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Yarlett N, Jarroll EL, Morada M, Lloyd D. Protists: Eukaryotic single-celled organisms and the functioning of their organelles. Adv Microb Physiol 2024; 84:243-307. [PMID: 38821633 DOI: 10.1016/bs.ampbs.2024.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2024]
Abstract
Organelles are membrane bound structures that compartmentalize biochemical and molecular functions. With improved molecular, biochemical and microscopy tools the diversity and function of protistan organelles has increased in recent years, providing a complex panoply of structure/function relationships. This is particularly noticeable with the description of hydrogenosomes, and the diverse array of structures that followed, having hybrid hydrogenosome/mitochondria attributes. These diverse organelles have lost the major, at one time, definitive components of the mitochondrion (tricarboxylic cycle enzymes and cytochromes), however they all contain the machinery for the assembly of Fe-S clusters, which is the single unifying feature they share. The plasticity of organelles, like the mitochondrion, is therefore evident from its ability to lose its identity as an aerobic energy generating powerhouse while retaining key ancestral functions common to both aerobes and anaerobes. It is interesting to note that the apicoplast, a non-photosynthetic plastid that is present in all apicomplexan protozoa, apart from Cryptosporidium and possibly the gregarines, is also the site of Fe-S cluster assembly proteins. It turns out that in Cryptosporidium proteins involved in Fe-S cluster biosynthesis are localized in the mitochondrial remnant organelle termed the mitosome. Hence, different organisms have solved the same problem of packaging a life-requiring set of reactions in different ways, using different ancestral organelles, discarding what is not needed and keeping what is essential. Don't judge an organelle by its cover, more by the things it does, and always be prepared for surprises.
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Affiliation(s)
- Nigel Yarlett
- Haskins Laboratories, Pace University, New York, NY, United States; The Department of Chemistry and Physical Sciences, Pace University, New York, NY, United States.
| | - Edward L Jarroll
- Department of Biological Sciences, CUNY-Lehman College, Bronx, NY, United States
| | - Mary Morada
- Haskins Laboratories, Pace University, New York, NY, United States
| | - David Lloyd
- Schools of Biosciences and Engineering, Cardiff University, Wales, United Kingdom
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Bínová E, Bína D, Nohýnková E. DNA content in Acanthamoeba during two stress defense reactions: Encystation, pseudocyst formation and cell cycle. Eur J Protistol 2020; 77:125745. [PMID: 33218872 DOI: 10.1016/j.ejop.2020.125745] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 08/22/2020] [Accepted: 10/19/2020] [Indexed: 12/01/2022]
Abstract
During environmental stress, the vegetative cells of the facultative pathogenic amoeba Acanthamoeba castellanii reversibly differentiate into resistant dormant stages, namely, cysts or pseudocysts. The type of resistant stage depends on the nature and duration of the stressor. Cell differentiation is accompanied by changes in morphology and cellular metabolism. Moreover, cell differentiation is also expected to be closely linked to the regulation of the cell cycle and, thus, to cellular DNA content. While the existence of the resistant stages in A. castellanii is well known, there is no consensus regarding the relationship between differentiation and cell cycle progression. In the present work, we used flow cytometry analysis to explore the changes in the DNA content during Acanthamoeba encystation and pseudocyst formation. Our results strongly indicate that A. castellanii enters encystation from the G2 phase of the cell cycle. In contrast, differentiation into pseudocysts can begin in the G1 and G2 phases. In addition, we present a phylogenetic analysis and classification of the main cell cycle regulators, namely, cyclin-dependent kinases and cyclins that are found in the genome of A. castellanii.
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Affiliation(s)
- Eva Bínová
- Institute of Immunology and Microbiology, First Faculty of Medicine, Charles University, Studnickova 7, 128 00 Prague 2, Czech Republic
| | - David Bína
- Faculty of Science, University of South Bohemia, Branišovská 1760 and The Czech Academy of Sciences, Biology Centre, Branišovská 31, 370 05 České Budějovice, Czech Republic
| | - Eva Nohýnková
- Institute of Immunology and Microbiology, First Faculty of Medicine, Charles University, Studnickova 7, 128 00 Prague 2, Czech Republic.
