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Fulton JE, McCarron AM, Lund AR, Drobik-Czwarno W, Mullen A, Wolc A, Szadkowska J, Schmidt CJ, Taylor RL. The RHCE gene encodes the chicken blood system I. Genet Sel Evol 2024; 56:47. [PMID: 38898419 PMCID: PMC11188259 DOI: 10.1186/s12711-024-00911-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 05/13/2024] [Indexed: 06/21/2024] Open
Abstract
BACKGROUND There are 13 known chicken blood systems, which were originally detected by agglutination of red blood cells by specific alloantisera. The genomic region or specific gene responsible has been identified for four of these systems (A, B, D and E). We determined the identity of the gene responsible for the chicken blood system I, using DNA from multiple birds with known chicken I blood system serology, 600K and 54K single nucleotide polymorphism (SNP) data, and lowpass sequence information. RESULTS The gene responsible for the chicken I blood system was identified as RHCE, which is also one of the genes responsible for the highly polymorphic human Rh blood group locus, for which maternal/fetal antigenic differences can result in fetal hemolytic anemia with fetal mortality. We identified 17 unique RHCE haplotypes in the chicken, with six haplotypes corresponding to known I system serological alleles. We also detected deletions in the RHCE gene that encompass more than 6000 bp and that are predicted to remove its last seven exons. CONCLUSIONS RHCE is the gene responsible for the chicken I blood system. This is the fifth chicken blood system for which the responsible gene and gene variants are known. With rapid DNA-based testing now available, the impact of I blood system variation on response against disease, general immune function, and animal production can be investigated in greater detail.
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Affiliation(s)
- Janet E Fulton
- Hy-Line International, Research and Development, PO Box 310, Dallas Center, IA, USA.
| | - Amy M McCarron
- Hy-Line International, Research and Development, PO Box 310, Dallas Center, IA, USA
| | - Ashlee R Lund
- Hy-Line International, Research and Development, PO Box 310, Dallas Center, IA, USA
| | - Wioleta Drobik-Czwarno
- Department of Animal Genetics and Conservation, Institute of Animal Science, Warsaw University of Life Sciences, Warsaw, Poland
| | - Abigail Mullen
- Hy-Line International, Research and Development, PO Box 310, Dallas Center, IA, USA
| | - Anna Wolc
- Hy-Line International, Research and Development, PO Box 310, Dallas Center, IA, USA
- Department of Animal Science, Iowa State University, Ames, IA, USA
| | - Joanna Szadkowska
- Department of Animal Genetics and Conservation, Institute of Animal Science, Warsaw University of Life Sciences, Warsaw, Poland
| | - Carl J Schmidt
- Department of Animal and Food Science, University of Delaware, Newark, DE, USA
| | - Robert L Taylor
- Division of Animal and Nutritional Sciences, West Virginia University, Morgantown, WV, USA
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Flegr J, Chvátalová V, Příplatová L, Tureček P, Kodym P, Šebánková B, Kaňková Š. Cognitive Effects of Toxoplasma and CMV Infections: A Cross-Sectional Study of 557 Young Adults Considering Modulation by Sex and Rh Factor. Pathogens 2024; 13:363. [PMID: 38787216 PMCID: PMC11124290 DOI: 10.3390/pathogens13050363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 04/17/2024] [Accepted: 04/25/2024] [Indexed: 05/25/2024] Open
Abstract
One-third of humanity harbors a lifelong infection with Toxoplasma gondii, and probably about 80% are infected with human cytomegalovirus (CMV). This study aims to delineate the associations between toxoplasmosis and cognitive abilities and compare these to the associations with CMV. We evaluated the cognitive performance of 557 students, who had been examined for Toxoplasma and CMV infections, using intelligence, memory, and psychomotor tests. The results indicated cognitive impairments in seropositive individuals for both pathogens, with variations in cognitive impact related to sex and the Rh factor. Specifically, Toxoplasma infection was associated with lower IQ in men, whereas CMV was predominantly associated with worse performance by women when testing memory and reaction speeds. Analysis of the antibody concentrations indicated that certain Toxoplasma-associated cognitive detrimental effects may wane (impaired intelligence) or worsen (impaired reaction times) over time following infection. The findings imply that the cognitive impairments caused by both neurotropic pathogens are likely due to pathological changes in the brain rather than from direct manipulative action by the parasites.
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Affiliation(s)
- Jaroslav Flegr
- Laboratory of Evolutionary Biology, Department of Philosophy and History of Sciences, Faculty of Science, Charles University, Viničná 7, 128 00 Prague, Czech Republic (P.T.); (B.Š.); (Š.K.)
| | - Veronika Chvátalová
- Laboratory of Evolutionary Biology, Department of Philosophy and History of Sciences, Faculty of Science, Charles University, Viničná 7, 128 00 Prague, Czech Republic (P.T.); (B.Š.); (Š.K.)
| | - Lenka Příplatová
- Laboratory of Evolutionary Biology, Department of Philosophy and History of Sciences, Faculty of Science, Charles University, Viničná 7, 128 00 Prague, Czech Republic (P.T.); (B.Š.); (Š.K.)
| | - Petr Tureček
- Laboratory of Evolutionary Biology, Department of Philosophy and History of Sciences, Faculty of Science, Charles University, Viničná 7, 128 00 Prague, Czech Republic (P.T.); (B.Š.); (Š.K.)
| | - Petr Kodym
- National Reference Laboratory for Toxoplasmosis, Šrobárova 48, 100 42 Prague, Czech Republic
| | - Blanka Šebánková
- Laboratory of Evolutionary Biology, Department of Philosophy and History of Sciences, Faculty of Science, Charles University, Viničná 7, 128 00 Prague, Czech Republic (P.T.); (B.Š.); (Š.K.)
| | - Šárka Kaňková
- Laboratory of Evolutionary Biology, Department of Philosophy and History of Sciences, Faculty of Science, Charles University, Viničná 7, 128 00 Prague, Czech Republic (P.T.); (B.Š.); (Š.K.)
