PMID-sentid Pub_year Sent_text comp_official_name comp_offsetprotein_name organism prot_offset 8479601-2 1993 Since SAM causes PD-like symptoms in rodents, the decreased efficacy of chronic L-dopa administered to PD patients may result from a rebound increase in SAM via methionine adenosyl transferase (MAT), which produces SAM from methionine and ATP. Methionine 161-171 methionine adenosyltransferase 1A Homo sapiens 194-197 33273451-6 2020 The conversion of key enzymes of methionine metabolism methionine adenosyltransferase (MAT) 1 A and MAT2A/MAT2B is closely related to fibrosis and hepatocellular carcinoma. Methionine 33-43 methionine adenosyltransferase 1A Homo sapiens 55-95 1587846-8 1992 The Km for L-methionine for enzyme from resting peripheral blood mononuclear cells was 19-23 microM, which is 3-8-fold higher than purified MAT from fresh leukemic cells or enzyme from Jurkat cells, both of which have a Km of 3.5-3.8 microM. Methionine 11-23 methionine adenosyltransferase 1A Homo sapiens 140-143 35159219-1 2022 Alterations of methionine cycle in steatohepatitis, cirrhosis, and hepatocellular carcinoma induce MAT1A decrease and MAT2A increase expressions with the consequent decrease of S-adenosyl-L-methionine (SAM). Methionine 15-25 methionine adenosyltransferase 1A Homo sapiens 99-104 3339126-8 1988 This abnormally low rate is due not to a decreased flux through the primarily defective enzyme, MAT, since SAM is produced at an essentially normal rate of 18 mmol/d, but rather to a rate of homocysteine methylation which is abnormally high in the face of the very elevated methionine concentrations demonstrated in this patient. Methionine 274-284 methionine adenosyltransferase 1A Homo sapiens 96-99 35008908-0 2022 Downregulation of Methionine Cycle Genes MAT1A and GNMT Enriches Protein-Associated Translation Process and Worsens Hepatocellular Carcinoma Prognosis. Methionine 18-28 methionine adenosyltransferase 1A Homo sapiens 41-46 35008908-11 2022 This is the first study demonstrated that MAT1A and GNMT, the 2 key enzymes involved in methionine cycle, could attenuate the function of ribosome translation. Methionine 88-98 methionine adenosyltransferase 1A Homo sapiens 42-47 30226369-7 2018 Proteomics analysis of Nnmt-interacting proteins in the liver identified Bhmt, Mat1a, and Ahcy, all components of the methionine cycle, and functional experiments showed that mutant Nnmt increased the level of remethylation of homocysteine to SAM. Methionine 118-128 methionine adenosyltransferase 1A Homo sapiens 79-84 31851615-7 2020 Results and conclusions MAT I/III deficiency is a common reason for Met elevation in neonatal screening by tandem mass spectrometry (MS/MS), which needs long-term follow-up except for these patients with explicitly benign mutations. Methionine 68-71 methionine adenosyltransferase 1A Homo sapiens 24-33 33000151-1 2020 Metabolism of excess methionine (Met) to homocysteine (Hcy) by transmethylation is facilitated by the expression of methionine adenosyltransferase (MAT) I/III and glycine N-methyltransferase (GNMT) in liver, and a lack of either enzyme results in hypermethioninemia despite normal concentrations of MATII and methyltransferases other than GNMT. Methionine 21-31 methionine adenosyltransferase 1A Homo sapiens 116-158 31552788-1 2020 S-adenosylmethionine (SAM), biosynthesis from methionine and ATP, is markedly decreased in hepatocellularular carcinoma (HCC) for a diminution in ATP levels, and the down regulation of the liver specific MAT1a enzyme. Methionine 10-20 methionine adenosyltransferase 1A Homo sapiens 204-209 31641591-2 2019 Newborn screening by MS/MS on dried blood spot samples (DBS) has one of its items in methionine levels: the knowledge of this parameter allows the identification of infant affected by homocystinuria (cystathionine beta-synthase, CBS, deficiency) but can also lead, as side effect, to identify cases of methionine adenosyltransferase (MAT) type I/III deficiency. Methionine 85-95 methionine adenosyltransferase 1A Homo sapiens 334-337 24649856-1 2014 UNLABELLED: Methionine adenosyltransferase (MAT) is a family of enzymes that utilizes ATP and methionine to produce S-adenosylmethionine (AdoMet), the most crucial methyl donor in the biological methylation of biomolecules and bioactive natural products. Methionine 94-104 methionine adenosyltransferase 1A Homo sapiens 12-42 26289392-2 2015 MAT1A encodes