Cell proliferation-associated expression of a recently evolved isozyme of triosephosphate isomerase

Decker, Robert S.; Mohrenweiser, Harvey W.

doi:10.1007/bf00504324

Cited by 12 publications

(25 citation statements)

References 36 publications

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“…When L153 extracts were incubated at 520C, the thermolabile TPI-1/2 and TPI-2/2 isozymes disappeared, while TPI-1/1 activity remained constant ( Fig. 2A) (27,31,32). In contrast to L153 extracts, untreated extracts of the TPI-deficient fibroblasts contained detectable amounts of only the TPI-1/1 isozyme, and all enzymatic activity was lost after incubation at 52°C (Fig.…”

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confidence: 95%

“…TPI-1 and TPI-2 subunits are products of the same DNA locus, as demonstrated by studies of naturally occurring variant isozyme patterns (34) and TPI cDNA and genomic sequences (3,16). TPI-1 is constitutively expressed, whereas TPI-2 expression is restricted to dividing cells and is the more unstable of the two forms (32,33). When L153 extracts were incubated at 520C, the thermolabile TPI-1/2 and TPI-2/2 isozymes disappeared, while TPI-1/1 activity remained constant ( Fig.…”

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confidence: 98%

“…We chose an electrophoretic approach in measuring TPI activity to resolve the several isozymes known to be present in cultured human fibroblasts (27,(31)(32)(33). Upon staining the gel for TPI activity, TPI-1/1 and TPI-1/2 (32), also referred to as isozymes a and e, respectively, (27) were readily detected in L153 extracts ( Fig.…”

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confidence: 99%

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Human triose-phosphate isomerase deficiency: a single amino acid substitution results in a thermolabile enzyme.

Daar¹,

Artymiuk²,

Phillips³

et al. 1986

Proc. Natl. Acad. Sci. U.S.A.

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Triose-phosphate isomerase (TPI; D-glyceraldehyde-3-phosphate ketol-isomerase, EC 5.3.1.1) deficiency is a recessive disorder that results in hemolytic anemia and neuromuscular dysfunction. To determine the molecular basis of this disorder, a TPI allele from two unrelated patients homozygous for TPI deficiency was compared with an allele from a normal individual. Each disease-associated sequence harbors a G-C -+ C-G transversion in the codon for amino acid-104 and specifies a structurally altered protein in which a glutamate residue is replaced by an aspartate residue. The importance of glutamate-104 to enzyme structure and function is implicated by its conservation in the TPI protein of all species that have been characterized to date. The glutamate-toaspartate substitution results in a thermolabile enzyme as demonstrated by assaysof-TPI activity in cultured fibroblasts of each patient and cultured Chinese hamster ovary (CHO) cells that were stably transformed with the mutant alleles. Although this substitution conserves the overall charge of amino acid-104, the x-ray crystal structure of chicken TPI indicates that the loss of a side-chain methylene group (-CH2CH2COO -* -CH2COO ) is sufficient to disrupt the counterbalancing of charges that normally exists within a hydrophobic pocket of the native enzyme.Triose-phosphate isomerase (TPI; D-glyceraldehyde-3-phosphate ketol-isomerase, EC 5.3.1.1) catalyzes the movement of a single proton to interconvert dihydroxyacetone phosphate and glyceraldehyde 3-phosphate in glycolysis and gluconeogenesis (1). The enzyme, a dimer of identical subunits that are 248 amino acids in humans (2, 3), has no cofactors, required metal ions, or cooperativity between subunits. Both prokaryotic and eukaryotic TPI are very similar in sequence and structure and are characterized by a high catalytic efficiency. The second-order rate constant for the formation of dihydroxyacetone phosphate, the thermodynamically favored reaction, is close to the rate constant for a diffusion-limited encounter of substrate and enzyme (4, 5).Site-directed mutagenesis combined with crystallographic and kinetic studies have provided a means of defining the contribution of specific TPI amino acids to enzyme activity (6, 7). This method has focused on amino acids implicated by high-resolution structural data and chemical-modification experiments to be important to the catalytic mechanism of the enzyme. We have chosen a complementary approach to understand TPI structure-function relationships in studying natural TPI gene mutations that exist within the human population. Hereditary TPI deficiency is an autosomal recessive disease that has severe clinical manifestations including chronic hemolytic anemia and neuromuscular disorders (8). Homozygous-deficient individuals usually have 3-20% of normal TPI activity; all of this activity is heat labile, suggesting that at least one allele encodes a structurally altered protein (3, 9, 10). The other allele is presumably null, since mutations producing no detectable ...

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Human triose-phosphate isomerase deficiency: a single amino acid substitution results in a thermolabile enzyme.

Daar¹,

Artymiuk²,

Phillips³

et al. 1986

Proc. Natl. Acad. Sci. U.S.A.