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Nayeri T, Moosazadeh M, Asl AD, Ghaffarifar F, Sarvi S, Daryani A. Toxoplasma infection and Rhesus blood group system: A systematic review and meta-analysis. PLoS One 2023; 18:e0287992. [PMID: 37406027 DOI: 10.1371/journal.pone.0287992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 06/17/2023] [Indexed: 07/07/2023] Open
Abstract
BACKGROUND Toxoplasmosis is one of the most common infections in humans and animals, which is caused by an obligate intracellular opportunistic parasite known as Toxoplasma gondii (T. gondii). Some data have shown that both Rhesus (Rh)-positive and Rh-negative individuals differ in response to biological factors, including Toxoplasma infection. Therefore, this systematic review and meta-analysis was conducted to investigate the scientific evidence regarding the possible association between the Rh blood group and Toxoplasma infection and to determine the seroprevalence of T. gondii in the Rh blood group system. METHODS The research was conducted on PubMed, ScienceDirect, ProQuest, and Google Scholar databases until January 2023. Twenty-one cross-sectional studies were included with a total of 10910 people. The data were synthesized using a random effect model with 95% confidence intervals (CIs). RESULTS The overall prevalence of T. gondii was calculated at 32.34% (CI 95%: 28.23-36.45%) and 33.35% (CI 95%: 19.73-46.96%) in Rh-positive and Rh-negative blood groups. In addition, the pooled OR for the relationship between the Rh blood group and the seroprevalence of T. gondii was 0.96 (95% CI: 0.72-1.28). CONCLUSIONS This meta-analysis showed a high prevalence of Toxoplasma infection in both Rh-negative and positive blood groups. This systematic review and meta-analysis revealed that no significant association was found between toxoplasmosis and Rh factor. Because of the limited number of studies in this field, more research is recommended to determine the exact relationship between toxoplasmosis and the Rh factor.
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Affiliation(s)
- Tooran Nayeri
- Toxoplasmosis Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mahmood Moosazadeh
- Gastrointestitional Cancer Research Center, Non-communicable Disease Institute, Mazandaran University of Medical Sciences, Sari, Iran
| | - Abdolhossein Dalimi Asl
- Department of Parasitology and Entomology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Fatemeh Ghaffarifar
- Department of Parasitology and Entomology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Shahabeddin Sarvi
- Toxoplasmosis Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Ahmad Daryani
- Toxoplasmosis Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
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Kupriyanova EV, Pronina NA, Los DA. Adapting from Low to High: An Update to CO 2-Concentrating Mechanisms of Cyanobacteria and Microalgae. PLANTS (BASEL, SWITZERLAND) 2023; 12:1569. [PMID: 37050194 PMCID: PMC10096703 DOI: 10.3390/plants12071569] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 04/03/2023] [Accepted: 04/04/2023] [Indexed: 06/19/2023]
Abstract
The intracellular accumulation of inorganic carbon (Ci) by microalgae and cyanobacteria under ambient atmospheric CO2 levels was first documented in the 80s of the 20th Century. Hence, a third variety of the CO2-concentrating mechanism (CCM), acting in aquatic photoautotrophs with the C3 photosynthetic pathway, was revealed in addition to the then-known schemes of CCM, functioning in CAM and C4 higher plants. Despite the low affinity of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) of microalgae and cyanobacteria for the CO2 substrate and low CO2/O2 specificity, CCM allows them to perform efficient CO2 fixation in the reductive pentose phosphate (RPP) cycle. CCM is based on the coordinated operation of strategically located carbonic anhydrases and CO2/HCO3- uptake systems. This cooperation enables the intracellular accumulation of HCO3-, which is then employed to generate a high concentration of CO2 molecules in the vicinity of Rubisco's active centers compensating up for the shortcomings of enzyme features. CCM functions as an add-on to the RPP cycle while also acting as an important regulatory link in the interaction of dark and light reactions of photosynthesis. This review summarizes recent advances in the study of CCM molecular and cellular organization in microalgae and cyanobacteria, as well as the fundamental principles of its functioning and regulation.
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The importance of being heterozygote: effects of RHD-genotype-sex interaction on the physical and mental health of a non-clinical population. Sci Rep 2021; 11:21960. [PMID: 34753960 PMCID: PMC8578618 DOI: 10.1038/s41598-021-00977-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 10/14/2021] [Indexed: 11/15/2022] Open
Abstract
Human populations, especially European, are polymorphic in the RHD gene. A significant fraction of their members carry no copy of the coding section of RHD gene, which results in their Rh-negative blood type. Theoretically, this polymorphism should be unstable. Carriers of the less frequent allele are penalized by reduced fertility because of the immunization of RhD-negative mothers by their RhD-positive babies, which results in hemolytic disease of the fetus and newborn in their subsequent progeny. For about 90 years, some form of balancing selection has been suspected to sustain this polymorphism. Several recent studies showed that the RhD-positive heterozygotes express higher viability than both types of homozygotes. However, the genotype of subjects in these studies was estimated only by indirect methods. Here we compared the physical and mental health of 178 women and 86 men who were directly tested for their RHD genotype. The results showed that RhD-positive homozygotic women had worse and RhD-positive homozygotic men better physical health than RhD-negative homozygotes; the difference between RhD-negative homozygotes and heterozygotes was not significant. Our results confirmed that health of RhD-positive heterozygotes and homozygotes differ. Therefore, any result of the comparison of subjects with RhD-positive and RhD-negative phenotype depends on the heterozygote-to-homozygote ratio in the RhD-positive sample. It is, therefore, crucial to analyze the effects of RHD-genotypes, not phenotypes in future studies.
