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AK1 is a small ubiquitous enzyme which is essential for maintenance and cell growth. It is involved in the regulation of adenine nucleotide composition within a cell by catalyzing the reversible transfer of the terminal phosphate group between ATP and AMP. The AK1 protein is found in the cytosol of skeletal muscle, brain and erythrocytes. Defects in the AK1 gene are the cause of a form of hemolytic anemia.

ALDH2 is part of the aldehyde dehydrogenase family of proteins which catalyze the chemical transformation from acetaldehyde to acetic acid. ALDH2 is the second enzyme of the major oxidative pathway of alcohol metabolism. ALDH2 has 2 major liver isoforms: cytosolic and mitochondrial, which differ by their electrophoretic mobilities, kinetic properties, and subcellular localizations. Nearly all Caucasians have 2 major isozymes, whereas roughly 50% of Orientals have only the cytosolic isozyme, omitting the mitochondrial isozyme. The extremely higher rate of acute alcohol intoxication with Orientals compared to Caucasians is due to the fact of the absence of mitochondrial isozyme. ALDH2 has a low Km for acetaldehydes, and is localized in mitochondrial matrix.

NADH dehydrogenase [ubiquinone] 1 alpha subcomplex assembly factor 4 (NDUFAF4) is involved in the compilation of mitochondrial NADH: ubiquinone oxidoreductase complex (complex I). In addition, NDUFAF4 is involved in cell proliferation and survival of hormone-dependent tumor cells. NDUFAF4 may also be a regulator of breast tumor cell invasion. NDUFAF4 gene mutations cause the mitochondrial complex I deficiency.

Aminomethyltransferase, mitochondrial isoform 1 (AMT) is a component of the glycine cleavage system termed T-protein. AMT reversibly catalyzes the degradation of the aminomethyl moiety of glycine attached to the lipoate cofactor of H-protein, leading to the production of ammonia, 5,10-methylenetetrahydrofolate, and dihydrolipoate-bearing H-protein in the presence of tetrahydrofolate.

MAT1A catalyzes a two-step reaction that involves the transfer of the adenosyl moiety of ATP to methionine to form S-adenosylmethionine and tripolyphosphate, which is subsequently cleaved to PPi and Pi. S-adenosylmethionine is the source of methyl groups for most biological methylations. MAT1A is found as a homotetramer (MAT I) or a homodimer (MAT III) whereas a third form, MAT II (gamma), is encoded by the MAT2A gene. Mutations in MAT1A gene are associated with methionine adenosyltransferase deficiency. MAT1A expression also correlates with a differentiated phenotype, whereas liver cells expressing MAT2A present a dedifferentiated phenotype and lowered AdoMet synthesis. Likewise, NFκB and TNFα cause a switch from MAT1A to MAT2A expression in human hepatocellular carcinoma (HCC), which facilitates cancer cell growth.

Aminoacyl-tRNA synthetases are a class of enzymes which charge tRNAs with their cognate amino acids. Asparaginyl-tRNA synthetase (NARS) is localized to the cytoplasm and is a member of the class II family of tRNA synthetases. The N-terminal domain characterizes the signature sequence for the eukaryotic asparaginyl-tRNA synthetases.

Ectonucleoside Triphosphate Diphosphohydrolase 3, also known as ENTPD3, which owns a threefold preference for the hydrolysis of ATP over ADP is similar to E-type nucleotidases (NTPases). ENTPD3 is a protein coding gene which contains four apyrase-conserved areas which is characteristic of NTPases.

ATPase inhibitory factor 1 (ATPIF1) attaches to the C-terminal region of a beta subunit of the F1-ATPase at low pH values and, through interference of the beta and gamma subunit interaction, ATPIF1 controls the activity of the F1 (the hydrophilic catalytic core), F0 (the membrane embedded protein channel) ATPase. ATPIF1 overexpression in a number of human carcinomas additionally reinforces its participation in oncogenesis and offers insight into the transformed metabolism of cancer cells, including the reprogramming of energy metabolism in relation to glycolysis. Endogenous F1F(o)-ATPase inhibitor curbing ATP depletion when the mitochondrial membrane potential drops below a threshold and the F1F(o)-ATP synthase begins hydrolyzing ATP to pump protons out of the mitochondrial matrix.

