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Pappas CJ, Xu H, Motaleb MA. Creating a Library of Random Transposon Mutants in Leptospira. Methods Mol Biol 2020; 2134:77-96. [PMID: 32632861 PMCID: PMC7473121 DOI: 10.1007/978-1-0716-0459-5_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Generation of a random transposon mutant library is advantageous in Leptospira as site-directed mutagenesis remains a challenge, especially in pathogenic species. This procedure is typically completed by transformation of Leptospira with a Himar1 containing plasmid via conjugation with Escherichia coli as a donor cell. Here we describe the methodology to generate random transposon mutants in the saprophyte Leptospira biflexa via conjugation of plasmid pSW29T-TKS2 harbored in E. coli β2163. Determination of transposon insertion site by semi-random nested PCR will also be described. A similar methodology may be employed to generate Tn mutants of pathogenic Leptospira species.
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Affiliation(s)
| | - Hui Xu
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | - Md A Motaleb
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, NC, USA
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Abstract
This chapter covers the progress made in the Leptospira field since the application of mutagenesis techniques and how they have allowed the study of virulence factors and, more generally, the biology of Leptospira. The last decade has seen advances in our ability to perform molecular genetic analysis of Leptospira. Major achievements include the generation of large collections of mutant strains and the construction of replicative plasmids, enabling complementation of mutations. However, there are still no practical tools for routine genetic manipulation of pathogenic Leptospira strains, slowing down advances in pathogenesis research. This review summarizes the status of the molecular genetic toolbox for Leptospira species and highlights new challenges in the nascent field of Leptospira genetics.
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Affiliation(s)
- Mathieu Picardeau
- Biology of Spirochetes Unit, Institut Pasteur, 28 Rue Du Docteur Roux, 75724, Paris Cedex 15, France.
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Ghazaei C. Pathogenic Leptospira: Advances in understanding the molecular pathogenesis and virulence. Open Vet J 2018; 8:13-24. [PMID: 29445617 PMCID: PMC5806663 DOI: 10.4314/ovj.v8i1.4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2017] [Accepted: 01/08/2018] [Indexed: 12/16/2022] Open
Abstract
Leptospirosis is a common zoonotic disease has emerged as a major public health problem, with developing countries bearing disproportionate burdens. Although the diverse range of clinical manifestations of the leptospirosis in humans is widely documented, the mechanisms through which the pathogen causes disease remain undetermined. In addition, leptospirosis is a much-neglected life-threatening disease although it is one of the most important zoonoses occurring in a diverse range of epidemiological distribution. Recent advances in molecular profiling of pathogenic species of the genus Leptospira have improved our understanding of the evolutionary factors that determine virulence and mechanisms that the bacteria employ to survive. However, a major impediment to the formulation of intervention strategies has been the limited understanding of the disease determinants. Consequently, the association of the biological mechanisms to the pathogenesis of Leptospira, as well as the functions of numerous essential virulence factors still remain implicit. This review examines recent advances in genetic screening technologies, the underlying microbiological processes, the virulence factors and associated molecular mechanisms driving pathogenesis of Leptospira species.
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Affiliation(s)
- Ciamak Ghazaei
- Department of Microbiology, University of Mohaghegh Ardabili, P.O. Box 179, Ardabil, Iran
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Abstract
Recent advances in molecular genetics, such as the ability to construct defined mutants, have allowed the study of virulence factors and more generally the biology in Leptospira. However, pathogenic leptospires remain much less easily transformable than the saprophyte L. biflexa and further development and improvement of genetic tools are required. Here, we review tools that have been used to genetically manipulate Leptospira. We also describe the major advances achieved in both genomics and postgenomics technologies, including transcriptomics and proteomics.