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Kell DB. A protet-based, protonic charge transfer model of energy coupling in oxidative and photosynthetic phosphorylation. Adv Microb Physiol 2021; 78:1-177. [PMID: 34147184 DOI: 10.1016/bs.ampbs.2021.01.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Textbooks of biochemistry will explain that the otherwise endergonic reactions of ATP synthesis can be driven by the exergonic reactions of respiratory electron transport, and that these two half-reactions are catalyzed by protein complexes embedded in the same, closed membrane. These views are correct. The textbooks also state that, according to the chemiosmotic coupling hypothesis, a (or the) kinetically and thermodynamically competent intermediate linking the two half-reactions is the electrochemical difference of protons that is in equilibrium with that between the two bulk phases that the coupling membrane serves to separate. This gradient consists of a membrane potential term Δψ and a pH gradient term ΔpH, and is known colloquially as the protonmotive force or pmf. Artificial imposition of a pmf can drive phosphorylation, but only if the pmf exceeds some 150-170mV; to achieve in vivo rates the imposed pmf must reach 200mV. The key question then is 'does the pmf generated by electron transport exceed 200mV, or even 170mV?' The possibly surprising answer, from a great many kinds of experiment and sources of evidence, including direct measurements with microelectrodes, indicates it that it does not. Observable pH changes driven by electron transport are real, and they control various processes; however, compensating ion movements restrict the Δψ component to low values. A protet-based model, that I outline here, can account for all the necessary observations, including all of those inconsistent with chemiosmotic coupling, and provides for a variety of testable hypotheses by which it might be refined.
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Affiliation(s)
- Douglas B Kell
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative, Biology, University of Liverpool, Liverpool, United Kingdom; The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark.
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Flegr J, Toman J, Hůla M, Kaňková Š. The role of balancing selection in maintaining human RhD blood group polymorphism: A preregistered cross-sectional study. J Evol Biol 2020; 34:426-438. [PMID: 33244840 DOI: 10.1111/jeb.13745] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 11/13/2020] [Accepted: 11/18/2020] [Indexed: 01/05/2023]
Abstract
Maintenance of genetic polymorphism remains one of the big questions of evolutionary biology, which for a long time tended to be explained by balancing selection. This explanation was later criticized, but now is again accepted as an important mechanism in evolution. Human blood group systems seem affected by balancing selection especially strongly. In this preregistered study, we focused on stable coexistence of RhD-positive and RhD-negative subjects in a population. This is an evolutionary conundrum, because carriers of the less frequent negative allele suffer from lower fecundity due to haemolytic disease of the newborn affecting RhD-positive infants born to RhD-negative women. One explanation of persisting stability of RhD polymorphism points to heterozygote advantage. Over the past decade, numerous studies demonstrated that RhD-positive subjects score better than RhD-negative homozygotes in psychomotor tests and physical health-related variables. Still, evidence of better health and performance of heterozygotes is scarce and merely indirect. We compared the physical and mental health of 2,539 subjects whose RhD genotype was estimated based on their and their parents' RhD phenotype. We confirmed that RhD-negative homozygotes fare worse in terms of physical and mental health than subjects with RhD-positive phenotype and that RhD-positive heterozygotes enjoy better health than both homozygotes. For the first time, we demonstrated that RhD-positive homozygotes might suffer from worse health than RhD-negative homozygotes. Our results strongly support the hypothesis that RhD polymorphism is maintained by heterozygote advantage and that balancing selection may have played an important role in human evolution in this context and in general.
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Affiliation(s)
- Jaroslav Flegr
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Prague, Czech Republic
| | - Jan Toman
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Prague, Czech Republic
| | - Martin Hůla
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Prague, Czech Republic
| | - Šárka Kaňková
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Prague, Czech Republic.,Department of Applied Neuroscience and Neuroimaging, National Institute of Mental Health, Klecany, Czech Republic
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Flegr J, Kuba R, Kopecký R. Rhesus-minus phenotype as a predictor of sexual desire and behavior, wellbeing, mental health, and fecundity. PLoS One 2020; 15:e0236134. [PMID: 32687529 PMCID: PMC7371180 DOI: 10.1371/journal.pone.0236134] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 06/29/2020] [Indexed: 12/25/2022] Open
Abstract
Background Since its discovery in the 1930s, the effects of Rh phenotype on human health and wellbeing, with the exception of the effects of Rh-negativity of a mother on the risk of hemolytic anemia of Rh-positive children, has only rarely been studied. In the last few years, however, several studies have shown that Rh-negative subjects have worse health and performance in certain tests than their Rh-positive peers. Nothing is known about the effect of Rh phenotype on the quality of life of subjects as measured by a standard instrument. Methods We hereby analyzed the data of 1768 male (24% Rh-negative) and 3759 female participants (23% Rh-negative) of an anonymous internet study using the partial Kendall test with the age and the population of the hometown of subjects controlled. Results The results showed that the Rh-negative women, but not men, scored worse in wellbeing measured with the WHO-BREFF. The Rh-negative men scored worse in mental health-related variables and in their reported economic situation and the Rh-negative women scored better in physical health-related variables. Both the Rh-negative men and women reported higher sexual activity than their Rh-positive peers. Conclusions The effects of the Rh phenotype were significant after the correction for multiple tests. However, they were usually weaker and less numerous than those of smoking, consuming alcohol, and high body mass index, which were used as a sort of internal control.
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Affiliation(s)
- Jaroslav Flegr
- Department of Applied Neurosciences and Brain Imagination, National Institute of Mental Health, Klecany, Czech Republic
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Prague, Czech Republic
- * E-mail:
| | - Radim Kuba
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Prague, Czech Republic
- Department of Teaching and Didactics of Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Robin Kopecký
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Prague, Czech Republic
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Kaňková Š, Flegr J, Toman J, Calda P. Maternal RhD heterozygous genotype is associated with male biased secondary sex ratio. Early Hum Dev 2020; 140:104864. [PMID: 31500940 DOI: 10.1016/j.earlhumdev.2019.104864] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Previous studies suggest that RhD positive heterozygotes express better health status than RhD positive homozygotes and especially RhD negative subjects. This also applies to pregnant women. According to the Trivers-Willard hypothesis, women in better physical condition should have more sons. AIM To test the hypothesis that RhD positive heterozygous mothers have a male-skewed sex ratio. STUDY DESIGN Cross-sectional study. The data was analysed using Chi-Square test for all women, separately for RhD positive and RhD negative women, and separately for primiparous and multiparous women. The effects of maternal weight as a continuous predictor and the RhD phenotype of newborn as a categorical predictor of newborn sex were evaluated by the generalized linear model (GLZ) separately for RhD positive and RhD negative women using binomial distribution and logit link function. OUTCOME MEASURES Clinical records comprised maternal weight before pregnancy, number of previous deliveries, sex of the newborn, maternal RhD phenotype, and RhD phenotype of the newborn. SUBJECTS We analysed data from 5655 women who gave birth between 2008 and 2012 in General University Hospital in Prague. RESULTS Secondary sex ratio was significantly higher (P = 0.028) in RhD positive mothers who had RhD negative newborns, i.e., in heterozygotes (SR = 1.23), than in RhD positive mothers who had RhD positive newborns, i.e., in a mixed population of heterozygotes and homozygotes (SR = 1.00), especially in primiparous women (P = 0.013; SR = 1.37 and 0.99 resp.). CONCLUSION The sex ratio at birth was significantly higher in RhD positive mothers who had RhD negative newborns than in RhD positive mothers who had RhD positive newborns.