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Gilbert K, Hammond KD, Brodsky VY, Lloyd D. An appreciation of the prescience of Don Gilbert (1930-2011): master of the theory and experimental unravelling of biochemical and cellular oscillatory dynamics. Cell Biol Int 2020; 44:1283-1298. [PMID: 32162760 DOI: 10.1002/cbin.11341] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 03/08/2020] [Indexed: 11/08/2022]
Abstract
We review Don Gilbert's pioneering seminal contributions that both detailed the mathematical principles and the experimental demonstration of several of the key dynamic characteristics of life. Long before it became evident to the wider biochemical community, Gilbert proposed that cellular growth and replication necessitate autodynamic occurrence of cycles of oscillations that initiate, coordinate and terminate the processes of growth, during which all components are duplicated and become spatially re-organised in the progeny. Initiation and suppression of replication exhibit switch-like characteristics, that is, bifurcations in the values of parameters that separate static and autodynamic behaviour. His limit cycle solutions present models developed in a series of papers reported between 1974 and 1984, and these showed that most or even all of the major facets of the cell division cycle could be accommodated. That the cell division cycle may be timed by a multiple of shorter period (ultradian) rhythms, gave further credence to the central importance of oscillatory phenomena and homeodynamics as evident on multiple time scales (seconds to hours). Further application of the concepts inherent in limit cycle operation as hypothesised by Gilbert more than 50 years ago are now validated as being applicable to oscillatory transcript, metabolite and enzyme levels, cellular differentiation, senescence, cancerous states and cell death. Now, we reiterate especially for students and young colleagues, that these early achievements were even more exceptional, as his own lifetime's work on modelling was continued with experimental work in parallel with his predictions of the major current enterprises of biological research.
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Affiliation(s)
- Kay Gilbert
- School of Biosciences, Cardiff University, Sir Martin Evans Building, Park Place, Cardiff, CF10 3AT, Wales, UK
| | | | - Vsevolod Y Brodsky
- Koltsov Institute of Developmental Biology, Russian Academy of Sciences, Moscow, 117808, Russia
| | - David Lloyd
- School of Biosciences, Cardiff University, Sir Martin Evans Building, Park Place, Cardiff, CF10 3AT, Wales, UK
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Lloyd D, Murray DB, Aon MA, Cortassa S, Roussel MR, Beckmann M, Poole RK. Temporal metabolic partitioning of the yeast and protist cellular networks: the cell is a global scale-invariant (fractal or self-similar) multioscillator. JOURNAL OF BIOMEDICAL OPTICS 2018; 24:1-17. [PMID: 30516036 PMCID: PMC6992908 DOI: 10.1117/1.jbo.24.5.051404] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 11/01/2018] [Indexed: 06/09/2023]
Abstract
Britton Chance, electronics expert when a teenager, became an enthusiastic student of biological oscillations, passing on this enthusiasm to many students and colleagues, including one of us (DL). This historical essay traces BC's influence through the accumulated work of DL to DL's many collaborators. The overall temporal organization of mass-energy, information, and signaling networks in yeast in self-synchronized continuous cultures represents, until now, the most characterized example of in vivo elucidation of time structure. Continuous online monitoring of dissolved gases by direct measurement (membrane-inlet mass spectrometry, together with NAD(P)H and flavin fluorescence) gives strain-specific dynamic information from timescales of minutes to hours as does two-photon imaging. The predominantly oscillatory behavior of network components becomes evident, with spontaneously synchronized cellular respiration cycles between discrete periods of increased oxygen consumption (oxidative phase) and decreased oxygen consumption (reductive phase). This temperature-compensated ultradian clock provides coordination, linking temporally partitioned functions by direct feedback loops between the energetic and redox state of the cell and its growing ultrastructure. Multioscillatory outputs in dissolved gases with 13 h, 40 min, and 4 min periods gave statistical self-similarity in power spectral and relative dispersional analyses: i.e., complex nonlinear (chaotic) behavior and a functional scale-free (fractal) network operating simultaneously over several timescales.