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Ko AI, Goarant C, Picardeau M. Leptospira: the dawn of the molecular genetics era for an emerging zoonotic pathogen. Nat Rev Microbiol 2009; 7:736-47. [PMID: 19756012 PMCID: PMC3384523 DOI: 10.1038/nrmicro2208] [Citation(s) in RCA: 463] [Impact Index Per Article: 30.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Leptospirosis is a zoonotic disease that has emerged as an important cause of morbidity and mortality among impoverished populations. One hundred years after the discovery of the causative spirochaetal agent, little is understood about Leptospira spp. pathogenesis, which in turn has hampered the development of new intervention strategies to address this neglected disease. However, the recent availability of complete genome sequences for Leptospira spp. and the discovery of genetic tools for their transformation have led to important insights into the biology of these pathogens and their pathogenesis. We discuss the life cycle of the bacterium, the recent advances in our understanding and the implications for the future prevention of leptospirosis.
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Affiliation(s)
- Albert I. Ko
- Division of Infectious Disease, Weill Medical College of Cornell University, New York, USA
- Gonçalo Moniz Research Centre, Oswaldo Cruz Foundation, Brazilian Ministry of Health, Salvador, Brazil
| | - Cyrille Goarant
- Institut Pasteur de Nouvelle-Calédonie, Laboratoire de Recherche en Bactériologie, Nouméa, New-Caledonia
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Singh A, Kushwaha HR, Sharma P. Molecular modelling and comparative structural account of aspartyl beta-semialdehyde dehydrogenase of Mycobacterium tuberculosis (H37Rv). J Mol Model 2008; 14:249-63. [PMID: 18236087 DOI: 10.1007/s00894-008-0267-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2007] [Accepted: 01/03/2008] [Indexed: 11/29/2022]
Abstract
Aspartyl beta-semialdehyde dehydrogenase (ASADH) is an important enzyme, occupying the first branch position of the biosynthetic pathway of the aspartate family of amino acids in bacteria, fungi and higher plants. It catalyses reversible dephosphorylation of L: -beta-aspartyl phosphate (betaAP) to L: -aspartate-beta-semialdehyde (ASA), a key intermediate in the biosynthesis of diaminopimelic acid (DAP)-an essential component of cross linkages in bacterial cell walls. Since the aspartate pathway is unique to plants and bacteria, and ASADH is the key enzyme in this pathway, it becomes an attractive target for antimicrobial agent development. Therefore, with the objective of deducing comparative structural models, we have described a molecular model emphasizing the uniqueness of ASADH from Mycobacterium tuberculosis (H37Rv) that should generate insights into the structural distinctiveness of this protein as compared to structurally resolved ASADH from other bacterial species. We find that mtASADH exhibits structural features common to bacterial ASADH, while other structural motifs are not present. Structural analysis of various domains in mtASADH reveals structural conservation among all bacterial ASADH proteins. The results suggest that the probable mechanism of action of the mtASADH enzyme might be same as that of other bacterial ASADH. Analysis of the structure of mtASADH will shed light on its mechanism of action and may help in designing suitable antagonists against this enzyme that could control the growth of Mycobacterium tuberculosis.
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Affiliation(s)
- Anupama Singh
- Centre of Computational Biology and Bioinformatics (CCBB), School of Information Technology, Jawaharlal Nehru University, New Delhi, 110067, India
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Guégan R, Camadro JM, Saint Girons I, Picardeau M. Leptospira spp. possess a complete haem biosynthetic pathway and are able to use exogenous haem sources. Mol Microbiol 2003; 49:745-54. [PMID: 12864856 DOI: 10.1046/j.1365-2958.2003.03589.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Unlike the spirochetes Borrelia burgdorferi and Treponema pallidum, Leptospira spp. contain genes encoding the enzymes for most biosynthetic pathways. In this study, we describe the first haem biosynthetic pathway genes in the order Spirochaetales. Sequence analysis of the L. interrogans genome shows that all haem biosynthetic genes (hemA, heml, hemB, hemC, hemE, hemN, hemY and hemH) are clustered in a 15 kb region of the CII secondary chromosome. Although no hemD homologue (encoding uroporphyrinogen III synthase) was found in the genome, the L. interrogans hemC gene (encoding porphobilinogen deaminase) was able to restore uroporphyrinogen III synthase activity in an Escherichia coli Delta hemD mutant, suggesting that the L. interrogans hemC gene encodes a bifunctional enzyme. Similarly, we show that the L. interrogans hemH gene (encoding ferrochelatase, the terminal enzyme of the haem biosynthetic pathway) is able to complement a ferrochelatase-defective E. coli Delta hemH mutant. Further investigation of ferrochelatases was undertaken in both saprophytic and pathogenic species of Leptospira. Ferrochelatase activity of 2.3 +/- 0.1 nmol h-1 mg-1 (in comparison with 0.25 +/- 0.02 nmol h-1 mg-1 in E. coli) was found in membrane fractions of pathogenic and saprophytic species, suggesting that ferrochelatase is a membrane-associated protein. Leptospira biflexa allelic exchange mutants containing an inactivated hemH gene were recovered only when exogenous haemin was present. The results indicate that haem is an essential growth factor for Leptospira, and that these spirochetes are capable of both de novo synthesis or uptake of haem. This may have implications in a better understanding of the pathogenesis of Leptospira.