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Affiliation(s)
- Šárka Kaňková
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Prague CZ-128 44, Prague 2, Czech Republic.
| | - Jaroslav Flegr
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Prague CZ-128 44, Prague 2, Czech Republic
| | - Jan Toman
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Prague CZ-128 44, Prague 2, Czech Republic
| | - Pavel Calda
- Department of Obstetrics and Gynaecology, General University Hospital and First Faculty of Medicine, Charles University, Prague CZ-128 08, Prague 2, Czech Republic
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Durant AC, Donini A. Development of Aedes aegypti (Diptera: Culicidae) mosquito larvae in high ammonia sewage in septic tanks causes alterations in ammonia excretion, ammonia transporter expression, and osmoregulation. Sci Rep 2019; 9:19028. [PMID: 31836747 PMCID: PMC6911005 DOI: 10.1038/s41598-019-54413-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 11/12/2019] [Indexed: 12/18/2022] Open
Abstract
Larvae of the disease vector mosquito, Aedes aegypti (L.) readily develop in ammonia rich sewage in the British Virgin Islands. To understand how the larvae survive in ammonia levels that are lethal to most animals, an examination of ammonia excretory physiology in larvae collected from septic-water and freshwater was carried out. A. aegypti larvae were found to be remarkably plastic in dealing with high external ammonia through the modulation of NH4+ excretion at the anal papillae, measured using the scanning ion-selective electrode technique (SIET), and NH4+ secretion in the primary urine by the Malpighian tubules when developing in septicwater. Ammonia transporters, Amt and Rh proteins, are expressed in ionoregulatory and excretory organs, with increases in Rh protein, Na+-K+-ATPase, and V-type-H+-ATPase expression observed in the Malpighian tubules, hindgut, and anal papillae in septic-water larvae. A comparative approach using laboratory A. aegypti larvae reared in high ammonia septic-water revealed similar responses to collected A. aegypti with regard to altered ammonia secretion and hemolymph ion composition. Results suggest that the observed alterations in excretory physiology of larvae developing in septic-water is a consequence of the high ammonia levels and that A. aegypti larvae may rely on ammonia transporting proteins coupled to active transport to survive in septic-water.
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Affiliation(s)
- Andrea C Durant
- Department of Biology, York University, Toronto, Ontario, Canada.
| | - Andrew Donini
- Department of Biology, York University, Toronto, Ontario, Canada
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Maeda K, Westerhoff HV, Kurata H, Boogerd FC. Ranking network mechanisms by how they fit diverse experiments and deciding on E. coli's ammonium transport and assimilation network. NPJ Syst Biol Appl 2019; 5:14. [PMID: 30993002 PMCID: PMC6461619 DOI: 10.1038/s41540-019-0091-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 03/12/2019] [Indexed: 11/17/2022] Open
Abstract
The complex ammonium transport and assimilation network of E. coli involves the ammonium transporter AmtB, the regulatory proteins GlnK and GlnB, and the central N-assimilating enzymes together with their highly complex interactions. The engineering and modelling of such a complex network seem impossible because functioning depends critically on a gamut of data known at patchy accuracy. We developed a way out of this predicament, which employs: (i) a constrained optimization-based technology for the simultaneous fitting of models to heterogeneous experimental data sets gathered through diverse experimental set-ups, (ii) a 'rubber band method' to deal with different degrees of uncertainty, both in experimentally determined or estimated parameter values and in measured transient or steady-state variables (training data sets), (iii) integration of human expertise to decide on accuracies of both parameters and variables, (iv) massive computation employing a fast algorithm and a supercomputer, (v) an objective way of quantifying the plausibility of models, which makes it possible to decide which model is the best and how much better that model is than the others. We applied the new technology to the ammonium transport and assimilation network, integrating recent and older data of various accuracies, from different expert laboratories. The kinetic model objectively ranked best, has E. coli's AmtB as an active transporter of ammonia to be assimilated with GlnK minimizing the futile cycling that is an inevitable consequence of intracellular ammonium accumulation. It is 130 times better than a model with facilitated passive transport of ammonia.