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Affiliation(s)
- David Lloyd
- Cardiff University, School of Biosciences, Cardiff, Wales, United Kingdom
| | - Douglas B. Murray
- Keio University, Institute for Advanced Biosciences, Tsuruoka, Japan
| | - Miguel A. Aon
- National Institutes of Health, National Institute on Aging, Laboratory of Cardiovascular Science, Baltimore, Maryland, United States
| | - Sonia Cortassa
- National Institutes of Health, National Institute on Aging, Laboratory of Cardiovascular Science, Baltimore, Maryland, United States
| | - Marc R. Roussel
- University of Lethbridge, Alberta RNA Research and Training Institute and Department of Chemistry and Biochemistry, Alberta, Canada
| | - Manfred Beckmann
- Institute of Biological, Environmental and Rural, Sciences, Aberystwyth, Wales, United Kingdom
| | - Robert K. Poole
- University of Sheffield, Department of Molecular Biology and Biotechnology, Firth Court, Western Bank, Sheffield, United Kingdom
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Abstract
Fundamental understanding of life depends on both structural and functional details at the molecular level. Continually improving means of measurement of spatial and dynamic properties of biochemical constituents and cellular components complement studies of whole organisms. Integration of the interaction of components to provide coherent behaviour depends on highly elaborate orchestration in space and time. Whereas spatial information on a nanometre resolution is available, and fast dynamic analyses provide biochemical reaction rates measured in nanoseconds, functional coordination of the system requires integrated time dependence. While we are well aware of the special complexity of living organisms, appreciation of temporal scales and their organisation in time is still fragmentary. This article summarises current developments in research on biological time on scales from nanoseconds to years, the networks that connect different time domains and the oscillations, rhythms and biological clocks that coordinate and synchronise the complexity of the living state. “It is the pattern maintained by this homeostasis, which is the touchstone of our personal identity. Our tissues change as we live: the food we eat and the air we breathe become flesh of our flesh, and bone of our bone, and the momentary elements of our flesh and bone pass out of our body every day with our excreta. We are but whirlpools in a river of ever-flowing water. We are not the stuff that abides, but patterns that perpetuate themselves”60. Wiener, 1954 “What are called structures are slow processes of long duration, functions are quick processes of short duration”61. Von Bertalanffy, 1952
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Affiliation(s)
- David Lloyd
- Cardiff School of Biosciences, Wales, UK, and the Memphys Research Group, Biochemistry and Molecular Biology Department, at the University of Southern Denmark, Odense
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Lloyd D. Encystment in Acanthamoeba castellanii: a review. Exp Parasitol 2014; 145 Suppl:S20-7. [PMID: 24726698 DOI: 10.1016/j.exppara.2014.03.026] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 03/02/2014] [Accepted: 03/04/2014] [Indexed: 10/25/2022]
Abstract
Differentiation of Acanthamoeba castellanii trophozoites involves massive turnover of cellular components and remodelling of organelle structure and function so as to produce a cryptobiotic cell, resistant to desiccation, heat, freezing, and chemical treatments. This review presents a summary of a decade of research on the most studied aspects of the biochemistry of this process, with emphasis on problems of biocide and drug resistances, putative new targets, molecular and cell biology of the process of encystment, and the characteristics of the encysted state. As well as the intrinsic pathogenicity of the organism towards the cornea, and the ability of related species to invade the human brain, its propensity for harbouring and transmitting pathogenic bacteria and viruses is considerable and leads to increasing concerns. The long-term survival and resistance of cysts to drugs and biocides adds another layer of complexity to the problem of their elimination.
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Affiliation(s)
- David Lloyd
- School of Biosciences, Cardiff University, Cardiff, Wales CF10 3AT, UK.