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Affiliation(s)
- Rozenn Guégan
- Unité de Bactériologie Moléculaire et Médicale, Institut Pasteur, Paris, France
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Bauby H, Saint Girons I, Picardeau M. Construction and complementation of the first auxotrophic mutant in the spirochaete Leptospira meyeri. MICROBIOLOGY (READING, ENGLAND) 2003; 149:689-693. [PMID: 12634337 DOI: 10.1099/mic.0.26065-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In bacteria, the first reaction of the tryptophan biosynthetic pathway involves the conversion of chorismate and glutamine to anthranilate by the action of anthranilate synthase, which is composed of the alpha (trpE gene product) and beta (trpG gene product) subunits. In this study, the tryptophan biosynthetic gene trpE of the spirochaete Leptospira meyeri was interrupted by a kanamycin-resistance cassette by homologous recombination. The trpE double cross-over mutant was not able to grow on solid or in liquid EMJH medium. In contrast, the trpE mutant showed a wild-type phenotype when tryptophan or anthranilate was added to the media, therefore showing that disruption of the L. meyeri trpE gene resulted in tryptophan auxotrophy. The authors have also characterized a second selectable marker that allows the construction of a spectinomycin-resistant L. meyeri-E. coli shuttle vector and the functional complementation of the L. meyeri trpE mutant.
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Affiliation(s)
- Hélène Bauby
- Unité de Bactériologie Moléculaire et Médicale, Institut Pasteur, 28 rue du docteur Roux, 75724 Paris Cedex 15, France
| | - Isabelle Saint Girons
- Unité de Bactériologie Moléculaire et Médicale, Institut Pasteur, 28 rue du docteur Roux, 75724 Paris Cedex 15, France
| | - Mathieu Picardeau
- Unité de Bactériologie Moléculaire et Médicale, Institut Pasteur, 28 rue du docteur Roux, 75724 Paris Cedex 15, France
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Bourhy P, Saint Girons I. Localization of the Leptospira interrogans metF gene on the CII secondary chromosome. FEMS Microbiol Lett 2000; 191:259-63. [PMID: 11024273 DOI: 10.1111/j.1574-6968.2000.tb09349.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
An open reading frame of 885 nucleotides was identified as the Leptospira interrogans metF gene. The deduced amino acid sequence (294 amino acids) showed similarities with Escherichia coli methylene tetrahydrofolate reductase (MetF or MTHFR) (33% identity) and with the N-terminal part of human MTHFR (33% identity). The L. interrogans metF gene complements an E. coli metF mutant to prototrophy, suggesting the functionality of the folate branch converging to form methionine. In addition, the L. interrogans MetF was found to be thermolabile. The metF gene belonged to the CII secondary chromosome, in contrast to the previously isolated metY and metX genes, which have been localized to the CI chromosome of Leptospira sp.
