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Boteva E, Mironova R. Maillard reaction and aging: can bacteria shed light on the link? BIOTECHNOL BIOTEC EQ 2019. [DOI: 10.1080/13102818.2019.1590160] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Affiliation(s)
- Elitsa Boteva
- Department of Gene Regulation, Institute of Molecular Biology ‘Roumen Tsanev’, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Roumyana Mironova
- Department of Gene Regulation, Institute of Molecular Biology ‘Roumen Tsanev’, Bulgarian Academy of Sciences, Sofia, Bulgaria
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2
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Evolution of Fish Let-7 MicroRNAs and Their Expression Correlated to Growth Development in Blunt Snout Bream. Int J Mol Sci 2017; 18:ijms18030646. [PMID: 28300776 PMCID: PMC5372658 DOI: 10.3390/ijms18030646] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Revised: 03/12/2017] [Accepted: 03/13/2017] [Indexed: 12/12/2022] Open
Abstract
The lethal-7 (let-7) miRNA, known as one of the first founding miRNAs, is present in multiple copies in a genome and has diverse functions in animals. In this study, comparative genomic analysis of let-7 miRNAs members in fish species indicated that let-7 miRNA is a sequence conserved family in fish, while different species have the variable gene copy numbers. Among the ten members including let-7a/b/c/d/e/f/g/h/i/j, the let-7a precursor sequence was more similar to ancestral sequences, whereas other let-7 miRNA members were separate from the late differentiation of let-7a. The mostly predicted target genes of let-7 miRNAs are involved in biological process, especially developmental process and growth through Gene Ontology (GO) enrichment analysis. In order to identify the possible different functions of these ten miRNAs in fish growth development, their expression levels were quantified in adult males and females of Megalobrama amblycephala, as well as in 3-, 6-, and 12-months-old individuals with relatively slow- and fast-growth rates. These ten miRNAs had similar tissue expression patterns between males and females, with higher expression levels in the brain and pituitary than that in other tissues (p < 0.05). Among these miRNAs, the relative expression level of let-7a was the highest among almost all the tested tissues, followed by let-7b, let-7d and let-7c/e/f/g/h/i/j. As to the groups with different growth rates, the expression levels of let-7 miRNAs in pituitary and brain from the slow-growth group were always significantly higher than that in the fast-growth group (p < 0.05). These results suggest that let-7 miRNA members could play an important role in the regulation of growth development in M. amblycephala through negatively regulating expression of their target genes.
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Tine M. Evolutionary significance and diversification of the phosphoglucose isomerase genes in vertebrates. BMC Res Notes 2015; 8:799. [PMID: 26682538 PMCID: PMC4684624 DOI: 10.1186/s13104-015-1683-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 11/09/2015] [Indexed: 01/20/2024] Open
Abstract
Background Phosphoglucose isomerase (PGI) genes are important multifunctional proteins whose evolution has, until now, not been well elucidated because of the limited number of completely sequenced genomes. Although the multifunctionality of this gene family has been considered as an original and innate characteristic, PGI genes may have acquired novel functions through changes in coding sequences and exon/intron structure, which are known to lead to functional divergence after gene duplication. A whole-genome comparative approach was used to estimate the rates of molecular evolution of this protein family. Results The results confirm the presence of two isoforms in teleost fishes and only one variant in all other vertebrates. Phylogenetic reconstructions grouped the PGI genes into five main groups: lungfishes/coelacanth/cartilaginous fishes, teleost fishes, amphibians, reptiles/birds and mammals, with the teleost group being subdivided into two subclades comprising PGI1 and PGI2. This PGI partitioning into groups is consistent with the synteny and molecular evolution results based on the estimation of the ratios of nonsynonymous to synonymous changes (Ka/Ks) and divergence rates between both PGI paralogs and orthologs. Teleost PGI2 shares more similarity with the variant found in all other vertebrates, suggesting that it has less evolved than PGI1 relative to the PGI of common vertebrate ancestor. Conclusions The diversification of PGI genes into PGI1 and PGI2 is consistent with a teleost-specific duplication before the radiation of this lineage, and after its split from the other infraclasses of ray-finned fishes. The low average Ka/Ks ratios within teleost and mammalian lineages suggest that both PGI1 and PGI2 are functionally constrained by purifying selection and may, therefore, have the same functions. By contrast, the high average Ka/Ks ratios and divergence rates within reptiles and birds indicate that PGI may be involved in different functions. The synteny analyses show that the genomic region harbouring PGI genes has independently undergone genomic rearrangements in mammals versus the reptile/bird lineage in particular, which may have contributed to the actual functional diversification of this gene family. Electronic supplementary material The online version of this article (doi:10.1186/s13104-015-1683-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mbaye Tine
- Molecular Zoology Laboratory, Department of Zoology, University of Johannesburg, Auckland Park, 2006, South Africa. .,Genome Centre Cologne at MPI for Plant Breeding Research, 22 Carl-von-Linné-Weg 10, 50829, Cologne, Germany.