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Sasidharan K, Amariei C, Tomita M, Murray DB. Rapid DNA, RNA and protein extraction protocols optimized for slow continuously growing yeast cultures. Yeast 2012; 29:311-22. [PMID: 22763810 DOI: 10.1002/yea.2911] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 06/07/2012] [Accepted: 06/07/2012] [Indexed: 11/09/2022] Open
Abstract
Conventional extraction protocols for yeast have been developed for relatively rapid-growing low cell density cultures of laboratory strains and often do not have the integrity for frequent sampling of cultures. Therefore, these protocols are usually inefficient for cultures under slow growth conditions or of non-laboratory strains. We have developed a combined mechanical and chemical disruption procedure using vigorous bead-beating that can consistently disrupt yeast cells (> 95%), irrespective of cell cycle and metabolic state. Using this disruption technique coupled with quenching, we have developed DNA, RNA and protein extraction protocols that are optimized for a large number of samples from slow-growing high-density industrial yeast cultures. Additionally, sample volume, the use of expensive reagents/enzymes, handling times and incubations were minimized. We have tested the reproducibility of our methods using triplicate/time-series extractions and compared these with commonly used protocols or commercially available kits. Moreover, we utilized a simple flow-cytometric approach to estimate the mitochondrial DNA copy number. Based on the results, our methods have shown higher reproducibility, yield and quality.
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Affiliation(s)
- Kalesh Sasidharan
- Institute for Advanced Biosciences, Keio University, Yamagata, Japan
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Lloyd D, Cortassa S, O'Rourke B, Aon MA. What yeast and cardiomyocytes share: ultradian oscillatory redox mechanisms of cellular coherence and survival. Integr Biol (Camb) 2012; 4:65-74. [PMID: 22143867 PMCID: PMC3348865 DOI: 10.1039/c1ib00124h] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The coherent and robust, yet sensitively adaptable, nature of organisms is an astonishing phenomenon that involves massive parallel processing and concerted network performance at the molecular level. Unravelling the dynamic complexities of the living state underlines the essential operation of ultradian oscillations, rhythms and clocks for the establishment and maintenance of functional order simultaneously on fast and slower timescales. Non-invasive monitoring of respiration, mitochondrial inner membrane potentials, and redox states (especially those of NAD(P)H, flavin, and the monochlorobimane complex of glutathione), even after more than 50 years research, continue to provide both new insights and biomedical applications. Experiments with yeast and in cardiac cells reveal astonishing parallels and similarities in their dynamic biochemical organization.
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Affiliation(s)
- David Lloyd
- School of Biosciences, Cardiff University, Museum Avenue, Cardiff CF10 3AT Wales, UK.
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Brodsky VY. Direct cell-cell communications and social behavior of cells in mammals, protists, and bacteria. Possible causes of multicellularity. Russ J Dev Biol 2009. [DOI: 10.1134/s1062360409020027] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Affiliation(s)
- David Lloyd
- Microbiology, BIOSI 1, Main Building, Cardiff University, PO Box 915, Cardiff CF10 3TL Wales, UK.
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Abstract
Ultradian rhythms are those that cycle many times in a day and are therefore measured in hours, minutes, seconds or even fractions of a second. In yeasts and protists, a temperature-compensated clock with a period of about an hour (30-90 minutes) provides the time base upon which all central processes are synchronized. A 40-minute clock in yeast times metabolic, respiratory and transcriptional processes, and controls cell division cycle progression. This system has at its core a redox cycle involving NAD(P)H and dithiol-disulfide interconversions. It provides an archetype for biological time keeping on longer time scales (e.g. the daily cycles driven by circadian clocks) and underpins these rhythms, which cannot be understood in isolation. Ultradian rhythms are the foundation upon which the coherent functioning of the organism depends.
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Affiliation(s)
- David Lloyd
- Microbiology, School of Biosciences, Cardiff University, Wales, UK.
