Age-Related Changes of GIyceraldehyde-3-Phosphate Dehydrogenase (E.C. 1.2.1.12), 3-Phosphoglyceratekinase (E.C. 2.7.2.3), Phosphoglyceratemutase (E.C. 2.7.5.3), and Enolase (E.C. 4.2.1.11) in Bovine Lenses

Ohrloff, C.; Berdjis, H.; Hockwin, O.; Bours, J.

doi:10.1159/000265275

Cited by 7 publications

(4 citation statements)

References 11 publications

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“…Protein changes in the αB-R120G lenses were distinctly different from those in αA-R49C mutant lenses. The main changes in the αB-R120G mutant lens included altered abundance of β- and γ-crystallins, increased degradation of αA-, αB-, and γ-crystallins, and degradation of phosphoglycerate mutase, a glycolytic enzyme that is very important in metabolism but has not been studied in the lens in detail [46]–[49]. There was also a 12-fold increase in the amount of αA-crystallin associated with grifin in these lenses.…”

Section: Discussionmentioning

confidence: 99%

In Vivo Substrates of the Lens Molecular Chaperones αA-Crystallin and αB-Crystallin

2014

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αA-crystallin and αB-crystallin are members of the small heat shock protein family and function as molecular chaperones and major lens structural proteins. Although numerous studies have examined their chaperone-like activities in vitro, little is known about the proteins they protect in vivo. To elucidate the relationships between chaperone function, substrate binding, and human cataract formation, we used proteomic and mass spectrometric methods to analyze the effect of mutations associated with hereditary human cataract formation on protein abundance in αA-R49C and αB-R120G knock-in mutant lenses. Compared with age-matched wild type lenses, 2-day-old αA-R49C heterozygous lenses demonstrated the following: increased crosslinking (15-fold) and degradation (2.6-fold) of αA-crystallin; increased association between αA-crystallin and filensin, actin, or creatine kinase B; increased acidification of βB1-crystallin; increased levels of grifin; and an association between βA3/A1-crystallin and αA-crystallin. Homozygous αA-R49C mutant lenses exhibited increased associations between αA-crystallin and βB3-, βA4-, βA2-crystallins, and grifin, whereas levels of βB1-crystallin, gelsolin, and calpain 3 decreased. The amount of degraded glutamate dehydrogenase, α-enolase, and cytochrome c increased more than 50-fold in homozygous αA-R49C mutant lenses. In αB-R120G mouse lenses, our analyses identified decreased abundance of phosphoglycerate mutase, several β- and γ-crystallins, and degradation of αA- and αB-crystallin early in cataract development. Changes in the abundance of hemoglobin and histones with the loss of normal α-crystallin chaperone function suggest that these proteins also play important roles in the biochemical mechanisms of hereditary cataracts. Together, these studies offer a novel insight into the putative in vivo substrates of αA- and αB-crystallin.

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Section: Discussionmentioning

confidence: 99%

In Vivo Substrates of the Lens Molecular Chaperones αA-Crystallin and αB-Crystallin

2014

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“…31, 32), while enolase is only active as a dimer (30). Other studies of enolase activity in mammalian (14) and chicken (19) lenses have also shown a reduction in size and activity of enolase in the older fiber cells as compared with the newly synthesized protein in epithelial cells. This suggests that enolase, and therefore x-crystallin, is subject to posttranslational modification with aging, undergoing monomerization and loss of activity.…”

Section: Discussionmentioning

confidence: 93%

Tau-crystallin/alpha-enolase: one gene encodes both an enzyme and a lens structural protein.