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Kuravsky ML, Aleshin VV, Frishman D, Muronetz VI. Testis-specific glyceraldehyde-3-phosphate dehydrogenase: origin and evolution. BMC Evol Biol 2011; 11:160. [PMID: 21663662 PMCID: PMC3224139 DOI: 10.1186/1471-2148-11-160] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Accepted: 06/10/2011] [Indexed: 11/25/2022] Open
Abstract
Background Glyceraldehyde-3-phosphate dehydrogenase (GAPD) catalyses one of the glycolytic reactions and is also involved in a number of non-glycolytic processes, such as endocytosis, DNA excision repair, and induction of apoptosis. Mammals are known to possess two homologous GAPD isoenzymes: GAPD-1, a well-studied protein found in all somatic cells, and GAPD-2, which is expressed solely in testis. GAPD-2 supplies energy required for the movement of spermatozoa and is tightly bound to the sperm tail cytoskeleton by the additional N-terminal proline-rich domain absent in GAPD-1. In this study we investigate the evolutionary history of GAPD and gain some insights into specialization of GAPD-2 as a testis-specific protein. Results A dataset of GAPD sequences was assembled from public databases and used for phylogeny reconstruction by means of the Bayesian method. Since resolution in some clades of the obtained tree was too low, syntenic analysis was carried out to define the evolutionary history of GAPD more precisely. The performed selection tests showed that selective pressure varies across lineages and isoenzymes, as well as across different regions of the same sequences. Conclusions The obtained results suggest that GAPD-1 and GAPD-2 emerged after duplication during the early evolution of chordates. GAPD-2 was subsequently lost by most lineages except lizards, mammals, as well as cartilaginous and bony fishes. In reptilians and mammals, GAPD-2 specialized to a testis-specific protein and acquired the novel N-terminal proline-rich domain anchoring the protein in the sperm tail cytoskeleton. This domain is likely to have originated by exonization of a microsatellite genomic region. Recognition of the proline-rich domain by cytoskeletal proteins seems to be unspecific. Besides testis, GAPD-2 of lizards was also found in some regenerating tissues, but it lacks the proline-rich domain due to tissue-specific alternative splicing.
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Affiliation(s)
- Mikhail L Kuravsky
- Faculty of Bioengineering and Bioinformatics, MV Lomonosov Moscow State University, Moscow, Russian Federation
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Jeyasingh PD, Weider LJ, Sterner RW. Genetically-based trade-offs in response to stoichiometric food quality influence competition in a keystone aquatic herbivore. Ecol Lett 2009; 12:1229-37. [PMID: 19719840 DOI: 10.1111/j.1461-0248.2009.01368.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Lin WW, Chen LH, Chen MC, Kao HW. Differential expression of zebrafish gpia and gpib during development. Gene Expr Patterns 2009; 9:238-45. [DOI: 10.1016/j.gep.2008.12.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2008] [Revised: 12/20/2008] [Accepted: 12/22/2008] [Indexed: 10/21/2022]
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Gaowa S, Zhang S. Identification, expression, function and localization of a DUF985 domain-containing hypothetical gene from amphioxus Branchiostoma belcheri. Comp Biochem Physiol B Biochem Mol Biol 2009; 152:28-37. [DOI: 10.1016/j.cbpb.2008.09.085] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2008] [Revised: 09/07/2008] [Accepted: 09/08/2008] [Indexed: 11/28/2022]
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Sato Y, Nishida M. Electric charge divergence in proteins: insights into the evolution of their three-dimensional properties. Gene 2008; 441:3-11. [PMID: 18652881 DOI: 10.1016/j.gene.2008.06.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2008] [Revised: 06/13/2008] [Accepted: 06/17/2008] [Indexed: 11/28/2022]
Abstract
Previous studies of protein evolution have identified important mutations in various proteins that affect a small number of residues, but dramatically alter protein function. However, the evolutionary process underlying the three-dimensional protein properties, which are determined by a much larger number of residues, remains unclear. Based on a comparative evolutionary analysis of teleost phosphoglucose isomerases (PGIs; EC 5.3.1.9), we previously demonstrated that the relatively weak selection on many amino acid sites has played an important role in the evolution of protein electric charge as a model of three-dimensional protein properties. To ascertain the generality of this finding, we sought further evidence of this type of protein evolution. For this purpose, we analyzed the vertebrate isoforms of fructose-1,6-bisphosphate aldolase (ALD; EC 4.1.2.13), for which electric charges are known to have diverged after gene duplication. The results showed that the divergence in electric charge between the ALD isoforms was also driven by weak selection on many amino acid sites, as in PGI, confirming the generality of earlier findings. To obtain further insights, ALD and PGI were compared to the proteins pancreatic ribonuclease (EC 3.1.27.5) and triose-phosphate isomerase (EC 5.3.1.1), for which electric charges likely evolved through a well-defined mode of molecular evolution; namely, strong selection on specific amino acid sites. Comparison of the number and composition of amino acids on the protein surface suggested that the absolute number of evolutionarily changeable amino acids in a protein affects the strength of selection pressure acting on individual amino acid sites.