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Affiliation(s)
- Kazuhiro Maeda
- Frontier Research Academy for Young Researchers, Kyushu Institute of Technology, Kitakyushu, Fukuoka, Japan
- Department of Bioscience and Bioinformatics, Kyushu Institute of Technology, Iizuka, Fukuoka Japan
| | - Hans V. Westerhoff
- Department of Molecular Cell Biology, Faculty of Science, VU University Amsterdam, O|2 building, Amsterdam, Netherlands
- Manchester Centre for Integrative Systems Biology, Manchester Interdisciplinary Biocentre, School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester, UK
- Synthetic Systems Biology and Nuclear Organization, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Hiroyuki Kurata
- Department of Bioscience and Bioinformatics, Kyushu Institute of Technology, Iizuka, Fukuoka Japan
- Biomedical Informatics R&D Center, Kyushu Institute of Technology, Iizuka, Fukuoka Japan
| | - Fred C. Boogerd
- Department of Molecular Cell Biology, Faculty of Science, VU University Amsterdam, O|2 building, Amsterdam, Netherlands
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Brauner CJ, Shartau RB, Damsgaard C, Esbaugh AJ, Wilson RW, Grosell M. Acid-base physiology and CO2 homeostasis: Regulation and compensation in response to elevated environmental CO2. FISH PHYSIOLOGY 2019. [DOI: 10.1016/bs.fp.2019.08.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Durant AC, Donini A. Evidence that Rh proteins in the anal papillae of the freshwater mosquito Aedes aegypti are involved in the regulation of acid-base balance in elevated salt and ammonia environments. ACTA ACUST UNITED AC 2018; 221:jeb.186866. [PMID: 30305376 DOI: 10.1242/jeb.186866] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 10/04/2018] [Indexed: 12/13/2022]
Abstract
Aedes aegypti commonly inhabit ammonia-rich sewage effluents in tropical regions of the world where the adults are responsible for the spread of disease. Studies have shown the importance of the anal papillae of A. aegypti in ion uptake and ammonia excretion. The anal papillae express ammonia transporters and Rhesus (Rh) proteins which are involved in ammonia excretion and studies have primarily focused on understanding these mechanisms in freshwater. In this study, effects of rearing larvae in salt (5 mmol l-1 NaCl) or ammonia (5 mmol l-1 NH4Cl) on physiological endpoints of ammonia and ion regulation were assessed. In anal papillae of NaCl-reared larvae, Rh protein expression increased, NHE3 transcript abundance decreased and NH4 + excretion increased, and this coincided with decreased hemolymph [NH4 +] and pH. We propose that under these conditions, larvae excrete more NH4 + through Rh proteins as a means of eliminating acid from the hemolymph. In anal papillae of NH4Cl-reared larvae, expression of an apical ammonia transporter and the Rh proteins decreased, the activities of NKA and VA decreased and increased, respectively, and this coincided with hemolymph acidification. The results present evidence for a role of Rh proteins in acid-base balance in response to elevated levels of salt, whereby ammonia is excreted as an acid equivalent.
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Affiliation(s)
- Andrea C Durant
- Department of Biology, York University, Toronto, ON, Canada M3J 1P3
| | - Andrew Donini
- Department of Biology, York University, Toronto, ON, Canada M3J 1P3
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14
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Durant AC, Donini A. Ammonia Excretion in an Osmoregulatory Syncytium Is Facilitated by AeAmt2, a Novel Ammonia Transporter in Aedes aegypti Larvae. Front Physiol 2018; 9:339. [PMID: 29695971 PMCID: PMC5905399 DOI: 10.3389/fphys.2018.00339] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 03/20/2018] [Indexed: 02/03/2023] Open
Abstract
The larvae of the mosquito Aedes aegypti inhabit ammonia rich septic tanks in tropical regions of the world that make extensive use of these systems, explaining the prevalence of disease during dry seasons. Since ammonia (NH3/NH4+) is toxic to animals, an understanding of the physiological mechanisms of ammonia excretion permitting the survival of A. aegypti larvae in high ammonia environments is important. We have characterized a novel ammonia transporter, AeAmt2, belonging to the Amt/MEP/Rh family of ammonia transporters. Based on the amino acid sequence, the predicted topology of AeAmt2 consists of 11 transmembrane helices with an extracellular N-terminus and a cytoplasmic C-terminus region. Alignment of the predicted AeAmt2 amino acid sequence with other Amt/MEP proteins from plants, bacteria, and yeast highlights the presence of conserved residues characteristic of ammonia conducting channels in this protein. AeAmt2 is expressed in the ionoregulatory anal papillae of A. aegypti larvae where it is localized to the apical membrane of the epithelium. dsRNA-mediated knockdown of AeAmt2 results in a significant decrease in NH4+ efflux from the anal papillae, suggesting a key role in facilitating ammonia excretion. The effect of high environmental ammonia (HEA) on expression of AeAmt2, along with previously characterized AeAmt1, AeRh50-1, and AeRh50-2 in the anal papillae was investigated. We show that changes in expression of ammonia transporters occur in response to acute and chronic exposure to HEA, which reflects the importance of these transporters in the physiology of life in high ammonia habitats.
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Affiliation(s)
| | - Andrew Donini
- Department of Biology, York University, Toronto, ON, Canada
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15
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Groszmann M, Osborn HL, Evans JR. Carbon dioxide and water transport through plant aquaporins. PLANT, CELL & ENVIRONMENT 2017; 40:938-961. [PMID: 27739588 DOI: 10.1111/pce.12844] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 09/01/2016] [Accepted: 09/22/2016] [Indexed: 05/25/2023]
Abstract
Aquaporins are channel proteins that function to increase the permeability of biological membranes. In plants, aquaporins are encoded by multigene families that have undergone substantial diversification in land plants. The plasma membrane intrinsic proteins (PIPs) subfamily of aquaporins is of particular interest given their potential to improve plant water relations and photosynthesis. Flowering plants have between 7 and 28 PIP genes. Their expression varies with tissue and cell type, through development and in response to a variety of factors, contributing to the dynamic and tissue specific control of permeability. There are a growing number of PIPs shown to act as water channels, but those altering membrane permeability to CO2 are more limited. The structural basis for selective substrate specificities has not yet been resolved, although a few key amino acid positions have been identified. Several regions important for dimerization, gating and trafficking are also known. PIP aquaporins assemble as tetramers and their properties depend on the monomeric composition. PIPs control water flux into and out of veins and stomatal guard cells and also increase membrane permeability to CO2 in mesophyll and stomatal guard cells. The latter increases the effectiveness of Rubisco and can potentially influence transpiration efficiency.