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Brodsky VY. Direct cell-cell communication: a new approach derived from recent data on the nature and self-organisation of ultradian (circahoralian) intracellular rhythms. Biol Rev Camb Philos Soc 2005; 81:143-62. [PMID: 16336746 DOI: 10.1017/s1464793105006937] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2005] [Revised: 09/14/2005] [Accepted: 09/21/2005] [Indexed: 11/07/2022]
Abstract
Recent data concerning ultradian (circahoralian) intracellular rhythms are used to assess the biochemical mechanisms of direct cell-cell communication. New results and theoretical considerations suggest a fractal nature of ultradian rhythms and their self-organisation. The fundamental and innate nature of these rhythms relates to their self-similarity at different levels of cell and tissue organisation. They can be detected in cell-free systems as well as in cells and organs in vivo. Such rhythms are a means of finding an optimal state of cell function rather than achieving a state of absolute stability. As a consequence, oscillations, being irregular and numerous by the set of periods, are resilient to functional overload and injury. Recent data on the maintenance of their fractal structure and, especially on the selection of optimal periods are discussed. The positive role of chaotic dynamics is stressed. The ultradian rhythm of protein synthesis in hepatocytes in vitro was used as a marker of direct cell-cell communication. The system demonstrates cell cooperation and synchronisation throughout the cell population, and suggests that the ultradian rhythms are self-organised. These observations also led to the detection of mechanisms of direct cell-cell communication in which extracellular factors have an essential role. Experimental evidence indicated the involvement of gangliosides and/or catecholamines in this large-scale synchronisation of protein synthesis. The response of all, or a major part, of the cell population is important; after the initial trigger effect, a periodic pattern is retained for some time. The influence of Ca2+-dependent protein kinases on protein phosphorylation can be a final step in the phase modulation of rhythms during cell-cell synchronisation. The intercellular medium plays an important role in self-synchronisation of ultradian rhythms between individual cells. Low cooperative activity of hepatocytes of old rats resulted from altered composition of the intercellular medium rather than direct effects of animal and cellular ageing. Similarly, in the whole body, changes in levels of gangliosides and catecholamines in the blood serum, a natural intercellular medium, can be critical events in age-dependent changes of the serum and accordingly cell-cell synchronisation. Hepatocytes of old rats exhibit some of the properties of young cells following an increase in blood serum ganglioside level, as well as, in in vitro conditions, after the addition of gangliosides to the culture medium. Together with data on ultradian functional and metabolic rhythms, all the material reviewed here allows us to propose a mechanism of direct cell-cell cooperation via the medium in which the cells exist, that supplements the nervous and hormonal central regulation of organ functions. Ultradian intracellular rhythms may thus provide a finer framework within which the integrated dynamics of respiration, heart rate, brain activity, and even behavioural patterns, are brought to an optimal functional pattern. Innate and direct cell-cell cooperation may have been employed as a means of intercellular regulation during the course of metazoan evolution, that preceded nervous regulation and is presently retained in mammals.
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Affiliation(s)
- Vsevolod Ya Brodsky
- Institute of Developmental Biology, Russian Academy of Sciences, 26 Vavilov St., Moscow, GSP-1 119991, Russia.
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Lloyd D. Effects of uncoupling of mitochondrial energy conservation on the ultradian clock-driven oscillations in Saccharomyces cerevisiae continuous culture. Mitochondrion 2005; 3:139-46. [PMID: 16120353 DOI: 10.1016/j.mito.2003.08.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2003] [Revised: 08/26/2003] [Accepted: 08/27/2003] [Indexed: 10/27/2022]
Abstract
Protonophores have several different perturbative effects on dissolved O2 concentrations in continuous cultures of Saccharomyces cerevisiae. As well as uncoupling energy conservation from mitochondrial electron transport in vivo, they reset ultradian clock-driven respiratory oscillations and produce cell cycle effects. Thus, additions at low concentration (1.25 microM) of either m-chlorocarbonyl-cyanide phenylhydrazone (CCCP) or 5-chloro-3-t-butyl-2-chloro-4(1)-nitrosalicylanilide (S13) led to phase resetting of the 48 min ultradian clock-driven respiratory oscillations. At 2.5 microM CCCP or 4 microM S13, transient inhibition of oscillatory respiration (for 5 h) preceded synchronisation of the cell division cycle seen as a slow (9 h period) wave that enveloped the 48 min oscillation. At still higher concentrations of CCCP (5 microM), the cell division cycle was prolonged by about 7 h, and during this phase, the respiratory oscillation became undetectable. The significance of these observations with respect to the time-keeping functions of the ultradian clock is discussed.