Wistow

Lietman

Williams

et al. 1988

The Journal of Cell Biology

148

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tau-Crystallin has been a major component of the cellular lenses of species throughout vertebrate evolution, from lamprey to birds. Immunofluorescence analysis of the embryonic turtle lens, using antiserum to lamprey tau-crystallin showed that the protein is expressed throughout embryogenesis and is present at high concentrations in all parts of the lens. Partial peptide sequence for the isolated turtle protein and deduced sequences for several lamprey peptides all revealed a close similarity to the glycolytic enzyme enolase (E.C. 4.2.1.11). A full-sized cDNA for putative duck tau-crystallin was obtained and sequenced, confirming the close relationship with alpha-enolase. Southern blot analysis showed that the duck genome contains a single alpha-enolase gene, while Northern blot analysis showed that the message for tau-crystallin/alpha-enolase is present in embryonic duck lens at 25 times the abundance found in liver. tau-Crystallin possesses enolase activity, but the activity is greatly reduced, probably because of age-related posttranslational modification. It thus appears that a highly conserved, important glycolytic enzyme has been used as a structural component of lens since the start of vertebrate evolution. Apparently the enzyme has not been recruited for its catalytic activity but for some distinct structural property. tau-Crystallin/alpha-enolase is an example of a multifunctional protein playing two very different roles in evolution but encoded by a single gene.

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“…It was up-regulated in SAMP8 and also reported to be overexpressed in human dermal fibroblasts with aging [38] . Phosphoglycerate mutase I sustained changes in its molecular weight and substrate affinity in the old tissues, causing the decline of specific activities with aging [56] . This may suggest that aged SAMP8 mice might need higher levels of phosphoglycerate mutase I to maintain the normal carbohydrate metabolism.…”

Section: Functional Discussion Dealing With Aging and Aging-related mentioning

confidence: 99%

Comparative Proteome Analysis of Splenic Lymphocytes in Senescence-Accelerated Mice

Luo¹,

Lin

et al. 2009

Gerontology

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Background: Senescence-accelerated mice (SAM) are commonly used as animal models for studying aging. To date, aging-related proteomes in the livers and brains of SAMP8 mice have been reported; however, spleen of SAM has not yet been used as material for studying the aging-related proteome despite its extremely important role in the progress of aging or aging-related diseases. Objective: To identify proteins associated with aging or aging-related diseases in SAM. Methods: Two-dimensional gel electrophoresis (2DE) was used to compare the proteomes of splenic lymphocytes from two strains of SAM (SAMP8 and SAMR1). Differentially expressed spots whose expression altered over twofold (p < 0.01) were identified by LC-MS/MS and database search. Results: Identification results showed that 18 differentially expressed protein spots represented 14 different proteins known to be involved in aging- or aging disease-related pathways, i.e., annexin I, calgranulin B, transaldolase, isocitrate dehydrogenase, and an unnamed protein product were involved in oxidative stress and cell defense, phosphoglycerate mutase I, aldose reductase, carbonic anhydrase I and carbonic anhydrase II were involved in glycolytic energy metabolism and homeostasis, and macrophage capping protein and high mobility group box-1 protein were involved in infection and DNA damage. Conclusion: 2DE combined with MS is effective for comparative proteome analysis of splenic lymphocytes of SAM to identify proteins closely involved in aging or aging-related diseases, especially immune diseases, and further functional studies of these proteins in SAM may throw some light on the study of biomarkers for aging or aging-related diseases.

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Age-Related Changes of GIyceraldehyde-3-Phosphate Dehydrogenase (E.C. 1.2.1.12), 3-Phosphoglyceratekinase (E.C. 2.7.2.3), Phosphoglyceratemutase (E.C. 2.7.5.3), and Enolase (E.C. 4.2.1.11) in Bovine Lenses

Abstract: The specific activities of the four investigated enzymes of the carbohydrate metabolism decrease with ageing. In the old tissue, phosphoglyceratemutase and enolase sustain changes in their molecular weight, and their substrate affinity is modified.

Cited by 7 publications

References 11 publications

In Vivo Substrates of the Lens Molecular Chaperones αA-Crystallin and αB-Crystallin

In Vivo Substrates of the Lens Molecular Chaperones αA-Crystallin and αB-Crystallin

Tau-crystallin/alpha-enolase: one gene encodes both an enzyme and a lens structural protein.

Comparative Proteome Analysis of Splenic Lymphocytes in Senescence-Accelerated Mice

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