr. Opin. Struct. Biol. 2:519-526(1992). [ 3] Kuan J., Saier M.H. Jr. CRC Crit. Rev. Biochem. 28:209-233(1993). [ 4] Kuan J., Saier M.H. Jr. "Expansion of the mitochondrial carrier family." Res. Microbiol. 144:671-672(1993). PubMed=8140286 [ 5] Nelson D.R., Lawson J.E., Klingenberg M., Douglas M.G. "Site-directed mutagenesis of the yeast mitochondrial ADP/ATP translocator. Six arginines and one lysine are essential." J. Mol. Biol. 230:1159-1170(1993). PubMed=8487299 [ 6] Palmieri F. "Mitochondrial carrier proteins." FEBS Lett. 346:48-54(1994). PubMed=8206158 [ 7] Jank B., Habermann B., Schweyen R.J., Link T.A. "PMP47, a peroxisomal homologue of mitochondrial solute carrier proteins." Trends Biochem. Sci. 18:427-428(1993). PubMed=8291088 -------------------------------------------------------------------------------- PROSITE is copyrighted by the SIB Swiss Institute of Bioinformatics and distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives (CC BY-NC-ND 4.0) License, see https://prosite.expasy.org/prosite_license.html -------------------------------------------------------------------------------- {END}