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Affiliation(s)
- Yukuto Sato
- Division of Molecular Marine Biology, Ocean Research Institute, University of Tokyo, Minamidai 1-15-1, Nakano-ku, Tokyo 164-8639, Japan.
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Sato Y, Nishida M. Post-duplication charge evolution of phosphoglucose isomerases in teleost fishes through weak selection on many amino acid sites. BMC Evol Biol 2007; 7:204. [PMID: 17963532 PMCID: PMC2176064 DOI: 10.1186/1471-2148-7-204] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2007] [Accepted: 10/29/2007] [Indexed: 11/21/2022] Open
Abstract
Background The partitioning of ancestral functions among duplicated genes by neutral evolution, or subfunctionalization, has been considered the primary process for the evolution of novel proteins (neofunctionalization). Nonetheless, how a subfunctionalized protein can evolve into a more adaptive protein is poorly understood, mainly due to the limitations of current analytical methods, which can detect only strong selection for amino acid substitutions involved in adaptive molecular evolution. In this study, we employed a comparative evolutionary approach to this question, focusing on differences in the structural properties of a protein, specifically the electric charge, encoded by fish-specific duplicated phosphoglucose isomerase (Pgi) genes. Results Full-length cDNA cloning, RT-PCR based gene expression analyses, and comparative sequence analyses showed that after subfunctionalization with respect to the expression organ of duplicate Pgi genes, the net electric charge of the PGI-1 protein expressed mainly in internal tissues became more negative, and that of PGI-2 expressed mainly in muscular tissues became more positive. The difference in net protein charge was attributable not to specific amino acid sites but to the sum of various amino acid sites located on the surface of the PGI molecule. Conclusion This finding suggests that the surface charge evolution of PGI proteins was not driven by strong selection on individual amino acid sites leading to permanent fixation of a particular residue, but rather was driven by weak selection on a large number of amino acid sites and consequently by steady directional and/or purifying selection on the overall structural properties of the protein, which is derived from many modifiable sites. The mode of molecular evolution presented here may be relevant to various cases of adaptive modification in proteins, such as hydrophobic properties, molecular size, and electric charge.
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Affiliation(s)
- Yukuto Sato
- Division of Molecular Marine Biology, Ocean Research Institute, The University of Tokyo, 1-15-1 Minamidai, Nakano-ku, Tokyo 164-8639, Japan.
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Mathur D, Anand K, Mathur D, Jagadish N, Suri A, Garg LC. Crystallization and preliminary X-ray characterization of phosphoglucose isomerase from Mycobacterium tuberculosis H37Rv. Acta Crystallogr Sect F Struct Biol Cryst Commun 2007; 63:353-5. [PMID: 17401215 PMCID: PMC2330222 DOI: 10.1107/s1744309107013218] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2006] [Accepted: 03/20/2007] [Indexed: 11/10/2022]
Abstract
Phosphoglucose isomerase is a ubiquitous enzyme that catalyzes the isomerization of D-glucopyranose-6-phosphate to D-fructofuranose-6-phosphate. The present investigation reports the expression, purification, crystallization and preliminary crystallographic studies of the phosphoglucose isomerase from Mycobacterium tuberculosis H37Rv, which shares 46% sequence identity with that of its human host. The recombinant protein, which was prepared using an Escherichia coli expression system, was crystallized by the hanging-drop vapour-diffusion method. The crystals diffracted to a resolution of 2.8 A and belonged to the orthorhombic space group I2(1)2(1)2(1), with unit-cell parameters a = 109.0, b = 119.8, c = 138.9 A.
