Sexuality in Prokaryotes
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MBL Lectures in Biology,vol.7.
10,345 s.,grafy,obr. : Bibliog.,rejstřík.
Osmotically inducible protein (OsmC) and organic hydroperoxide resistance protein (Ohr) are small, thiol-dependent peroxidases that comprise a family of prokaryotic protective proteins central to the defense against deleterious effects of organic hydroperoxides, which are reactive molecules that are formed during interactions between the host immune system and pathogens. Trichomonas vaginalis, a sexually transmitted parasite of humans, possesses OsmC homologues in its hydrogenosomes, anaerobic mitochondrial organelles that harbor enzymes and pathways that are sensitive to oxidative damage. The glycine decarboxylase complex (GDC), which consists of four proteins (i.e., L, H, P and T), is in eukaryotes exclusively mitochondrial enzymatic system that catalyzes oxidative decarboxylation and deamination of glycine. However, trichomonad hydrogenosomes contain only the L and H proteins, whose physiological functions are unknown. Here, we found that the hydrogenosomal L and H proteins constitute a lipoate-dependent redox system that delivers electrons from reduced nicotinamide adenine dinucleotide (NADH) to OsmC for the reductive detoxification of peroxides. Our searches of genome databases revealed that, in addition to prokaryotes, homologues of OsmC/Ohr family proteins with predicted mitochondrial localization are present in various eukaryotic lineages. Therefore, we propose that the novel OsmC-GDC-based redox system may not be limited to T. vaginalis.
- MeSH
- axenická kultura MeSH
- Escherichia coli genetika metabolismus MeSH
- exprese genu MeSH
- fylogeneze MeSH
- I. fáze biotransformace genetika MeSH
- kinetika MeSH
- klonování DNA MeSH
- mitochondrie metabolismus ultrastruktura MeSH
- oxidace-redukce MeSH
- peroxid vodíku metabolismus MeSH
- peroxidasy genetika metabolismus MeSH
- protozoální proteiny genetika metabolismus MeSH
- rekombinantní proteiny genetika metabolismus MeSH
- sekvence aminokyselin MeSH
- sekvenční homologie aminokyselin MeSH
- sekvenční seřazení MeSH
- systém štěpení glycinu genetika metabolismus MeSH
- Trichomonas vaginalis genetika metabolismus ultrastruktura MeSH
- vazba proteinů MeSH
- Publikační typ
- časopisecké články MeSH
Iron-sulfur flavoproteins (Isf) are flavin mononucleotide (FMN)- and FeS cluster-containing proteins commonly encountered in anaerobic prokaryotes. However, with the exception of Isf from Methanosarcina thermophila, which participates in oxidative stress management by removing oxygen and hydrogen peroxide, none of these proteins has been characterized in terms of function. Trichomonas vaginalis, a sexually transmitted eukaryotic parasite of humans, was found to express several iron-sulfur flavoprotein (TvIsf) homologs in its hydrogenosomes. We show here that in addition to having oxygen-reducing activity, the recombinant TvIsf also functions as a detoxifying reductase of metronidazole and chloramphenicol, both of which are antibiotics effective against a variety of anaerobic microbes. TvIsf can utilize both NADH and reduced ferredoxin as electron donors. Given the prevalence of Isf in anaerobic prokaryotes, we propose that these proteins are central to a novel defense mechanism against xenobiotics.
- MeSH
- antitrichomonádové látky farmakologie MeSH
- ferredoxiny metabolismus MeSH
- flavoproteiny metabolismus MeSH
- geny hub MeSH
- katalýza MeSH
- léková rezistence MeSH
- metronidazol chemie farmakologie MeSH
- molekulární sekvence - údaje MeSH
- NAD metabolismus MeSH
- proteiny obsahující železo a síru metabolismus MeSH
- sekvence aminokyselin MeSH
- subcelulární frakce účinky léků metabolismus MeSH
- Trichomonas vaginalis metabolismus MeSH
- vodík metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
... OF LIFE 22 -- 24 Early Earth and the Origin of Life 486 -- 2 The Chemical Context of Life 25 25 Prokaryotes ... ... 727 -- UNIT THREE 35 Control Systems in Plants 750 -- THE GENE 222 -- UNIT SEVEN -- 12 Meiosis and Sexual ... ... an overview of prokaryotic life 498 -- Archaea and Bacteria are the two main branches of prokaryotic ... ... evolution 499 -- The success of prokaryotic life is based on diverse adaptations of form and function ... ... systematics is leading to a phylogenetic classification of prokaryotes 508 -- Prokaryotes continue to ...
Fourth edition 1206, 32 stran : ilustrace ; 29 cm
... McCance Prokaryotes and Eukaryotes, 2 Cellular Functions, 2 -- Structure and Function of Cellular Components ... ... Life Conditions, 410 Environmental-Lifestyle Factors, 413 Tobacco Use, 413 Diet, 414 -- Infection, Sexual ... ... McCance Abnormalities of Reproductive Tract Development, 800 -- Alterations of Sexual Maturation, 802 ... ... McCance Alterations of Sexual Maturation, 885 -- Delayed Puberty, 886 Precocious Puberty, 886 Disorders ... ... -- Disorders of the Scrotum, Testis, and Epididymis, 891 -- Disorders of the Prostate Gland, 897 Sexual ...