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Affiliation(s)
- David Lloyd
- Microbiology (BIOSI 1), Cardiff University, P.O. Box 915, Cardiff, Wales CF10 3TL, UK.
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Lloyd D, Salgado LEJ, Turner MP, Suller MTE, Murray D. Cycles of mitochondrial energization driven by the ultradian clock in a continuous culture of Saccharomyces cerevisiae. MICROBIOLOGY (READING, ENGLAND) 2002; 148:3715-3724. [PMID: 12427961 DOI: 10.1099/00221287-148-11-3715] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A continuous culture of Saccharomyces cerevisiae IFO 0233, growing with glucose as the major carbon and energy source, shows oscillations of respiration with a period of 48 min. Samples taken at maxima and minima indicate that (i) periodic changes do not occur as a result of carbon depletion, (ii) intrinsic differences in respiratory activity occur in washed organisms and (iii) a respiratory inhibitor accumulates during respiratory oscillations. Plasma membrane and inner mitochondrial membranes generate transmembrane electrochemical potentials; changes in these can be respectively assessed using anionic or cationic fluorophores. Thus flow cytometric analyses indicated that an oxonol dye [DiBAC(4)(3); bis(1,3-dibutylbarbituric acid)trimethine oxonol] was excluded from yeasts to a similar extent (in >98% of the population) at all stages, showing that the plasma membrane potential was maintained at a steady value. However, uptake of Rhodamine 123 was greatest at that phase characterized by a low respiratory rate. Addition of uncouplers of energy conservation [CCCP (m-chlorocarbonylcyanide phenylhydrazone) or S-13(5-chloro-3-t-butyl-2-chloro-4(1)-nitrosalicylanilide)] to the continuous cultures increased the respiration, but had only a transient effect on the period of the oscillation. Electron microscopy showed changes in mitochondrial ultrastructure during the respiratory oscillation. At low respiration the cristae were more clearly defined due to swelling of the matrix; this corresponds to the 'orthodox' conformation. When respiration was high the mitochondrial configuration was 'condensed'. It has been shown previously that a temperature-compensated ultradian clock operates in S. cerevisiae. It is proposed that mitochondria undergo cycles of energization in response to energetic demands driven by this ultradian clock output.
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Affiliation(s)
- David Lloyd
- Microbiology (BIOSI 1, Main Building), Cardiff University, PO Box 915, Cardiff CF10 3TL, Wales, UK1
| | - L Eshantha J Salgado
- Microbiology (BIOSI 1, Main Building), Cardiff University, PO Box 915, Cardiff CF10 3TL, Wales, UK1
| | - Michael P Turner
- Microbiology (BIOSI 1, Main Building), Cardiff University, PO Box 915, Cardiff CF10 3TL, Wales, UK1
| | - Marc T E Suller
- Microbiology (BIOSI 1, Main Building), Cardiff University, PO Box 915, Cardiff CF10 3TL, Wales, UK1
| | - Douglas Murray
- School of Applied Science, University of the South Bank, 103 Borough Road, London SET 0AA, UK2
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Lloyd D, Eshantha L, Salgado J, Turner MP, Murray DB. Respiratory oscillations in yeast: clock-driven mitochondrial cycles of energization. FEBS Lett 2002; 519:41-4. [PMID: 12023015 DOI: 10.1016/s0014-5793(02)02704-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Respiratory oscillations in continuous yeast cultures can be accounted for by cyclic energization of mitochondria, dictated by the demands of a temperature-compensated ultradian clock with a period of 50 min. Inner mitochondrial membranes show both ultrastructural modifications and electrochemical potential changes. Electron transport components (NADH and cytochromes c and c oxidase) show redox state changes as the organisms cycle between their energized and de-energized phases. These regular cycles are transiently perturbed by uncouplers of energy conservation, with amplitudes more affected than period; that the characteristic period is restored after only one prolonged cycle, indicates that mitochondrial energy generation is not part of the clock mechanism itself, but is responding to energetic requirement.
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Affiliation(s)
- David Lloyd
- Microbiology (BIOSI 1, Main Building), Cardiff University, P.O. Box 915, Cardiff, UK.