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Affiliation(s)
- Divya Mathur
- Gene Regulation Laboratory, National Institute of Immunology, New Delhi 110067, India
| | - Kanchan Anand
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Deepika Mathur
- Gene Regulation Laboratory, National Institute of Immunology, New Delhi 110067, India
| | - Nirmala Jagadish
- Genes and Proteins Laboratory, National Institute of Immunology, New Delhi 110067, India
| | - Anil Suri
- Genes and Proteins Laboratory, National Institute of Immunology, New Delhi 110067, India
| | - Lalit C. Garg
- Gene Regulation Laboratory, National Institute of Immunology, New Delhi 110067, India
- Correspondence e-mail: ,
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Steinke D, Hoegg S, Brinkmann H, Meyer A. Three rounds (1R/2R/3R) of genome duplications and the evolution of the glycolytic pathway in vertebrates. BMC Biol 2006; 4:16. [PMID: 16756667 PMCID: PMC1508162 DOI: 10.1186/1741-7007-4-16] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2006] [Accepted: 06/06/2006] [Indexed: 11/30/2022] Open
Abstract
Background Evolution of the deuterostome lineage was accompanied by an increase in systematic complexity especially with regard to highly specialized tissues and organs. Based on the observation of an increased number of paralogous genes in vertebrates compared with invertebrates, two entire genome duplications (2R) were proposed during the early evolution of vertebrates. Most glycolytic enzymes occur as several copies in vertebrate genomes, which are specifically expressed in certain tissues. Therefore, the glycolytic pathway is particularly suitable for testing theories of the involvement of gene/genome duplications in enzyme evolution. Results We assembled datasets from genomic databases of at least nine vertebrate species and at least three outgroups (one deuterostome and two protostomes), and used maximum likelihood and Bayesian methods to construct phylogenies of the 10 enzymes of the glycolytic pathway. Through this approach, we intended to gain insights into the vertebrate specific evolution of enzymes of the glycolytic pathway. Many of the obtained gene trees generally reflect the history of two rounds of duplication during vertebrate evolution, and were in agreement with the hypothesis of an additional duplication event within the lineage of teleost fish. The retention of paralogs differed greatly between genes, and no direct link to the multimeric structure of the active enzyme was found. Conclusion The glycolytic pathway has subsequently evolved by gene duplication and divergence of each constituent enzyme with taxon-specific individual gene losses or lineage-specific duplications. The tissue-specific expression might have led to an increased retention for some genes since paralogs can subdivide the ancestral expression domain or find new functions, which are not necessarily related to the original function.
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Affiliation(s)
- Dirk Steinke
- Lehrstuhl für Evolutionsbiologie und Zoologie, Department of Biology, University of Konstanz, 78457 Konstanz, Germany
- Canadian Centre for DNA Barcoding, Biodiversity Institute of Ontario, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Simone Hoegg
- Lehrstuhl für Evolutionsbiologie und Zoologie, Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Henner Brinkmann
- Département de biochimie. Université de Montreal, Montreal, QC, H3C3J7, Canada
| | - Axel Meyer
- Lehrstuhl für Evolutionsbiologie und Zoologie, Department of Biology, University of Konstanz, 78457 Konstanz, Germany
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Crow KD, Stadler PF, Lynch VJ, Amemiya C, Wagner GP. The "fish-specific" Hox cluster duplication is coincident with the origin of teleosts. Mol Biol Evol 2005; 23:121-36. [PMID: 16162861 DOI: 10.1093/molbev/msj020] [Citation(s) in RCA: 149] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The Hox gene complement of zebrafish, medaka, and fugu differs from that of other gnathostome vertebrates. These fishes have seven to eight Hox clusters compared to the four Hox clusters described in sarcopterygians and shark. The clusters in different teleost lineages are orthologous, implying that a "fish-specific" Hox cluster duplication has occurred in the stem lineage leading to the most recent common ancestor of zebrafish and fugu. The timing of this event, however, is unknown. To address this question, we sequenced four Hox genes from taxa representing basal actinopterygian and teleost lineages and compared them to known sequences from shark, coelacanth, zebrafish, and other teleosts. The resulting gene genealogies suggest that the fish-specific Hox cluster duplication occurred coincident with the origin of crown group teleosts. In addition, we obtained evidence for an independent Hox cluster duplication in the sturgeon lineage (Acipenseriformes). Finally, results from HoxA11 suggest that duplicated Hox genes have experienced diversifying selection immediately after the duplication event. Taken together, these results support the notion that the duplicated Hox genes of teleosts were causally relevant to adaptive evolution during the initial teleost radiation.