PTGES3 takes part as a cochaperone and is involved in signal transduction.
PTGES3 is a molecular chaperone that localizes to genomic response elements in a hormone-dependent manner and disrupts receptor-mediated transcriptional activation, by promoting disassembly of transcriptional regulatory complexess. PTGES3 is necessary for appropriate functioning of the glucocorticoid and other steroid receptors.
PTGES3 localizes to genomic response elements in a hormone-dependent method and disrupts receptor-mediated transcriptional activation, by promoting disassembly of transcriptional regulatory complexes.

PRPS1 catalyzes the synthesis of phosphoribosylpyrophosphate (PRPP) that is essential for nucleotide synthesis. PRPS1 catalyzes the phosphoribosylation of ribose 5-phosphate to 5-phosphoribosyl-1-pyrophosphate, which is essential for purine metabolism and nucleotide biosynthesis. Defects in PRPS1 result in phosphoribosylpyrophosphate synthetase superactivity, Charcot-Marie-Tooth disease X-linked recessive type 5 and Arts Syndrome.

Spermidine/Spermine N1-Acetyltransferase 2, also known as SAT2 catalyzes the acetylation of polyamines (Acetyl-CoA + an alkane-alpha,omega-diamine = CoA + an N-acetyldiamine).

Histidine NADH Dehydrogenase Fe-S Protein 5 (NDUFS5) belongs to the NADH dehydrogenase (ubiquinone) iron-sulfur protein family. NDUFS5 is a subunit of the mitochondrial membrane respiratory chain NADH dehydrogenase (Complex I), which doesn’t take part in catalysis. Complex I is transferring the electrons from NADH to the respiratory chain.

Paraoxonase-1 or PON1 is part of the paraoxonase group of proteins. PON1 is an enzyme, responsible to the toxic metabolites of a different of organophosphorus insecticides hydrolyzation. Furthermore, PON1 is a dominant anti-atherosclerotic part of HDL. The enzyme needs PPAR-gamma for activation, leading to synthesis and release of paraoxonase 1 from the liver tissue, resulting in atherosclerosis reduction. PON1 has many qualities for atheroprotective through inflammatory lipid peroxides metabolism. This enzyme can hydrolyze a large number of substrates, for example cyclic carbonates, lactones, nerve gases etc.

SAT-1 is a member the acetyltransferase family, and is a rate-limiting enzyme in the catabolic pathway of polyamine metabolism. SAT1 catalyzes the acetylation of spermidine and spermine, and is involved in the regulation of the intracellular concentration of polyamines and their transport out of cells. Therefore, SAT-1’s role is essential in polyamine homoeostasis, given that acetylated products are either excreted from the cell or oxidized by acetylpolyamine oxidase. Increased SAT1 activity causes variety of other effects which include pancreatic cells death, obstruction of regenerative tissue growth, behavioral changes, keratosis follicularis spinulosa decalvans (KFSD), and hair loss.
Defects in the SAT1 gene are linked to KFSD (keratosis follicularis spinulosa decalvans), which is a rare X-linked disorder affecting the skin and the eye. The KFSD affected men show thickening of the skin of the neck, ears, and extremities, particularly the palms and soles, loss of eyebrows, eyelashes and beard, thickening of the eyelids with blepharitis and ectropion, and corneal degeneration. Even though the majority of the affected families are compatible with an X-linked inheritance, KFSD are found to be clinically and genetically heterogeneous.

Alanyl-tRNA synthetase is a member of the aminoacyl-tRNA synthetase family, key enzymes of protein biosynthesis which charge tRNA molecules with the respective amino acids. This 108 kDa protein is an autoantigen recognized by PL-12 antibodies which occur in a subset of patients with polymyositis and dermatomyositis. Preliminary data suggest that epitope spreading occurs in the autoimmune PL-12 response such that even antibodies to an isolated alanyl-tRNA molecule can develop.