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“…The appearance of the induced isozymes in mitogen stimulated, human peripheral lymphocytes requires RNA synthesis and de novo protein synthesis (17). Isozymes analogous to the mitogen induced isozyme are observed in other actively proliferating human cells of both normal and transformed phenotypes (12)(13)(14)16). The expression of the mitogen induced, proliferation specific isozyme is a unique feature of cells from hominoid species (18); that is, the unique induced isozymes are not detected in dividing cells from lower primates or rabbits (14,18).…”

Section: Introductionmentioning

confidence: 99%

“…Recent data suggest that, in addition to expression of many oncogenes (7,8) and cellular growth factors (9,10) an increased ex-pression of several glycolytic enzymes, including triosephosphate isomerase (TPI: EC 5.3.1.1) is a relatively early response to mitogenic or growth factor stimulation of quiescent cells (11). TPI activity is increased 2-3 fold following mitogen stimulation of peripheral lymphocytes (12,13) and is also increased in proliferating established cells, relative to quiescent cells (13,14).…”

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confidence: 99%

Hominoid triosephosphate isomerase: Characterization of the major cell proliferation specific isozyme

Decker

Mohrenweiser

1986

Mol Cell Biochem

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Proliferating cells derived from hominoid species contain electrophoretically separable forms of triosephosphate isomerase (TPI), including a constitutive isozyme and major and minor cell proliferation specific isozymes. Genetic studies have shown that the constitutive and inducible isozymes are products of the same structural gene. A procedure has been developed for the rapid isolation of the constitutive and major proliferation specific TPI isozymes from human lymphoblastoid B cells. [35S]methionine labeled isozymes were purified through several steps of polyacrylamide gel electrophoresis in sufficient quantities for turnover studies and preliminary structural analysis. The intact isozymes were subjected to 23 steps of automated Edman degradation; both preparations yield a [35S] PTH-methionine only at cycle 14, as expected if the protein is TPI. Neither isozyme contains a blocked NH2-terminus and length heterogeneity at the amino terminal does not exist. A comparison of the two purified isozymes on 2-D PAGE confirms that the constitutive isozyme consists of only type 1 subunits while the major proliferation specific isozyme is composed of a type 1 subunit and a unique type 2 subunit. The type 1 and type 2 subunits differ by at least four charge units under native, nondenaturing conditions of electrophoresis but do not differ in molecular mass. The difference between the type 1 and type 2 subunits is covalent, as the difference in isoelectric point between the two subunits is stable to both 2% SDS and 8 M urea. The expression of TPI-2 does not correlate with the existence of the labile asparagine residues. Turnover studies indicate that the level of each subunit is regulated by differences in rates of synthesis rather than degradation but a precursor-product relationship between the subunits was not observed. Thus the mechanism for synthesis of TPI-2 must operate either during mRNA processing or nascent peptide synthesis and then only in cells from hominoid species.

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Evidence for Post‐translational Modification of Triose Phosphate Isomerase (Tpi) in Isoëtes (Isoëtaceae)

Hickey

Guttman

Eshbaugh

1989

American J of Botany

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As part of an electrophoretic study on Isoëtes, a number of Neotropical and North American species were examined for allozyme variation in TPI. Three of these species—I. storkii, I. flaccida, and I. mexicana—exhibit three distinct zones of TPI activity. The two most anodally migrating zones are comparable to the two zones found in most angiosperms and in several other species of Isoëtes. The single or three‐banded phenotypes produced at these loci correspond, respectively, to the homozygous and heterozygous patterns typical of a dimeric enzyme. The most cathodal zone (zone III) differs in producing either single or two‐banded phenotypes. Analyses of these three zones indicate a nearly perfect correlation between zones II and III in putative allelic constitution and relative allelic mobility. Explanations involving TPI gene duplications and/or null alleles fail to account for the peculiar banding characteristics and origin of activity zone III. An alternative hypothesis involving a protease duplication and differential post‐translational modification is postulated. This hypothesis adequately explains the zone III phenotypes and fixation of the third activity zone in the species examined. Amino acid sequencing is suggested as the most direct test of this hypothesis. The taxonomic distribution of TPI III generally supports a previous, morphologically‐based, hypothesis on species relationships in Isoëtes. The presence of this zone is regarded as an independent synapomorphy for a major clade of Neotropical Isoëtes.

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Cell proliferation-associated expression of a recently evolved isozyme of triosephosphate isomerase

Cited by 12 publications

References 36 publications

Human triose-phosphate isomerase deficiency: a single amino acid substitution results in a thermolabile enzyme.

Human triose-phosphate isomerase deficiency: a single amino acid substitution results in a thermolabile enzyme.

Hominoid triosephosphate isomerase: Characterization of the major cell proliferation specific isozyme

Evidence for Post‐translational Modification of Triose Phosphate Isomerase (Tpi) in Isoëtes (Isoëtaceae)

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