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Affiliation(s)
- Michael Groszmann
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Division of Plant Sciences, Research School of Biology, The Australian National University, Acton, ACT, 2601, Australia
| | - Hannah L Osborn
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Division of Plant Sciences, Research School of Biology, The Australian National University, Acton, ACT, 2601, Australia
| | - John R Evans
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Division of Plant Sciences, Research School of Biology, The Australian National University, Acton, ACT, 2601, Australia
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16
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Durant AC, Chasiotis H, Misyura L, Donini A. Aedes aegypti Rhesus glycoproteins contribute to ammonia excretion by larval anal papillae. ACTA ACUST UNITED AC 2016; 220:588-596. [PMID: 27885043 DOI: 10.1242/jeb.151084] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 11/21/2016] [Indexed: 02/06/2023]
Abstract
In larval Aedes aegypti, transcripts of the Rhesus-like glycoproteins AeRh50-1 and AeRh50-2 have been detected in the anal papillae, sites of ammonia (NH3/NH4+) excretion; however, these putative ammonia transporters have not been previously localized or functionally characterized. In this study, we show that the AeRh50s co-immunolocalize with apical V-type H+-ATPase as well as with basal Na+/K+-ATPase in the epithelium of anal papillae. The double-stranded RNA-mediated knockdown of AeRh50-1 and AeRh50-2 resulted in a significant reduction in AeRh50 protein abundance in the anal papillae, and this was coupled to decreased ammonia excretion. The knockdown of AeRh50-1 resulted in decreased hemolymph [NH4+] and pH whereas knockdown of AeRh50-2 had no effect on these parameters. We conclude that the AeRh50s are important contributors to ammonia excretion at the anal papillae of larval A. aegypti, which may be the basis for their ability to inhabit areas with high ammonia levels.
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Affiliation(s)
- Andrea C Durant
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3
| | - Helen Chasiotis
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3
| | - Lidiya Misyura
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3
| | - Andrew Donini
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3
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17
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Thiel D, Hugenschütt M, Meyer H, Paululat A, Quijada-Rodriguez AR, Purschke G, Weihrauch D. Ammonia excretion in the marine polychaete Eurythoe complanata (Annelida). ACTA ACUST UNITED AC 2016; 220:425-436. [PMID: 27852754 DOI: 10.1242/jeb.145615] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 11/11/2016] [Indexed: 12/31/2022]
Abstract
Ammonia is a toxic waste product from protein metabolism and needs to be either converted into less toxic molecules or, in the case of fish and aquatic invertebrates, excreted directly as is. In contrast to fish, very little is known regarding the ammonia excretion mechanism and the participating excretory organs in marine invertebrates. In the current study, ammonia excretion in the marine burrowing polychaete Eurythoe complanata was investigated. As a potential site for excretion, the 100-200 µm long, 30-50 µm wide and up to 25 µm thick dentrically branched, well ventilated and vascularized branchiae (gills) were identified. In comparison to the main body, the branchiae showed considerably higher mRNA expression levels of Na+/K+-ATPase, V-type H+-ATPase, cytoplasmic carbonic anhydrase (CA-2), a Rhesus-like protein, and three different ammonia transporters (AMTs). Experiments on the intact organism revealed that ammonia excretion did not occur via apical ammonia trapping, but was regulated by a basolateral localized V-type H+-ATPase, carbonic anhydrase and intracellular cAMP levels. Interestingly, the V-type H+-ATPase seems to play a role in ammonia retention. A 1 week exposure to 1 mmol l-1 NH4Cl (HEA) did not cause a change in ammonia excretion rates, while the three branchial expressed AMTs showed a tendency to be down-regulated. This indicates a shift of function in the branchial ammonia excretion processes under these conditions.
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Affiliation(s)
- Daniel Thiel
- University of Osnabrück, Fachbereich Biologie, Department of Zoology, Osnabrück 49069, Germany
| | - Maja Hugenschütt
- University of Osnabrück, Fachbereich Biologie, Department of Zoology, Osnabrück 49069, Germany
| | - Heiko Meyer
- University of Osnabrück, Fachbereich Biologie, Department of Zoology, Osnabrück 49069, Germany
| | - Achim Paululat
- University of Osnabrück, Fachbereich Biologie, Department of Zoology, Osnabrück 49069, Germany
| | | | - Günter Purschke
- University of Osnabrück, Fachbereich Biologie, Department of Zoology, Osnabrück 49069, Germany
| | - Dirk Weihrauch
- University of Manitoba, Department of Biological Sciences, Winnipeg, Manitoba, Canada
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18
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Adlimoghaddam A, O'Donnell MJ, Kormish J, Banh S, Treberg JR, Merz D, Weihrauch D. Ammonia excretion in Caenorhabditis elegans: Physiological and molecular characterization of the rhr-2 knock-out mutant. Comp Biochem Physiol A Mol Integr Physiol 2016; 195:46-54. [DOI: 10.1016/j.cbpa.2016.02.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 02/04/2016] [Accepted: 02/07/2016] [Indexed: 12/16/2022]
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19
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McDonald TR, Ward JM. Evolution of Electrogenic Ammonium Transporters (AMTs). FRONTIERS IN PLANT SCIENCE 2016; 7:352. [PMID: 27066024 PMCID: PMC4814505 DOI: 10.3389/fpls.2016.00352] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2015] [Accepted: 03/07/2016] [Indexed: 05/05/2023]
Abstract
The ammonium transporter gene family consists of three main clades, AMT, MEP, and Rh. The evolutionary history of the AMT/MEP/Rh gene family is characterized by multiple horizontal gene transfer events, gene family expansion and contraction, and gene loss; thus the gene tree for this family of transporters is unlike the organismal tree. The genomes of angiosperms contain genes for both electrogenic and electroneutral ammonium transporters, but it is not clear how far back in the land plant lineage electrogenic ammonium transporters occur. Here, we place Marchantia polymorpha ammonium transporters in the AMT/MEP/Rh phylogeny and we show that AMTs from the liverwort M. polymorpha are electrogenic. This information suggests that electrogenic ammonium transport evolved at least as early as the divergence of bryophytes in the land plant lineage.
