Search results

MMADHC is a mitochondrial protein which takes part in an early step of vitamin B1 2 metabolism. Vitamin B12 (cobalamin) is vital for regular development and existence in humans. Mutations in MMADHC can result in methylmalonic aciduria and homocystinuria type cblD, a cobalamin metabolism syndrome which is characterized by decreased levels of the coenzymes methylcobalamin and adenosylcobalamin.

Though the exact role of MMACHC is unknown, its C-terminal region shows similarity to TonB, which is a bacterial protein involved in energy transduction for cobalamin (vitamin B12) uptake. Therefore, it is suggested that MMACHC may have a role in the binding and intracellular trafficking of cobalamin. MMACHC mutations are linked with methylmalonic aciduria and homocystinuria type cblC. MMACHC is widely expressed, it is expressed at higher level in the fetal liver, however it is also expressed in the spleen, lymph node, thymus and bone marrow. MMACHC is weakly or not expressed in the peripheral blood leukocytes.

MMAB protein catalyzes the last step in the conversion of vitamin B(12) into adenosylcobalamin (AdoCbl), a vitamin B12 containing coenzyme for methylmalonyl-CoA mutase(MCM). Decreased MMAB activity leads to the inherited disorder vitamin B12 dependent methylmalonic aciduria linked to the cblB complementation group.

MCEE catalyzes the interconversion of D- and L-methylmalonyl-CoA throughout the degradation of branched chain amino acids, odd chain-length fatty acids, and other metabolites. MCEE protein deficiency is an autosomal recessive inborn error of amino acid metabolism, involving valine, threonine, isoleucine and methionine. This organic aciduria can appear in the neonatal period with life-threatening metabolic acidosis, hyperammonemia, feeding difficulties, pancytopenia and coma.

MVK is a member of the GHMP kinase family. Mevalonate is a vital mediator, and MVK an important early enzyme, in isoprenoid and sterol synthesis. MVK deficiency can result in gene mutation associated with Mevalonic aciduria, an illness which causes psychomotor retardation, failure to thrive hepatosplenomegaly, anemia and frequent febrile crises. Mutations in this gene also cause hyperimmunoglobulinaemia D and sporadic fever syndrome, in which the person suffers from recurrent episodes of fever related with lymphadenopathy, skin rash, gastrointestinal dismay and arthralgia.

ME2 catalyzes the oxidative decarboxylation of malate to pyruvate, malat + NAD(P)+? pyruvate + CO2 + NAD(P)H+, and is found both in eukaryotic and prokaryotic cells. Three different isoforms of ME are known to be in mammalian tissues: a strictly cytosolic NADP+-dependent enzyme, an NADP+-dependent mitochondriail isoform, and a mitochondrial isoenzyme that is able to use both NAD+ and NADP+ but is more effective with NAD+. The mammalian isoforms size is about 62-64 kDa. A native size of 240,000 Da proposes a tetrameric structure for the active enzyme.
Mitochondrial NAD+-dependent ME 2 activity is seen in tissues that experience many cell divisions, like spleen, thymus, and the basal cells of the small intestinal mucosa. ME2 is also expressed all through the rapid cleavage stages of early Xenopus development. Activity for this isoform is low or nonexistent in brain, muscle, and normal and regenerating liver tissue from rat but was observed in rat adrenal cortex, pigeon and human skeletal muscle, and in heart muscle of some species. In addition, it is expressed in mitochondria of all tumor cells inspected to detain ascites tumors, hepatoma cells, and a variety of other tumors and transformed cell lines.

ALDH6A1 or Methylmalonate-semialdehyde dehydrogenase [acylating], mitochondrial is a mitochondrial methylmalonate semialdehyde dehydrogenase. ALDH6A1 participates in the valine and pyrimidine catabolic pathways. ALDH6A1 catalyzes the irreversible oxidative decarboxylation of malonate, propionyl-CoA and methylmalonate semialdehydes to acetyl. ALDH6A1 deficiency is distinguished by high levels of beta-alanine, 3-hydroxypropionic acid, and the two isomers of 3-amino and 3-hydroxyisobutyric acids in urine organic acids.