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Affiliation(s)
- P Bourhy
- Unité de Bactériologie Moléculaire et Médicale, Institut Pasteur, 28 rue du docteur Roux, 75724 Cedex 15, Paris, France
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Girons IS, Bourhy P, Ottone C, Picardeau M, Yelton D, Hendrix RW, Glaser P, Charon N. The LE1 bacteriophage replicates as a plasmid within Leptospira biflexa: construction of an L. biflexa-Escherichia coli shuttle vector. J Bacteriol 2000; 182:5700-5. [PMID: 11004167 PMCID: PMC94690 DOI: 10.1128/jb.182.20.5700-5705.2000] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have discovered that LE1, one of the plaque-forming phages previously described as lytic for the Leptospira biflexa saprophytic spirochete (I. Saint Girons, D. Margarita, P. Amouriaux, and G. Baranton, Res. Microbiol. 141:1131-1138, 1990), was indeed temperate. LE1 was found to be unusual, as Southern blot analysis indicated that it is one of the few phages to replicate in the prophage state as a circular plasmid. The unavailability of such small endogenous replicons has hindered genetic experimentation in Leptospira. We have developed a shuttle vector with DNA derived from LE1. Random LE1 DNA fragments were cloned into a pGEM 7Zf(+) derivative devoid of most of the bla gene but carrying a kanamycin resistance marker from the gram-positive bacterium Enterococcus (Streptococcus) faecalis. These constructs were transformed into L. biflexa strain Patoc 1 by electroporation, giving rise to kanamycin-resistant transformants. A 2.2-kb fragment from LE1 was responsible for replication of the vector in L. biflexa. However, a larger region including an intact parA gene homologue was necessary for the stability of the shuttle vector. Direct repeats and AT-rich regions characterized the LE1 origin of replication. Our data indicate that the replicon derived from the LE1 leptophage, together with the kanamycin resistance gene, is a promising tool with which to develop the genetics of Leptospira species.
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Affiliation(s)
- I S Girons
- Unité de Bactériologie Moléculaire et Médicale, Institut Pasteur, 75724 Paris Cedex 15, France.
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Zhang W, Jiang W, Zhao G, Yang Y, Chiao J. Sequence analysis and expression of the aspartokinase and aspartate semialdehyde dehydrogenase operon from rifamycin SV-producing amycolatopsis mediterranei. Gene 1999; 237:413-9. [PMID: 10521665 DOI: 10.1016/s0378-1119(99)00307-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A approximately 4.8 kb KpnI fragment, from the upstream region of the methylmalonyl-CoA mutase gene (mutAB) of rifamycin SV-producing Amycolatopsis mediterranei, was cloned and partially sequenced. Codon preference analysis showed three complete ORFs. ORF2 is internal to ORF1, and encodes a polypeptide corresponding to 172 amino acids, whereas ORF1 encodes a polypeptide of 421 amino acids. They were identified as the encoding genes of aspartokinase alpha- and beta-subunits by comparing the amino acid sequences with those in the database. The downstream ORF3, whose start codon was overlapped with the stop codon of both ORF1 and ORF2 by 1 bp, was identified as the aspartate semialdehyde dehydrogenase gene (asd), encoding a polypeptide of 346 amino acids. Subclones containing either the ask gene or the asd gene were constructed, in which the genes could be expressed under Lac promoters. Two subclones could transform E. coli CGSC 5074 (ask-) and E. coli X6118 (asd-) to prototrophy, supporting the functional assignments. Southern hybridisation indicated that the approximately 4.8 kb sequenced region represented a continuous segment in the A. mediterranei chromosome. It is concluded that ask and asd genes are present in an operon in A. mediterranei, and therefore that organisation of these two genes is the same as in most gram-positive bacteria, such as Mycobacteria, Corynebacterium glutamicum and Bacillus subtilis, but is different from Streptomyces akiyoshiensis.
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Affiliation(s)
- W Zhang
- Department of Microbiology, Shanghai Institute of Plant Physiology, Academia Sinica, 200032 Shanghai, People's Republic of China.