7th ed. xxvi, 1810 s. : il. (převážně barev.) ; 29 cm
- MeSH
- biomedicínský výzkum MeSH
- dítě MeSH
- dospělí MeSH
- fyziologie MeSH
- klinické lékařství MeSH
- patologie MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- Konspekt
- Experimentální medicína
- Učební osnovy. Vyučovací předměty. Učebnice
- NLK Obory
- patologie
- fyziologie
- NLK Publikační typ
- učebnice vysokých škol
- kolektivní monografie
... Products 585 -- The Regulation of Gene Expression -- Chapter 23 Regulation of Gene Expression in Prokaryotes ... ... BASIS OF HEREDITY 22 -- An Acciderit in Cell Division 22 The Cell as the Basic Unit of Fife 23 The Prokaryotic ... ... the Double Helix 230 -- DNA Structure: Negative Supercoils in Vivo 232 Chromosome Structure in Prokaryotes ... ... Specialized Transduction 467 Transduction and Gene Mapping 470 The Evolutionary Significance of Sexuality ... ... Kuroda 613 -- 23 REGULATION OF GENE EXPRESSION -- IN PROKARYOTES AND THEIR VIRUSES 615 D’Hérelle’s Dream ...
2nd ed. xviii, 876 s. : il.
... - Similarity in Function and Composition of All Cells 9 Basic Cell Types 10 -- Perspective 1.3: Prokaryotes ... ... in the Guinness Book of Records 12 -- Some Cell Types Appear to Be Intermediate Between Prokaryotes ... ... Eukaryotic Cells 70 -- Energy Is Generated by Mitochondria and Chloroplasts 71 -- Cell Movement—Prokaryotic ... ... 262 -- Prokaryotes Whose Cell Walls Lack Peptidoglycan 264 -- Archaebacteria Differ from Eubacteria ... ... 273 -- Algae Are Typical Eukaryotic Organisms 274 -- Algae Reproduce by Both Asexual and Sexual Means ...
XXVIII, 812 s. : il. ; 32 cm
... Chemical Composition of the Cell Organic Cell Compounds Proteins Nucleic Acids Saccharides Lipids Prokaryotic ... ... and Eukaryotic Cells A Survey of Differences between Prokaryotic and Eukaryotic Cells, Biomembranes ... ... Nutrition and Digestion Excretory System Nervous Systems Sensory Functions Hormonal Regulation Locomotion Sexual ... ... GENETICS Heredity and Variability Character and Phenotype Gene and Genotype Gene and its Expression Prokaryotic ...
2nd expanded ed. 91 s. : il. ; 30 cm
- Konspekt
- Obecná biologie
- Učební osnovy. Vyučovací předměty. Učebnice
- NLK Obory
- biologie
- NLK Publikační typ
- učebnice vysokých škol
... PROKARYOTIC AND EUKARYOTIC CELLS 22 -- 5. BIOMEMBRANES AND MEMBRANE ORGANELLES 23 -- 6. ... ... SEXUAL REPRODUCTION 40 -- Ontogenic Development 41 -- 6. GENETICS 41 -- 1. ... ... PROKARYOTIC AND EUKARYOTIC CHROMOSOMES AND PLASMIDS 43 -- 6. ...
84 s. : il. ; 30 cm
Sexual reproduction and clonality in eukaryotes are mostly seen as exclusive, the latter being rather exceptional. This view might be biased by focusing almost exclusively on metazoans. We analyze and discuss reproduction in the context of extant eukaryotic diversity, paying special attention to protists. We present results of phylogenetically extended searches for homologs of two proteins functioning in cell and nuclear fusion, respectively (HAP2 and GEX1), providing indirect evidence for these processes in several eukaryotic lineages where sex has not been observed yet. We argue that (i) the debate on the relative significance of sex and clonality in eukaryotes is confounded by not appropriately distinguishing multicellular and unicellular organisms; (ii) eukaryotic sex is extremely widespread and already present in the last eukaryotic common ancestor; and (iii) the general mode of existence of eukaryotes is best described by clonally propagating cell lines with episodic sex triggered by external or internal clues. However, important questions concern the relative longevity of true clonal species (i.e., species not able to return to sexual procreation anymore). Long-lived clonal species seem strikingly rare. We analyze their properties in the light of meiotic sex development from existing prokaryotic repair mechanisms. Based on these considerations, we speculate that eukaryotic sex likely developed as a cellular survival strategy, possibly in the context of internal reactive oxygen species stress generated by a (proto) mitochondrion. Thus, in the context of the symbiogenic model of eukaryotic origin, sex might directly result from the very evolutionary mode by which eukaryotic cells arose.
- MeSH
- eukaryotické buňky fyziologie MeSH
- fúze buněk MeSH
- genom MeSH
- meióza MeSH
- mitochondrie metabolismus MeSH
- molekulární sekvence - údaje MeSH
- reaktivní formy kyslíku metabolismus MeSH
- rozmnožování * MeSH
- sekvenční analýza DNA MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