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Abstract
The time structure of a biological system is at least as intricate as its spatial structure. Whereas we have detailed information about the latter, our understanding of the former is still rudimentary. As techniques for monitoring intracellular processes continuously in single cells become more refined, it becomes increasingly evident that periodic behaviour abounds in all time domains. Circadian timekeeping dominates in natural environments. Here the free-running period is about 24 h. Circadian rhythms in eukaryotes and prokaryotes allow predictive matching of intracellular states with environmental changes during the daily cycles. Unicellular organisms provide excellent systems for the study of these phenomena, which pervade all higher life forms. Intracellular timekeeping is essential. The presence of a temperature-compensated oscillator provides such a timer. The coupled outputs (epigenetic oscillations) of this ultradian clock constitute a special class of ultradian rhythm. These are undamped and endogenously driven by a device which shows biochemical properties characteristic of transcriptional and translational elements. Energy-yielding processes, protein turnover, motility and the timing of the cell-division cycle processes are all controlled by the ultradian clock. Different periods characterize different species, and this indicates a genetic determinant. Periods range from 30 min to 4 h. Mechanisms of clock control are being elucidated; it is becoming evident that many different control circuits can provide these functions.
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Affiliation(s)
- D Lloyd
- Microbiology Group (PABIO), University of Wales Cardiff, UK
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Ferreira GM, Hammond KD, Gilbert DA. Oscillatory variations in the amount of protein extractable from murine erythroleukemia cells: stimulation by insulin. Biosystems 1994; 32:183-90. [PMID: 7919115 DOI: 10.1016/0303-2647(94)90041-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The amount of protein extractable from murine erythroleukemia (MEL) cells varies in an oscillatory manner at high frequency and high amplitude as it does for several other cell lines. Moreover, the rhythm appears to be modulated in periodic fashion with respect to the mean, period and amplitude. The phenomenon thus seems to be universal and fundamental. Time series analyses support the view that several periodicities contribute to the observed protein rhythm. Insulin affects the dynamics as it does for both morphological and phosphorylation oscillations. Caution is necessary in the interpretation of 'specific activities' of cellular components and in electrophoretic studies wherein equal amounts of protein are applied to the wells in an effort to correct for random errors.
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Affiliation(s)
- G M Ferreira
- Department of Medical Biochemistry, Medical School, University of the Witwatersrand, Parktown, Johannesburg, South Africa
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Abstract
While it is generally acknowledged that modern science began with the quantification of time in the measurement of linear physical processes in space by Galileo and Newton, the biological sciences have only recently developed appropriate experimental and mathematical methods for the description of living systems in terms of processes of non-linear, recursive dynamics. We now recognize that living organisms have patterns of exquisitely timed processes that are as intricate as their spatial structure and organization. Self-similarities of life processes in time and space have evolved to generate an ensemble of oscillators within which analogous functions may be discerned on many different time scales. The increasing complexity of periodic relationships on and between the many levels of biological organization are uncovered by current research. Recent efforts to reformulate the foundation of physics from the quantum to the cosmological level by using the concept of information as the common denominator integrating time, structure and energy remind us of an apparently analogous suggestion in the chronobiological literature which also describes the periodic dynamics of living systems as information processing. In this paper we review the periodic processes of living systems on all levels from the molecular, genetic and cellular to the neuroendocrinological, behavioural and social domains. Biological rhythms may be conceptualized as the evolution of ever more complex dynamics of information transduction that optimize the temporal integrity, development, and survival of the organism.
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Affiliation(s)
- D Lloyd
- Microbiology Group (PABIO), University of Wales College of Cardiff, Wales, UK
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Abstract
Ultradian oscillations with periods between 5 min and 4 h have been described in cell-free extracts, single-celled eukaryotes, cultured cells and embryos. Whereas some of these potentially oscillatory systems (e.g. glycolysis) may only exhibit this type of behaviour rarely if at all in vivo, other ultradian oscillators in lower eukaryotes are rhythms and probably have timekeeping functions. Rhythms with ultradian periods of 10 min to 20 h in oxygen consumption and carbon dioxide production have also been studied in endotherm animals: these rhythms may be modified by variations of environmental parameters and by circadian and infradian synchronizers. Interspecies and interstrain differences strongly suggest that these rhythms are endogenous and have a genetic origin. We suggest that the temporal organization of biochemical and physiological processes facilitates optimization of thermodynamic maintenance of the organism within the random fluctuations of its physicochemical environment and contributes to genetic selection.
