peroxisomal

Peroxisomes are essential organelles that participate in multiple important metabolic processes, including the β-oxidation of fatty acids, plasmalogen synthesis, and the metabolism of reactive oxygen species (ROS). Peroxiredoxins is overexpressed in breast cancer tissues to a great extent suggesting that they has a proliferative effect and may be related to cancer development or progression. Peroxiredoxin 5 (PRDX5) is a thioredoxin peroxidase that belongs to the atypical 2-Cys class of the TSA ahpC family of peroxiredoxins. PRDX5 is a widely expressed mitochondrial antioxidant enzyme that reduces hydrogen peroxide, alkyl hydroperoxides, and peroxynitrite. In human cells, this enzyme is present in the cytosol, mitochondria, peroxisomes, and nucleus.

PEX11A Protein, Human, Recombinant (mFc) is expressed in HEK293 mammalian cells with mFc tag. The predicted molecular weight is 40 kDa and the accession number is B2R8C6.

Catalyzes the oxidation of L-alpha-hydroxy acids as well as, more slowly, that of L-alpha-amino acids.

ECH1 is a member of the hydratase isomerase superfamily. ECH1 shows high sequence similarity to enoyl-CoA hydratases of several species, particularly within a conserved domain characteristic of these proteins. ECH1 contains a C-terminal peroxisomal targeting sequence and localizes to peroxisomes. The rat ortholog, which localizes to the matrix of both the peroxisome and mitochondria, can isomerize 3-trans, 5-cis-dienoyl-CoA to 2-trans,4-trans-dienoyl-CoA, indicating that it is a delta3,5-delta2,4-dienoyl-CoA isomerase. ECH1 functions in the auxiliary step of the fatty acid beta-oxidation pathway. Expression of the rat gene is induced by peroxisome proliferators.

Catalyzes the desaturation of acyl-CoAs to 2-trans-enoyl-CoAs. First enzyme of the fatty acid beta-oxidation pathway.; Shows highest activity against medium-chain fatty acyl-CoAs and activity decreases with increasing chain length.; Is active against a much broader range of substrates and shows activity towards very long-chain acyl-CoAs. Is twice as active as isoform 1 against 16-hydroxy-palmitoyl-CoA and is 25% more active against 1,16-hexadecanodioyl-CoA.

Binds to the C-terminal PTS1-type tripeptide peroxisomal targeting signal (SKL-type) and plays an essential role in peroxisomal protein import.

Necessary for early peroxisomal biogenesis. Acts both as a cytosolic chaperone and as an import receptor for peroxisomal membrane proteins (PMPs). Binds and stabilizes newly synthesized PMPs in the cytoplasm by interacting with their hydrophobic membrane-spanning domains, and targets them to the peroxisome membrane by binding to the integral membrane protein PEX3. Excludes CDKN2A from the nucleus and prevents its interaction with MDM2, which results in active degradation of TP53. PEX19 Protein, Human, Recombinant (GST) is expressed in E. coli expression system with N-GST tag. The predicted molecular weight is 59.3 kDa and the accession number is P40855.

Receptor that binds peroxisome proliferators such as hypolipidemic drugs and fatty acids. Once activated by a ligand, the receptor binds to a promoter element in the gene for acyl-CoA oxidase and activates its transcription. It therefore controls the peroxisomal beta-oxidation pathway of fatty acids. Key regulator of adipocyte differentiation and glucose homeostasis. May play a role in the regulation of circadian rhythm.

Ligand-activated transcription factor. Receptor that binds peroxisome proliferators such as hypolipidemic drugs and fatty acids. Has a preference for poly-unsaturated fatty acids, such as gamma-linoleic acid and eicosapentanoic acid. Once activated by a ligand, the receptor binds to promoter elements of target genes. Regulates the peroxisomal beta-oxidation pathway of fatty acids. Functions as transcription activator for the acyl-CoA oxidase gene. Decreases expression of NPC1L1 once activated by a ligand.

Hydroxyacid oxidase 1, also known as Glycolate oxidase, HAO1, and GOX1, is a member of the FMN-dependent alpha-hydroxy acid dehydrogenase family. HAO1 GOX1 has 2-hydroxyacid oxidase activity. It is most active on the 2-carbon substrate glycolate, but is also active on 2-hydroxy fatty acids, with high activity towards 2-hydroxy palmitate and 2-hydroxy octanoate. HAO1 GOX1 is a liver-specific peroxisomal enzyme that oxidizes glycolate to glyoxylate with the concomitant production of H2O2. In Hao1 messenger RNA (mRNA), an iron-responsive element (IRE) homologous to the sequence recognized by iron regulatory proteins (IRP), key regulators of iron homeostasis, is present. Mammalian HAO1 GOX1 is a peroxisomal protein and that the C-terminal sequence SKI acts as the targeting signal. Down-regulation of HAO1 GOX1 expression during oxidative stress may provide a mechanism to prevent excessive H2O2 formation in liver peroxisomes and may represent the prototype of a poorly recognized but potentially relevant response to an oxidative injury involving down-regulation of ROS-producing enzymes.