the subunit that forms two methionine adenosyltransferase isoenzymes, tetrameric MAT I and dimeric MAT III, that catalyze the conversion of methionine and ATP to S-adenosylmethionine (AdoMet). Methionine 41-51 methionine adenosyltransferase 1A Homo sapiens 0-5 26289392-2 2015 MAT1A encodes the subunit that forms two methionine adenosyltransferase isoenzymes, tetrameric MAT I and dimeric MAT III, that catalyze the conversion of methionine and ATP to S-adenosylmethionine (AdoMet). Methionine 41-51 methionine adenosyltransferase 1A Homo sapiens 95-100 26289392-2 2015 MAT1A encodes the subunit that forms two methionine adenosyltransferase isoenzymes, tetrameric MAT I and dimeric MAT III, that catalyze the conversion of methionine and ATP to S-adenosylmethionine (AdoMet). Methionine 41-51 methionine adenosyltransferase 1A Homo sapiens 117-120 26289392-4 2015 Individuals, with hypermethioninemia due to one of the MAT1A mutations that in heterozygotes cause relatively mild and clinically benign hypermethioninemia are currently often being flagged in screening programs measuring methionine elevation to identify newborns with defective cystathionine beta-synthase activity. Methionine 23-33 methionine adenosyltransferase 1A Homo sapiens 55-60 24649856-1 2014 UNLABELLED: Methionine adenosyltransferase (MAT) is a family of enzymes that utilizes ATP and methionine to produce S-adenosylmethionine (AdoMet), the most crucial methyl donor in the biological methylation of biomolecules and bioactive natural products. Methionine 94-104 methionine adenosyltransferase 1A Homo sapiens 44-47 24649856-2 2014 Here, we report that the MAT from Sulfolobus solfataricus (sMAT), an enzyme from a poorly explored class of the MAT family, has the ability to produce a range of differentially alkylated AdoMet analogs in the presence of non-native methionine analogs and ATP. Methionine 232-242 methionine adenosyltransferase 1A Homo sapiens 25-28 24649856-2 2014 Here, we report that the MAT from Sulfolobus solfataricus (sMAT), an enzyme from a poorly explored class of the MAT family, has the ability to produce a range of differentially alkylated AdoMet analogs in the presence of non-native methionine analogs and ATP. Methionine 232-242 methionine adenosyltransferase 1A Homo sapiens 60-63 23430947-2 2012 One case was confirmed to be a deficiency of cystathionine beta-synthase and 20 cases were confirmed by MAT1A gene analysis to have an elevation of methionine due to MAT I/III deficiency, which indicates an incidence for this condition of 1/26,000. Methionine 148-158 methionine adenosyltransferase 1A Homo sapiens 104-109 24445979-10 2014 CONCLUSION: These cases show that individuals with even single changes in the MAT1A gene may have elevations in methionine identified by newborn screening, which may persist for months after birth without any clinical consequences. Methionine 112-122 methionine adenosyltransferase 1A Homo sapiens 78-83 23425511-1 2013 MAT (methionine adenosyltransferase) utilizes L-methionine and ATP to form SAM (S-adenosylmethionine), the principal methyl donor in biological methylation. Methionine 46-58 methionine adenosyltransferase 1A Homo sapiens 5-35 21185701-2 2012 The S-adenosylmethionine synthetase type-1 (MAT1A), an essential enzyme in the conversion of methionine to S-adenosylmethionine, plays a key role in homocysteine metabolism. Methionine 14-24 methionine adenosyltransferase 1A Homo sapiens 44-49 22724053-14 2012 The MAT1A genetic polymorphism may impact plasma SAM concentrations in men with low plasma methionine concentrations. Methionine 91-101 methionine adenosyltransferase 1A Homo sapiens 4-9 27508177-4 2014 Alterations in the methylation of the promoter of methyl adenosyltransferase MAT1A and MAT2A genes in HCC result in decreased S-adenosylmethionine levels, global DNA hypomethylation, and deregulation of signal transduction pathways linked to methionine metabolism and methyl adenosyltransferases activity. Methionine 136-146 methionine adenosyltransferase 1A Homo sapiens 77-82 24128087-4 2014 SAM is generated from adenosine triphosphate (ATP) and methionine by methionine adenosyltransferase (MAT), a redox-sensitive enzyme in the SAM cycle. Methionine 55-65 methionine adenosyltransferase 1A Homo sapiens 69-99 24128087-4 2014 SAM is generated from adenosine triphosphate (ATP) and methionine by methionine adenosyltransferase (MAT), a redox-sensitive