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Affiliation(s)
| | - John M. Ward
- Department of Plant Biology, University of MinnesotaSt. Paul, MN, USA
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20
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Modulating intracellular acidification by regulating the incubation time of proton caged compounds. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2016; 45:565-71. [DOI: 10.1007/s00249-016-1122-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 02/05/2016] [Accepted: 02/20/2016] [Indexed: 10/22/2022]
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21
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Chasiotis H, Ionescu A, Misyura L, Bui P, Fazio K, Wang J, Patrick M, Weihrauch D, Donini A. An animal homolog of plant Mep/Amt transporters promotes ammonia excretion by the anal papillae of the disease vector mosquito Aedes aegypti. ACTA ACUST UNITED AC 2016; 219:1346-55. [PMID: 26944496 DOI: 10.1242/jeb.134494] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 02/22/2016] [Indexed: 12/16/2022]
Abstract
The transcripts of three putative ammonia (NH3/NH4 (+)) transporters, Rhesus-like glycoproteins AeRh50-1, AeRh50-2 and Amt/Mep-like AeAmt1 were detected in the anal papillae of larval Aedes aegypti Quantitative PCR studies revealed 12-fold higher transcript levels of AeAmt1 in anal papillae relative to AeRh50-1, and levels of AeRh50-2 were even lower. Immunoblotting revealed AeAmt1 in anal papillae as a pre-protein with putative monomeric and trimeric forms. AeAmt1 was immunolocalized to the basal side of the anal papillae epithelium where it co-localized with Na(+)/K(+)-ATPase. Ammonium concentration gradients were measured adjacent to anal papillae using the scanning ion-selective electrode technique (SIET) and used to calculate ammonia efflux by the anal papillae. dsRNA-mediated reductions in AeAmt1 decreased ammonia efflux at larval anal papillae and significantly increased ammonia levels in hemolymph, indicating a principal role for AeAmt1 in ammonia excretion. Pharmacological characterization of ammonia transport mechanisms in the anal papillae suggests that, in addition to AeAmt1, the ionomotive pumps V-type H(+)-ATPase and Na(+)/K(+)-ATPase as well as NHE3 are involved in ammonia excretion at the anal papillae.
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Affiliation(s)
- Helen Chasiotis
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3
| | - Adrian Ionescu
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3
| | - Lidiya Misyura
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3
| | - Phuong Bui
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3
| | - Kimberly Fazio
- Department of Biology, University of San Diego, 5998 Alcala Park, San Diego, CA 92110, USA
| | - Jason Wang
- Department of Biology, University of San Diego, 5998 Alcala Park, San Diego, CA 92110, USA
| | - Marjorie Patrick
- Department of Biology, University of San Diego, 5998 Alcala Park, San Diego, CA 92110, USA
| | - Dirk Weihrauch
- Department of Biological Sciences, University of Manitoba, 50 Sifton Road, Winnipeg, Manitoba, Canada R3T 2N2
| | - Andrew Donini
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3
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22
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Flegr J. Heterozygote Advantage Probably Maintains Rhesus Factor Blood Group Polymorphism: Ecological Regression Study. PLoS One 2016; 11:e0147955. [PMID: 26811928 PMCID: PMC4728066 DOI: 10.1371/journal.pone.0147955] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 01/11/2016] [Indexed: 11/18/2022] Open
Abstract
Rhesus factor polymorphism has been an evolutionary enigma since its discovery in 1939. Carriers of the rarer allele should be eliminated by selection against Rhesus positive children born to Rhesus negative mothers. Here I used an ecologic regression study to test the hypothesis that Rhesus factor polymorphism is stabilized by heterozygote advantage. The study was performed in 65 countries for which the frequencies of RhD phenotypes and specific disease burden data were available. I performed multiple multivariate covariance analysis with five potential confounding variables: GDP, latitude (distance from the equator), humidity, medical care expenditure per capita and frequencies of smokers. The results showed that the burden associated with many diseases correlated with the frequencies of particular Rhesus genotypes in a country and that the direction of the relation was nearly always the opposite for the frequency of Rhesus negative homozygotes and that of Rhesus positive heterozygotes. On the population level, a Rhesus-negativity-associated burden could be compensated for by the heterozygote advantage, but for Rhesus negative subjects this burden represents a serious problem.
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Affiliation(s)
- Jaroslav Flegr
- Division of Biology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
- * E-mail:
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23
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Flegr J, Hoffmann R, Dammann M. Worse Health Status and Higher Incidence of Health Disorders in Rhesus Negative Subjects. PLoS One 2015; 10:e0141362. [PMID: 26495842 PMCID: PMC4619848 DOI: 10.1371/journal.pone.0141362] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2015] [Accepted: 10/06/2015] [Indexed: 11/19/2022] Open
Abstract
Rhesus-positive and Rhesus-negative persons differ in the presence-absence of highly immunogenic RhD protein on the erythrocyte membrane. The biological function of the RhD molecule is unknown. Its structure suggests that the molecular complex with RhD protein transports NH3 or CO2 molecules across the erythrocyte cell membrane. Some data indicate that RhD positive and RhD negative subjects differ in their tolerance to certain biological factors, including, Toxoplasma infection, aging and fatique. Present cross sectional study performed on 3,130 subjects) showed that Rhesus negative subjects differed in many indices of their health status, including incidences of many disorders. Rhesus negative subjects reported to have more frequent allergic, digestive, heart, hematological, immunity, mental health, and neurological problems. On the population level, a Rhesus-negativity-associated burden could be compensated for, for example, by the heterozygote advantage, but for Rhesus negative subjects this burden represents a serious problem.
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Affiliation(s)
- Jaroslav Flegr
- Division of Biology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
- * E-mail:
| | - Rudolf Hoffmann
- Department of Hematology, Na Homolce Hospital, Prague, Czech Republic
| | - Mike Dammann
- Division of Biology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
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24
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Wang Y, Stessman DJ, Spalding MH. The CO2 concentrating mechanism and photosynthetic carbon assimilation in limiting CO2 : how Chlamydomonas works against the gradient. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 82:429-448. [PMID: 25765072 DOI: 10.1111/tpj.12829] [Citation(s) in RCA: 156] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 03/08/2015] [Accepted: 03/11/2015] [Indexed: 05/04/2023]
Abstract
The CO2 concentrating mechanism (CCM) represents an effective strategy for carbon acquisition that enables microalgae to survive and proliferate when the CO2 concentration limits photosynthesis. The CCM improves photosynthetic performance by raising the CO2 concentration at the site of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), simultaneously enhancing carbon fixation and suppressing photorespiration. Active inorganic carbon (Ci) uptake, Rubisco sequestration and interconversion between different Ci species catalyzed by carbonic anhydrases (CAs) are key components in the CCM, and an array of molecular regulatory elements is present to facilitate the sensing of CO2 availability, to regulate the expression of the CCM and to coordinate interplay between photosynthetic carbon metabolism and other metabolic processes in response to limiting CO2 conditions. This review intends to integrate our current understanding of the eukaryotic algal CCM and its interaction with carbon assimilation, based largely on Chlamydomonas as a model, and to illustrate how Chlamydomonas acclimates to limiting CO2 conditions and how its CCM is regulated.