Mitochondrial Fission 1 Protein (FIS1) is a member of the FIS1 family. FIS1 is a single-pass membrane protein and contains one TPR repeat. FIS1 is part of the mitochondrial complex that promotes mitochondrial fission. FIS1 can induce cytochrome C discharge from the mitochondrion to the cytosol, eventually leading to apoptosis. In addition, FIS1 participates in peroxisomal growth and division. The C-terminus of FIS1 is required for mitochondrial or peroxisomal localization, while the N-terminus is necessary for mitochondrial or peroxisomal fission, localization and regulation of the interaction with DNM1L.

Peroxisomal acyl-coenzyme A oxidase 1(ACOX1 or AOX) is the first enzyme of the fatty acid beta-oxidation pathway and belongs to the Acyl-CoA oxidase family. Human liver peroxisomes contain two acyl-CoA oxidases, namely, palmitoyl-CoA oxidase (ACOX1 AOX) and a branched chain acyl-CoA oxidase. The palmitoyl-CoA oxidase (ACOX1 AOX) oxidizes the CoA esters of straight chain fatty acids and prostaglandins and donates electrons directly to molecular oxygen, thereby producing H2O2. Human ACOX1 AOX is a protein of 661-amino acids, including the carboxyl-terminal sequence(Ser-Lys-Leu) known as a minimal peroxisome-targeting signal. Human ACOX1 AOX, the first and rate-limiting enzyme of the peroxisomal β-oxidation pathway, has two isoforms including ACOX1a and ACOX1b, transcribed from a single gene. The human ACOX1b isoform is more effective than the ACOX1a isoform in reversing the Acox1 null phenotype in the mouse partly because of the Substrate utilization differences.

Carnitine octanoyltransferase (CROT or COT), also known as octanoyl-CoA: L-carnitine O-octanoyltransferase, medium-chain long-chain carnitine acyltransferase, and carnitine medium-chain acyltransferase, is a carnitine acyltransferase belonging to the family of transferases, specifically those acyltransferases transferring groups other than aminoacyl groups that catalyzes the reversible transfer of fatty acyl groups between CoA and carnitine. Carnitine octanoyltransferase (CROT or COT) facilitate the transport of medium- and long-chain fatty acids through the peroxisomal and mitochondrial membranes. It is physiologically inhibited by malonyl-CoA. COT also has functions in efficiently converting one of the end products of the peroxisomal beta-oxidation of pristanic acid, 4, 8-dimethylnonanoyl-CoA, to its corresponding carnitine ester.

PMVK is a peroxisomal enzyme that catalyzes the conversion of mevalonate 5-phosphate into mevalonate 5-diphosphate, the fifth reaction of the cholesterol biosynthetic pathway. Studies in rat show that the message level and the enzyme activity of PMVK is regulated by sterol, and that this regulation is coordinated with 3-hydroxy-3-methylglutaryl coenzyme A reductase, the rate-limiting enzyme of cholesterol biosynthesis.

D-Amino-Acid Oxidase (DAO) belongs to the DAMOX DASOX family. DAO is a peroxisomal enzyme which founctions as a homodimer to oxidizes D-amino acids to the corresponding imino acids, producing ammonia and hydrogen peroxide. D-amino-acid oxidase regulates the level of the neuromodulator D-serine in the brain, has a high activity towards D-DOPA and contributes to dopamine synthesis. D-amino-acid oxidase could act as a detoxifying agent which removes D-amino acids accumulated during aging. It also acts on a variety of D-amino acids with a preference for those having small hydrophobic side chains followed by those bearing polar, aromatic, and basic groups.

Catalyzes the conversion of malonyl-CoA to acetyl-CoA. In the fatty acid biosynthesis MCD selectively removes malonyl-CoA and thus assures that methyl-malonyl-CoA is the only chain elongating substrate for fatty acid synthase and that fatty acids with multiple methyl side chains are produced. In peroxisomes it may be involved in degrading intraperoxisomal malonyl-CoA, which is generated by the peroxisomal beta-oxidation of odd chain-length dicarboxylic fatty acids. Plays a role in the metabolic balance between glucose and lipid oxidation in muscle independent of alterations in insulin signaling. May play a role in controlling the extent of ischemic injury by promoting glucose oxidation.