enzyme in the SAM cycle. Methionine 55-65 methionine adenosyltransferase 1A Homo sapiens 101-104 22807109-0 2012 Human liver methionine cycle: MAT1A and GNMT gene resequencing, functional genomics, and hepatic genotype-phenotype correlation. Methionine 12-22 methionine adenosyltransferase 1A Homo sapiens 30-35 22807109-8 2012 Correlation analyses among hepatic protein levels for methionine cycle enzymes showed significant correlations between GNMT and MAT1A (p = 1.5 x 10(-3)) and between GNMT and betaine homocysteine methyltransferase (p = 1.6 x 10(-7)). Methionine 54-64 methionine adenosyltransferase 1A Homo sapiens 128-133 15963701-2 2005 In this study, the metabolic consequences of the pathological changes associated with the key pathway enzymes, methionine adenosyl transferase (MAT), glycine N-methyl transferase (GNMT) and cystathionine beta-synthase (CBS) as well as an activation of polyamine metabolism, were analyzed using a simple mathematical model describing methionine metabolism in liver. Methionine 111-121 methionine adenosyltransferase 1A Homo sapiens 144-147 16413417-11 2006 Increased flux of (13)C-labeled methionine to S-adenosylhomocysteine (SAH) in A549 demonstrated that SAM"s methyl group was utilized, and increased formation of cystathionine indicated that at least part of SAM generated was directed toward cysteine/GSH in the transsulfuration pathway. Methionine 32-42 methionine adenosyltransferase 1A Homo sapiens 101-106 20675163-3 2010 During the past 15years 28 MAT1A mutations have been described in patients with elevated plasma methionines, total homocysteines at most only moderately elevated, and normal levels of tyrosine and other aminoacids. Methionine 96-107 methionine adenosyltransferase 1A Homo sapiens 27-32 16340382-4 2005 SAM levels were significantly reduced in levodopa-treated PD patients, but they showed increased enzyme methionine adenosyl transferase (MAT) activity, which induces SAM synthesis from methionine (MET). Methionine 104-114 methionine adenosyltransferase 1A Homo sapiens 137-140 15963701-5 2005 Application of the characteristics of transformed hepatocytes to our model, i.e., substitution of the MAT I/III isozyme by MAT II, loss of GNMT activity and activation of polyamine biosynthesis, leads to the prediction of a significantly different dependence of methionine metabolism on methionine concentrations. Methionine 262-272 methionine adenosyltransferase 1A Homo sapiens 102-111 15963701-5 2005 Application of the characteristics of transformed hepatocytes to our model, i.e., substitution of the MAT I/III isozyme by MAT II, loss of GNMT activity and activation of polyamine biosynthesis, leads to the prediction of a significantly different dependence of methionine metabolism on methionine concentrations. Methionine 287-297 methionine adenosyltransferase 1A Homo sapiens 102-111 10567242-1 1999 S-Adenosylmethionine (AdoMet) synthetase (SAMS: EC 2.5.1.6) catalyses the formation of AdoMet from methionine and ATP. Methionine 10-20 methionine adenosyltransferase 1A Homo sapiens 42-46 12660248-4 2003 In l-methionine-deficient cells, MAT2A gene expression is rapidly induced, and methionine adenosyltransferase activity is increased. Methionine 3-15 methionine adenosyltransferase 1A Homo sapiens 79-109 12145770-1 2002 Abnormal elevation of plasma methionine may result from several different genetic abnormalities, including deficiency of cystathionine beta-synthase (CBS) or of the isoenzymes of methionine adenosyltransferase (MAT) I and III expressed solely in nonfetal liver (MAT I/III deficiency). Methionine 29-39 methionine adenosyltransferase 1A Homo sapiens 222-225 11145114-6 2000 A low plasma AdoMet concentration in the presence of an elevated methionine provides a useful diagnostic tool that pinpoints the cause of a case of hypermethioninemia as defective MAT I/III activity. Methionine 65-75 methionine adenosyltransferase 1A Homo sapiens 180-189 10677294-5 2000 Two patients-a compound heterozygote for truncating and severely inactivating missense mutations and a homozygote for an aberrant splicing MAT1A mutation-have plasma methionine in the 1,226-1,870 microM range (normal 5-35 microM) and manifest abnormalities of the brain gray matter or signs of brain demyelination. Methionine 166-176 methionine adenosyltransferase 1A Homo sapiens 139-144 10674710-1 2000 Hepatic methionine adenosyltransferase (MAT) deficiency is caused by mutations in the human MAT1A gene that abolish or reduce hepatic MAT activity that catalyzes the synthesis of S-adenosylmethionine from methionine and ATP. Methionine 8-18 methionine adenosyltransferase 1A Homo sapiens 92-97 10955733-1 2000 Methionine adenosyltransferase (MAT) catalyzes the synthesis of S-adenosylmethionine (AdoMet) from ATP and L-methionine. Methionine 107-119 methionine adenosyltransferase 1A Homo sapiens 0-30 10955733-1 2000 Methionine adenosyltransferase (MAT) catalyzes the synthesis of S-adenosylmethionine (AdoMet) from ATP and L-methionine. Methionine 107-119 methionine adenosyltransferase 1A Homo sapiens 32-35 10620770-7 2000 We assume that methionine reduces the level of one or several adenine nucleotides by a SAMS-mediated mechanism. Methionine 15-25 methionine adenosyltransferase 1A Homo sapiens 87-91 10415148-4 1999 In comparison with controls, the male group presented a 33% higher V(max) (P < 0.05) and a 41% decrease in the affinity of MAT for methionine (K(m), P < 0.05). Methionine 131-141 methionine adenosyltransferase 1A Homo sapiens 123-126 9337154-6 1997 Our results suggest that H2O2-induced MAT inactivation might be the cause of reduced MAT activity and abnormal methionine metabolism observed in patients with alcoholic liver disease. Methionine 111-121 methionine adenosyltransferase 1A Homo sapiens 38-41 10216131-8 1999 Because liver-specific MAT exhibits a much higher Km for methionine (mmol/L) than non-liver-specific MAT ( approximately 10 micromol/L), MAT activity was decreased at 5 mmol/L but increased at 20 micromol/L methionine concentration. Methionine 57-67 methionine adenosyltransferase 1A Homo sapiens 23-26 10216131-8 1999 Because liver-specific MAT exhibits a much higher Km for methionine (mmol/L) than non-liver-specific MAT ( approximately 10 micromol/L), MAT activity was decreased at 5 mmol/L but increased at 20 micromol/L methionine concentration. Methionine 207-217 methionine adenosyltransferase 1A Homo sapiens 23-26 9755242-2 1998 Hepatic MAT plays an essential role in the metabolism of methionine, converting this amino acid into S-adenosylmethionine. Methionine 57-67 methionine adenosyltransferase 1A Homo sapiens 8-11 9337154-1 1997 Liver methionine adenosyltransferase (MAT) plays a critical role in the metabolism of methionine converting this amino acid, in the presence of ATP, into S-adenosylmethionine. Methionine 6-16 methionine adenosyltransferase 1A Homo sapiens 38-41 8903381-3 1996 SAMS isoenzymes differ greatly in kinetic parameters and sensitivity to inhibition by methionine analogs. Methionine 86-96 methionine adenosyltransferase 1A Homo sapiens 0-4 9217094-4 1997 The catalytic activity of MAT was increased by 30% in patients compared to controls, with the Vmax for methionine being 17.9 +/- 3.7 and 13.9 +/- 2.2 pmol/mg/h, respectively. Methionine 103-113 methionine adenosyltransferase 1A Homo sapiens 26-29 8903381-9 1996 As a result of the change in SAMS expression, SAMS activity was higher in HepG2 and HuH-7 cells at physiologically relevant methionine concentrations but lower at high (mmol/L) methionine concentrations than rat hepatocytes. Methionine 124-134 methionine adenosyltransferase 1A Homo sapiens 29-33 8903381-9 1996 As a result of the change in SAMS expression, SAMS activity was higher in HepG2 and HuH-7 cells at physiologically relevant methionine concentrations but lower at high (mmol/L) methionine concentrations than rat hepatocytes. Methionine 124-134 methionine adenosyltransferase 1A Homo sapiens 46-50 8903381-9 1996 As a result of the change in SAMS expression, SAMS activity was higher in HepG2 and HuH-7 cells at physiologically relevant methionine concentrations but lower at high (mmol/L) methionine concentrations than rat hepatocytes. Methionine 177-187 methionine adenosyltransferase 1A Homo sapiens 29-33 8903381-9 1996 As a result of the change in SAMS expression, SAMS activity was higher in HepG2 and HuH-7 cells at physiologically relevant methionine concentrations but lower at high (mmol/L) methionine concentrations than rat hepatocytes. Methionine 177-187 methionine adenosyltransferase 1A Homo sapiens 46-50 7894257-4 1994 The apparent values of MAT Km and Vmax in the parietal cortex were 11.41 +/- 3.51 microM methionine and 25.72 +/- 3.90 nmol/mg protein/h, respectively. Methionine 89-99 methionine adenosyltransferase 1A Homo sapiens 23-26