ETHE1 is a mitochondrial sulfur dioxygenase involved in catabolism of sulfide that accumulates to toxic levels in ethylmalonic encephalopathy. Mutations of ETHE1 were detected in all the typical ethylmalonic encephalopathy patients analysed, but no ETHE1 mutations were identified in patients presenting with early onset progressive encephalopathy with ethylmalonic aciduria.

Matrix metalloproteinase-2 (MMP-2) is a type IV collagenase, which is involved in endometrial menstrual breakdown, regulation of vascularization and the inflammatory response. MMP-2 contains a number of distinct domains: a prodomain that is cleaved upon activation; a catalytic domain containing the zinc binding site; a fibronectin like domain believed to have a role in substrate targeting; and a carboxyl terminal (hemopexin like) domain containing 2 N-linked glycosylation. The MMP-2 can degrade an extensive array of substrates including type IV, V, VII and X collagens as well as gelatin type I. In addition, MMP-2 interacts with THBS2, TIMP2, Thrombospondin 1, CCL7 and TIMP4. MMP-2 autocatalytic cleavage in the C-terminal generates the anti-angiogenic peptide, PEX. This process seems to be made possible by binding integrinv/beta3. Defects in the MMP-2 are the cause of Torg-Winchester syndrome (TWS), aka multicentric osteolysis nodulosis and arthropathy (MONA).

MMP28, which belongs to the matrix metalloproteinase (MMP) family, takes part in the breakdown of extracellular matrix for both normal physiological processes, such as embryonic development, reproduction and tissue remodeling, and disease processes, like asthma and metastasis. MMP28 is a secreted enzyme which degrades casein. MMP28 participates in tissue homeostasis and in wound repair.

MMP-1 (interstitial collagenase) can break down a wide range of substrates including types I, II, III, VII, VIII, and X collagens as well as L-Selectin, pro-TNF, IGFBP-3, IGFBP-5, casein, gelatin, myelin basic protein, pro-MMP2 and pro-MMP9. A significant function of MMP-1 is the degradation of fibrillar collagens in extracellular matrix remodeling. MMP-1 is expressed in fibroblasts, keratinocytes, endothelial cells, monocytes and macrophages. MMP1 can be divided into a number of distinct domains: a prodomain which is cleaved on activation, a catalytic domain containing the zinc binding site and a short hinge region with a carboxyl terminal domain. MMP1 is part of a cluster of MMP genes which localize to chromosome 11q22.3.

Methionine sulfoxide reductase A (MSRA) is a member of the MsrA Met sulfoxide reductase family. The MSRA enzyme has a vital function as a repair enzyme for proteins which have been inactivated by oxidation. MSRA catalyzes the reversible oxidation-reduction of methionine sulfoxide in proteins to methionine. The three substrates of the MSRA enzyme are peptide-L-methionine, thioredoxin disulfide, and H2O, while its 2 products are peptide-L-methionine (R)-S-oxide and thioredoxin. The MSRA protein is ubiquitous and extremely conserved. Human and animal studies have shown the ultimate levels of expression in kidney and nervous tissue.

MMP-3 enzyme is also known as Stromelysin-1or as Transin-1 which hydrolyzes natural collagen at physiological pH and temperature. It dissolves the intervertebral nucleus pulposus and annulus fibrosus of Herniated Lumbar Intervertebral Disk . MMP-3 hydrolyzes components of the extracellular matrix like proteoglycan, laminin, fibronectin, gelatin and collagen types III, IV and IX. It also activates pro-MMP-9 and pro-MMP-8 and superactivates plasmin activated MMP-1. MMP-3 is secreted as a latent proenzyme and is activated by a variety of proteinases, e.g. plasmin, trypsin, chymotrypsin, cathepsin G or human neutrophil elastase. MMP-3 was found to be capable of activating the precursor of IL1-beta.

Matrix metalloproteinase-7 (MMP-7) also known as matrilysin and PUMP (EC 3.4.24.23) cleaves a number of substrates including collagen types IV and X, elastin, fibronectin, gelatin, laminin and proteoglycans. MMP-7 is closely related to the stromelysin family members but is encoded by a different gene. MMP-7 is the smallest of all the MMPs consisting of a pro-peptide domain and a catalytic domain. It lacks the hemopexin-like domain common to other members of the MMPs. MMP-7 is secreted as a 28 kDa proenzyme and can be activated in vitro by organomercurials and trypsin and in vivo by MMP-3 to a 18 kDa active MMP-7 enzyme. Once activated, MMP-7 can activate pro-MMP-1 and pro-MMP-9 but not pro-MMP-2. MMP-7 is widely expressed having been reported in elevated levels in cycling endometrium as well as in colorectal cancers and adenomas, hepatocellular carcinomas, rectal carcinomas, and approximately 50% of gliomas.

