High impact information on Fh1

• In conjunction with NOS, citric acid cycle enzymes that covert fumarate to oxaloacetate (fumarase and malate dehydrogenase) and oxaloacetate to aspartate (aspartate transaminase), AS and AL form a novel arginine-citrulline cycle that enables high output NO production by cells [1].
• The aminotransferase in these hetero-enzyme complexes could be supplied with oxalacetate because binding of aminotransferase to the high molecular weight enzymes can enhance binding of malate dehydrogenase, and binding of both malate dehydrogenase and the aminotransferase facilitated binding of fumarase [2].
• The total amino acid sequence of the mitochondrial fumarase also contained all the sequences of 14 proteolytic peptides obtained from the cytosolic fumarase, indicating that the amino acid sequences of these two isozymes are identical [3].
• Thus, this reading frame was concluded to encode the precursor of mitochondrial fumarase [3].
• By use of anti-cytosolic fumarase antibody, a cDNA clone was isolated from a rat liver cDNA library in the expression vector lambda gt11 and in the pBR 322 vector [3].

Biological context of Fh1

• The amino acid sequence predicted from the nucleotide sequence contained all the amino acid sequences of 12 proteolytic polypeptides produced by digestion of purified mitochondrial fumarase with V8 protease [3].
• The open reading frame encoded a polypeptide of 507-amino acid residues (predicted Mr = 54,462), which contained an additional sequence of 41-amino acid residues on the NH2 terminus of the mitochondrial mature fumarase (the presequence) [3].
• Backcross progenies showed the expected 1:1 segregation ratio, and there is evidence that Mgd1 is linked to Pep3 and Fh1 on chromosome 13 [4].
• The sedimentable fraction also contained four other presumably soluble Krebs tricarboxylic acid cycle enzymes: aconitase, NAD+-isocitrate dehydrogenase, fumarase, and malate dehydrogenase [5].
• The oxygen-consumption rates and the activities of fumarase and beta-hydroxyacyl-CoA dehydrogenase were compared in mitochondria isolated from fetal- and neonatal-rat kidney [6].

Anatomical context of Fh1

• The following observations strongly suggested that the 35S-labeled mature size fumarase in mitochondria was derived from P1, which was energy-dependently imported and concomitantly processed to the mature size [7].
• When the 35S-labeled cell-free translation products were incubated with rat liver mitochondria at 30 degrees C, P1 and the 35S-labeled mature size fumarase were associated with the mitochondria [7].
• Two different putative precursor polypeptides of rat liver fumarase were synthesized when RNA prepared from rat liver were translated in vitro using the rabbit reticulocyte lysate system [7].
• The cerebrum and cerebellum of myo-inositol deprived rats had normal myelination and mitochondriogenesis as judged by the levels of 2',3'-cyclic nucleotide-3'-phosphohydrolase (EC 3.1.4.1) and fumarase (EC 4.2.1.2) activity, respectively [8].
• Rat liver cells may contain a specific RNA(18S) modulating the translational activity of mRNA for fumarase [9].

Associations of Fh1 with chemical compounds

• The iron deficiency had little or no effect on the levels of a range of mitochondrial matrix enzymes, including citrate synthase, isocitrate dehydrogenase, fumarase, aspartate aminotransferase, 3-hydroxyacyl-CoA dehydrogenase, 3-ketoacid-CoA transferase, and acetoacetyl-CoA thiolase [10].
• In addition, citrate also competitively inhibits fumarase [11].
• After swelling in an isotonic solution of permeant ions, N-butylmaleimide-treated mitochondrial lost one-half of their malate dehydrogenase content, whereas fumarase and glutamate dehydrogenase did not leave the matrix space [12].
• This reveals that symmetric Krebs cycle intermediates undergo oriented transfer in the sequence of reactions catalysed by succinate thiokinase, succinate dehydrogenate and fumarase in the mitochondria of islet cells [13].
• The enzymes whose developmental patterns were studied were: pyruvate dehydrogenase (EC 1.2.4.1), 3-hydroxybutyrate dehydrogenase (EC 1.1.1.30), citrate synthase (EC 4.1.3.7), NAD-linked isocitrate dehydrogenase (EC 1.1.1.41) and fumarase (EC 4.2.1.2) [14].

Other interactions of Fh1

• The free radical scavengers (i.e. cuprozinc cytosolic and mangano mitochondrial superoxide dismutases, glutathione peroxidase, and catalase), mitochondrial oxidative marker enzymes (cytochrome c oxidase and fumarase), and lipid peroxide were measured in liver, heart, soleus (slow oxidative), and extensor digitorum longus (fast glycolytic) muscles [15].
• Activity levels for all five enzymes (CuZn-SOD, Mn-SOD, glutathione peroxidase, fumarase, and cytochrome c oxidase) were low for days 1-4 after release and did not return to control levels by the seventh day [16].
• The final preparation was free of malic dehydrogenase, fumarase, the strictly NADP+-linked malic enzyme and adenylate kinase [17].
• The levels of hexokinase, as well as those of the cytoplasmic glycolytic enzyme lactate dehydrogenase and the mitochondrial tricarboxylic acid cycle enzymes fumarase and citrate synthase, have been determined in whole rat brain and in neuronal, astrocytic, and oligodendroglial fractions isolated from rat brain [18].
• The effect of the lesion separated the enzymes into two groups: the activities of pyruvate dehydrogenase complex, carnitine acetyltransferase, fumarase and aspartate transaminase decreased by 30--40%, whereas the activities of the other enzymes descreased 5--15% [19].

Analytical, diagnostic and therapeutic context of Fh1

• 8. The oestrone from (3RS,6R)-[6-2H1,6-3H1,6-14C]mevalonate gave acetic acid which was converted into 2S-malate that retained 68.6% of its tritium after treatment with fumarate hydratase; the configuration of this acetic acid was R [20].
• Of the respiratory enzymes studied, sussinic dehydrogenase, fumarase and cytochrome oxidase, the activity of only the latter was markedly reduced by a chronic sympathetic denervation [21].
• The effect of adrenalectomy on the activities of monoamine oxidase (MAO), NADH cytochrome c reductase (NCR), succinate dehydrogenase, malate dehydrogenase, fumarase, NAD+ nucleosidase and acid phosphatase in homogenates of rat hearts was examined [22].
• Several glycolytic enzymes, and fumarase and aspartate aminotransferase were increased by orchidectomy in epididymal fat [23].
• When the in vitro translation products programmed by the poly A+ RNA fraction obtained from rat brain were purified by immunoprecipitation with anti-fumarase antibody and analyzed by SDS polyacrylamide gel electrophoresis and fluorography, only one polypeptide of 50 KD was detected as a precursor of fumarase [24].

References