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13
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A polyprotein precursor of two mitochondrial enzymes in Neurospora crassa. Gene structure and precursor processing. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)37179-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Cirillo JD, Weisbrod TR, Pascopella L, Bloom BR, Jacobs WR. Isolation and characterization of the aspartokinase and aspartate semialdehyde dehydrogenase operon from mycobacteria. Mol Microbiol 1994; 11:629-39. [PMID: 7910936 DOI: 10.1111/j.1365-2958.1994.tb00342.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Diaminopimelic acid (DAP) is a major component of the peptidoglycan layer of the mycobacterial cell wall. The mycobacterial cell wall has been implicated as a potential virulence factor and is highly immunogenic. The pathway for biosynthesis of DAP may serve as a target in the design of antimycobacterial agents and construction of in vivo selection systems. Despite its significance, this biosynthetic pathway is poorly understood in mycobacteria. In order to develop a better understanding of mycobacterial DAP biosynthesis, the aspartate semialdehyde dehydrogenase (asd) genes of Mycobacterium smegmatis, bacille Calmette-Guerin (BCG), Mycobacterium avium, Mycobacterium leprae, and Mycobacterium tuberculosis were isolated. The M. smegmatis asd gene was isolated by complementation in Escherichia coli. This gene was then used to isolate the asd genes from other mycobacteria. The asd-complementing fragments from BCG and M. smegmatis were sequenced. An open reading frame upstream of the mycobacterial asd gene was identified as the mycobacterial aspartokinase gene (ask). Primer extension analysis revealed that the only transcriptional start in this region is found 5' of the ask gene. This observation indicates that the mycobacterial ask and asd genes are in an operon.
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Affiliation(s)
- J D Cirillo
- Howard Hughes Medical Institute, Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York 10461
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Zuerner RL, Herrmann JL, Saint Girons I. Comparison of genetic maps for two Leptospira interrogans serovars provides evidence for two chromosomes and intraspecies heterogeneity. J Bacteriol 1993; 175:5445-51. [PMID: 7690025 PMCID: PMC206600 DOI: 10.1128/jb.175.17.5445-5451.1993] [Citation(s) in RCA: 84] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Genetic maps were constructed for Leptospira interrogans serovars icterohaemorrhagiae and pomona. Previously we independently constructed physical maps of the genomes for these two serovars. The genomes of both serovars consist of a large replicon (4.4 to 4.6 Mb) and a small replicon (350 kb). Genes were localized on the physical maps by using Southern blot analysis with specific probes. Among the probes used were genes encoding a variety of essential enzymes and genes usually found near bacterial chromosomal replication origins. Most of the essential genes are on the larger replicon of each serovar. However, the smaller replicons of both serovars contain the asd gene. The asd gene encodes aspartate beta-semialdehyde dehydrogenase, an enzyme essential in amino acid and cell wall biosyntheses. The finding that both L. interrogans replicons contain essential genes suggests that both replicons are chromosomes. Comparison of the genetic maps of the larger replicons of the two serovars showed evidence of large rearrangements. These data show that there is considerable intraspecies heterogeneity in L. interrogans.
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Affiliation(s)
- R L Zuerner
- National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, Iowa 50010
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Chen N, Jiang S, Klein D, Paulus H. Organization and nucleotide sequence of the Bacillus subtilis diaminopimelate operon, a cluster of genes encoding the first three enzymes of diaminopimelate synthesis and dipicolinate synthase. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)98372-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Roten CA, Karamata D. Endogenous synthesis of peptidoglycan in eukaryotic cells; a novel concept involving its essential role in cell division, tumor formation and the biological clock. EXPERIENTIA 1992; 48:921-31. [PMID: 1426143 DOI: 10.1007/bf01919139] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Degradation products of peptidoglycan, the universal bacterial cell wall constituent, were previously found in animal tissues and urine. Reassessment and quantitative analysis of available data lead to an original concept, i.e. that eukaryotic cells synthesize peptidoglycan. We present a model in which this endogenously synthesized peptidoglycan is essential for the processes of eukaryotic cell division and sleep induction in animals. Genes for peptidoglycan metabolism, like those for lysine biosynthesis in plants, are probably inherited from endosymbiotic bacteria, the ancestors of mitochondria and chloroplasts. Corollaries of this concept, i.e. roles for peptidoglycan metabolism in tumor formation and in the biological clock, are supported by abundant evidence. We propose that many interactions between bacteria and eukaryotes are conditioned by their common genetic heritage.
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Affiliation(s)
- C A Roten
- Institut de génétique et de biologie microbiennes, Lausanne, Switzerland
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