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Affiliation(s)
- D Lloyd
- Microbiology Group, School of Pure and Applied Biology, University of Wales College of Cardiff, U.K
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Lloyd D, Edwards SW. Temperature‐compensated ultradian rhythms in lower eukaryotes: Periodic turnover coupled to a timer for cell division. ACTA ACUST UNITED AC 1986. [DOI: 10.1080/09291018609359923] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Woffendin C, Griffiths AJ. Changes in respiratory activity and total protein during synchronous growth of Dictyostelium discoideum. FEMS Microbiol Lett 1985. [DOI: 10.1111/j.1574-6968.1985.tb00873.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Lloyd D, Edwards SW, Williams JL, Evans J. Mitochondrial cytochromes ofAcanthamoeba castellanii: Oscillatory accumulation of haemoproteins, immunological determinants and activity during the cell cycle. FEMS Microbiol Lett 1983. [DOI: 10.1111/j.1574-6968.1983.tb00308.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Lloyd D, Edwards SW, Fry JC. Temperature-compensated oscillations in respiration and cellular protein content in synchronous cultures of Acanthamoeba castellanii. Proc Natl Acad Sci U S A 1982; 79:3785-8. [PMID: 6954521 PMCID: PMC346512 DOI: 10.1073/pnas.79.12.3785] [Citation(s) in RCA: 67] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Synchronous cultures of the soil amoeba Acanthamoeba castellanii, established by a selection procedure, show significant oscillations of respiration and total cell protein. There was little difference between the period of these oscillations, which averaged 76 min, although the five incubation temperatures used varied between 20 degrees C and 30 degrees C and the cell division time increased from 7.8 to 16 hr. The phase of these oscillations also corresponded approximately at all incubation temperatures. Similar observations made over the whole division cycle at three temperatures indicated that similar oscillations occurred, with a constant period of 65 min, although these data were too variable to show this unequivocally. Control (asynchronous) cultures show that the oscillations are not a consequence of metabolic perturbation produced by the centrifugal selection procedure. It is suggested that these temperature-compensated epigenetic oscillations serve a dual role in cell cycle and circadian timekeeping and that cell cycle time is quantized.
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Edwards SW, Evans JB, Williams JL, Lloyd D. The mitochondrial adenosine triphosphatase of Acanthamoeba castellanii. Oscillatory accumulation of enzyme activity, enzyme protein and F1-inhibitor during the cell cycle. Biochem J 1982; 202:453-8. [PMID: 6212051 PMCID: PMC1158130 DOI: 10.1042/bj2020453] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
1. The mitochondrial ATPase of Acanthamoeba castellanii accumulated discontinuously in synchronous cultures prepared by a minimally perturbing size-selection technique. 2. Enzyme activity per ml of culture doubled overall during one cell cycle time of 8 h, but oscillated to give seven maxima during this period. Similar oscillations were observed in the specific activities of ATPase and of the naturally occurring inhibitor protein. 3. These variations in enzyme activity reflected changes in amount of enzyme protein as assayed by an immunological technique. 4. Large variations in I50 values (micrograms of inhibitor/mg of protein necessary for 50% inhibition of inhibitor-sensitive activity) for inhibition of ATPase activity by seven different inhibitors of energy conservation were observed. Activity was more sensitive to inhibition by oligomycin, efrapeptin, citreoviridin and quercetin when values were highest. 5. The results are discussed in relation to the phased organization of biosynthesis and degradation of cellular components known to occur during the cell cycle of this organization.
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Lloyd D, Edwards SW, Williams JL. Oscillatory accumulation of total cellular protein in synchronous cultures ofCandida utilis. FEMS Microbiol Lett 1981. [DOI: 10.1111/j.1574-6968.1981.tb07661.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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