Fucosyltransferase 7 (FUT7) is a golgi stack membrane protein which is involved in the creation of sialyl-Lewis X antigens. The FUT7 protein leads the synthesis of the E-selectin-binding sialyl-Lewis X moiety. FUT7 catalyzes alpha-1,3 glycosidic linkages involved in the expression of sialyl Lewis X antigens.

Phosphoribosyl Pyrophosphate Synthetase 2, also known as PRPS2 is a member of the ribose-phosphate pyrophosphokinase family. PRPS2 catalyzes the synthesis of 5-phosphoribosyl 1-pyrophosphate from ATP and D-ribose 5-phosphate.

MAT2A is an important enzyme in cellular metabolism and catalyzes the formation of S-adenosylmethionine (SAMe) from L-methionine and ATP. MAT2A is expressed in extrahepatic tissues. In liver, MAT2A expression associates with growth, dedifferentiation, and cancer. NF-kappa B and AP-1 are necessary for basal MAT2A expression in HepG2 cells and mediate the increase in MAT2A expression in response to TNF-alpha. Up-regulation of MAT2A provides growth improvement and s-adenosylmethionine and methylthioadenosine thus can block mitogenic signaling in colon cancer cells. Lower expression of both MAT2A and MAT2beta and interfere with leptin signaling in liver cancer cells.

MRPL28 is found in a variety of normal tissues such as spleen, testis, thymus, liver, kidney, brain, adrenal, lung and retinal tissue. 39S ribosomal protein L28, mitochondrial (MRPL28), is a part of the ribosomal protein L28P family. Mammalian mitochondrial ribosomal proteins encoded by nuclear genes and helps in protein synthesis within the mitochondrion. Mitochondrial ribosomes (mitoribosomes) consist of a small 28S subunit and a large 39S subunit. MRPL28 is an important therapeutic reagent for HLA-A24 (A24) patients since this antigen is distinguished by tumor-infiltrating lymphocyte (TIL) 1290, which targets the A24 serotype.

GGPS1 is PART of the prenyltransferase family. GGPS1 is widely expressed in testis, heart and skeletal muscle, GGPS1 is localized in the cytoplasm and catalyzes the formation of geranylgeranyl pyrophosphate, a precursor of geranylgeranylated proteins and carotenoids. GGPS1 is a significant enzyme that is responsible for the C20-prenylation of proteins and for the regulation of a nuclear hormone receptor.

Phosphoserine aminotransferase (PSAT1) catalyzes the conversion of 3-phosphohydroxypyruvate into 3-phosphoserine which is dephosphorylated consequently by phosphoserine phosphatase to form L-serine. PSAT1 is probably a phosphoserine aminotransferase, based on similarity to proteins in mouse, rabbit, and Drosophila. PSAT1 is expressed at high levels in the brain, liver, kidney and pancreas, and very weakly expressed in the thymus, prostate, testis and colon. Defects in the PSAT1 gene are the cause of phosphoserine aminotransferase deficiency (PSATD). PSATD is distinguished biochemically by low plasma and cerebrospinal fluid concentrations of serine and glycine and clinically by intractable seizures, acquired microcephaly, hypertonia, and psychomotor retardation.

Aminoacyl-tRNA synthetases are a class of enzymes which charge tRNAs with their cognate amino acids. Asparaginyl-tRNA synthetase (NARS) is localized to the cytoplasm and is a member of the class II family of tRNA synthetases. The N-terminal domain characterizes the signature sequence for the eukaryotic asparaginyl-tRNA synthetases.

ASS1 is involved in the urea cycle, which is a sequence of chemical reactions that is localized in liver cells. The urea cycle processes excess nitrogen that is generated as the body uses proteins. The surplus nitrogen is used to create a molecule called urea, which is excreted from the body in urine.

Translocase of Outer Mitochondrial Membrane 34 (TOMM34) which is found in the cytoplasm and sometimes associated with the outer mitochondrial membrane is involved in the import of precursor proteins into mitochondria. TOMM34 has a chaperone-like activity, binding the mature portion of unfolded proteins and aiding their import into mitochondria. TOMM34 has a weak ATPase activity and contains 6 TPR repeats.