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Affiliation(s)
- Karen D Crow
- Department of Ecology and Evolutionary Biology, Yale University, USA.
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Hoegg S, Brinkmann H, Taylor JS, Meyer A. Phylogenetic timing of the fish-specific genome duplication correlates with the diversification of teleost fish. J Mol Evol 2005; 59:190-203. [PMID: 15486693 DOI: 10.1007/s00239-004-2613-z] [Citation(s) in RCA: 427] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2003] [Accepted: 02/13/2004] [Indexed: 10/26/2022]
Abstract
For many genes, ray-finned fish (Actinopterygii) have two paralogous copies, where only one ortholog is present in tetrapods. The discovery of an additional, almost-complete set of Hox clusters in teleosts (zebrafish, pufferfish, medaka, and cichlid) but not in basal actinopterygian lineages ( Polypterus) led to the formulation of the fish-specific genome duplication hypothesis. The phylogenetic timing of this genome duplication during the evolution of ray-finned fish is unknown, since only a few species of basal fish lineages have been investigated so far. In this study, three nuclear genes ( fzd8, sox11, tyrosinase) were sequenced from sturgeons (Acipenseriformes), gars (Semionotiformes), bony tongues (Osteoglossomorpha), and a tenpounder (Elopomorpha). For these three genes, two copies have been described previously teleosts (e.g., zebrafish, pufferfish), but only one orthologous copy is found in tetrapods. Individual gene trees for these three genes and a concatenated dataset support the hypothesis that the fish-specific genome duplication event took place after the split of the Acipenseriformes and the Semionotiformes from the lineage leading to teleost fish but before the divergence of Osteoglossiformes. If these three genes were duplicated during the proposed fish-specific genome duplication event, then this event separates the species-poor early-branching lineages from the species-rich teleost lineage. The additional number of genes resulting from this event might have facilitated the evolutionary radiation and the phenotypic diversification of the teleost fish.
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Affiliation(s)
- Simone Hoegg
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
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Yanagawa T, Funasaka T, Tsutsumi S, Raz T, Tanaka N, Raz A. Differential Regulation of Phosphoglucose Isomerase/Autocrine Motility Factor Activities by Protein Kinase CK2 Phosphorylation. J Biol Chem 2005; 280:10419-26. [PMID: 15637053 DOI: 10.1074/jbc.m409457200] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phosphoglucose isomerase (PGI; EC 5.3.1.9) is a cytosolic housekeeping enzyme of the sugar metabolism pathways that plays a key role in both glycolysis and gluconeogenesis. PGI is a multifunctional dimeric protein that extracellularly acts as a cytokine with properties that include autocrine motility factor (AMF)-eliciting mitogenic, motogenic, and differentiation functions, and PGI has been implicated in tumor progression and metastasis. Little is known of the biochemical regulation of PGI/AMF activities, although it is known that human PGI/AMF is phosphorylated at Ser(185) by protein kinase CK2 (CK2); however, the physiological significance of this phosphorylation is unknown. Thus, by site-directed mutagenesis, we substituted Ser(185) with aspartic acid (S185D) or glutamic acid (S185E), which introduces a negative charge and conformational changes that mimic phosphorylation. A Ser-to-Ala mutant protein (S185A) was generated to abolish phosphorylation. Biochemical analyses revealed that the phosphorylation mutant proteins of PGI exhibited decreased enzymatic activity, whereas the S185A mutant PGI protein retained full enzymatic activity. PGI phosphorylation by CK2 also led to down-regulation of enzymatic activity. Furthermore, CK2 knockdown by RNA interference was associated with up-regulation of cellular PGI enzymatic activity. The three recombinant mutant proteins exhibited indistinguishable cytokine activity and receptor-binding affinities compared with the wild-type protein. In both in vitro and in vivo assays, the wild-type and S185A mutant proteins underwent active species dimerization, whereas both the S185D and S185E mutant proteins also formed tetramers. These results demonstrate that phosphorylation affects the allosteric kinetic properties of the enzyme, resulting in a less active form of PGI, whereas non-phosphorylated protein species retain cytokine activity. The process by which phosphorylation modulates the enzymatic activity of PGI thus has an important implication for the understanding of the biological regulation of this key glucose metabolism-regulating enzyme.
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Affiliation(s)
- Takashi Yanagawa
- Tumor Progression and Metastasis Program, Karmanos Cancer Institute, 110 E. Warren Ave., Detroit, Michigan 48201, USA
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