Diphosphomevalonate decarboxylase (MVD) catalyzes the conversion of mevalonate pyrophosphate into isopentenyl pyrophosphate in one of the early steps in cholesterol biosynthesis. MVD decarboxylates and dehydrates its substrate while hydrolyzing ATP. MVD is expressed in the heart, skeletal muscle, lung, liver, brain, pancreas, kidney and placenta.

MBP is a major component of the myelin sheath of oligodendrocytes and Schwann cells in the nervous system, although, MBP-related transcripts are also present in the bone marrow and the immune system. These mRNAs emerge from the long MBP gene which holds three additional exons located upstream of the classic MBP exons. The Golli mRNAs contain three exons unique to Golli-MBP, spliced in-frame to one or more MBP exons. The second family of transcripts contains only MBP exons and produces the well characterized myelin basic proteins. MBP transcription unit is an essential part of the Golli transcription unit and the arrangement is important for the function and/or regulation of these genes.

Monoamine Oxidase A, also known as MAOA catalyzes the oxidative deamination of biogenic as well as xenobiotic amines and has significant functions in the metabolism of neuroactive and vasoactive amines in the central nervous system as well as peripheral tissues. Mutation in MAOA results in Brunner syndrome; in addition MAOA has also been linked with a diversity of other psychiatric disorders, which includes antisocial behavior. MAOA preferentially oxidizes biogenic amines such as 5-hydroxytryptamine (5-HT).

MDS1 is a transcriptional regulator and oncoprotein which takes part in hematopoiesis, development, cell differentiation, apoptosis and proliferation. MDS1 is able to interact with CTBP1, SMAD3, CREBBP, KAT2B, MAPK8, and MAPK9. Overexpression, as a result of translocation with the AML1 gene, is known to cause leukemia. A number of transcript variants encoding several different isoforms were found.

Anti-Mullerian Hormone also known as AMH is a member of the TGF-beta family. AMH is a glycoprotein which is produced by the Sertoli cells of the testis, causes regression of the Muellerian duct. AMH inhibits the growth of tumors derived from tissues of Muellerian duct origin. Moreover, AMH participates in Leydig cell differentiation and function in addition to follicular development in adult females.

Porphobilinogen deaminase (HMBS) belongs to the hydroxymethylbilane synthase superfamily. HMBS is a cytoplasmic enzyme found in the heme synthesis pathway. HMBS is the 3rd enzyme of the heme biosynthetic pathway and catalyzes the head to tail condensation of 4 porphobilinogen molecules into the linear hydroxymethylbilane. HMBS gene mutations cause errors in pyrrole metabolism which in turn lead to the autosomal dominant disease acute intermittent porphyria.

Maltose Binding Protein is a member of the maltose/maltodextrin system of E.Coli, which is accountable for the uptake and efficient catabolism of maltodextrins. The maltose/maltodextrin is a complex regulatory and transport system involving many proteins and protein complexes.
MBP elevates the yield of its fusion partner in many cases and is often able to promote the solubility of polypeptides to which it is fused.

Melanoma Antigen Family A 8, also known as MAGEA8 belongs to the MAGE gene family, which includes twelve known genes, of which six are expressed in tumors. Furthermore, the MAGE genes were at first isolated from different kinds of tumors, and according to their virtually exclusive tumor-specific expression in adult tissues, they have been used as targets for cancer immunotherapy.

DNA-3-methyladenine glycosylase (MPG) is a member of the DNA glycosylase MPG family. MPG initiates base excision repair in DNA by removing a wide variety of alkylated, deaminated, and lipid peroxidation-induced purine adducts.

MDH1 catalyzes the reversible oxidation of malate to oxaloacetate, using the NAD/NADH cofactor system in the citric acid cycle. MDH1 is abundantly found in the cytoplasm and is involved in the malate-aspartate shuttle that functions in the metabolic coordination between cytosol and mitochondria. MDH1 regulates p53-dependent cell-cycle arrest and apoptosis in response to glucose deprivation.