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Affiliation(s)
- Yingjun Wang
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, Iowa, USA
| | - Dan J Stessman
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, Iowa, USA
| | - Martin H Spalding
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, Iowa, USA
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25
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Nawata CM, Walsh PJ, Wood CM. Nitrogen metabolism, acid-base regulation, and molecular responses to ammonia and acid infusions in the spiny dogfish shark (Squalus acanthias). J Comp Physiol B 2015; 185:511-25. [PMID: 25794843 DOI: 10.1007/s00360-015-0898-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Revised: 01/18/2015] [Accepted: 03/10/2015] [Indexed: 11/25/2022]
Abstract
Although they are ureotelic, marine elasmobranchs express Rh glycoproteins, putative ammonia channels. To address questions raised by a recent study on high environmental ammonia (HEA) exposure, dogfish were intravascularly infused for 24 h at 3 ml kg(-1) h(-1) with isosmotic NaCl (500 mmol l(-1), control), NH4HCO3 (500 mmol l(-1)), NH4Cl (500 mmol l(-1)), or HCl (as 125 mmol l(-1) HCl + 375 mmol l(-1) NaCl). While NaCl had no effect on arterial acid-base status, NH4HCO3 caused mild alkalosis, NH4Cl caused strong acidosis, and HCl caused lesser acidosis, all predominantly metabolic in nature. Total plasma ammonia (T(Amm)) and excretion rates of ammonia (J(Amm)) and urea-N (J(Urea-N)) were unaffected by NaCl or HCl. However, despite equal loading rates, plasma T(Amm) increased to a greater extent with NH4Cl, while J(Amm) increased to a greater extent with NH4HCO3 due to much greater increases in blood-to-water PNH3 gradients. As with HEA, both treatments caused large (90%) elevations of J(Urea-N), indicating that urea-N synthesis by the ornithine-urea cycle (OUC) is driven primarily by ammonia rather than HCO3(-). Branchial mRNA expressions of Rhbg and Rhp2 were unaffected by NH4HCO3 or NH4Cl, but v-type H(+)-ATPase was down-regulated by both treatments, and Rhbg and Na(+)/H(+) exchanger NHE2 were up-regulated by HCl. In the kidney, Rhbg was unresponsive to all treatments, but Rhp2 was up-regulated by HCl, and the urea transporter UT was up-regulated by HCl and NH4Cl. These responses are discussed in the context of current ideas about branchial, renal, and OUC function in this nitrogen-limited predator.
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Affiliation(s)
- C Michele Nawata
- Bamfield Marine Sciences Centre, 100 Pachena Road, Bamfield, BC, V0R 1B0, Canada,
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26
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Nakhoul NL, Lee Hamm L. The challenge of determining the role of Rh glycoproteins in transport of NH3and NH4+. ACTA ACUST UNITED AC 2014. [DOI: 10.1002/wmts.105] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Nazih L. Nakhoul
- Department of Physiology; Tulane University Medical School; New Orleans LA USA
- Department of Medicine, Section of Nephrology; Tulane University Medical School; New Orleans LA USA
| | - L. Lee Hamm
- Department of Medicine, Section of Nephrology; Tulane University Medical School; New Orleans LA USA
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27
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28
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Karmakar T, Periyasamy G, Balasubramanian S. CO2 migration pathways in oxalate decarboxylase and clues about its active site. J Phys Chem B 2013; 117:12451-60. [PMID: 24053484 DOI: 10.1021/jp4074834] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Oxalate decarboxylase catalyzes the decarboxylation of oxalate to formate and CO2 in the presence of molecular oxygen. This enzyme has two domains, each containing a Mn(II) ion coordinated with three histidine residues. The specific domain in which the decarboxylation process takes place is still a matter of investigation. Herein, the transport of the product, i.e., CO2, from the reaction center to the surface of the enzyme is studied using atomistic molecular dynamics simulations. The specific pathway for the migration of the molecule as well as its microscopic interactions with the amino acid residues lining the path is delineated. Further, the transport of CO2 is shown to occur in a facile manner from only domain I and not from domain II, indicating that the former is likely to be the active site of the enzyme.
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Affiliation(s)
- Tarak Karmakar
- Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research , Bangalore 560 064, India
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29
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Cummins EP, Selfridge AC, Sporn PH, Sznajder JI, Taylor CT. Carbon dioxide-sensing in organisms and its implications for human disease. Cell Mol Life Sci 2013; 71:831-45. [PMID: 24045706 DOI: 10.1007/s00018-013-1470-6] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 08/22/2013] [Accepted: 08/30/2013] [Indexed: 12/29/2022]
Abstract
The capacity of organisms to sense changes in the levels of internal and external gases and to respond accordingly is central to a range of physiologic and pathophysiologic processes. Carbon dioxide, a primary product of oxidative metabolism is one such gas that can be sensed by both prokaryotic and eukaryotic cells and in response to altered levels, elicit the activation of multiple adaptive pathways. The outcomes of activating CO2-sensitive pathways in various species include increased virulence of fungal and bacterial pathogens, prey-seeking behavior in insects as well as taste perception, lung function, and the control of immunity in mammals. In this review, we discuss what is known about the mechanisms underpinning CO2 sensing across a range of species and consider the implications of this for physiology, disease progression, and the possibility of developing new therapeutics for inflammatory and infectious disease.
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Affiliation(s)
- Eoin P Cummins
- School of Medicine and Medical Science, UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
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30
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Qin X, Boron WF. Mutation of a single amino acid converts the human water channel aquaporin 5 into an anion channel. Am J Physiol Cell Physiol 2013; 305:C663-72. [DOI: 10.1152/ajpcell.00129.2013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Aquaporin 6 (AQP6) is unique among mammalian AQPs in being an anion channel with negligible water permeability. However, the point mutation Asn60Gly converts AQP6 from an anion channel into a water channel. In the present study of human AQP5, we mutated Leu51 (corresponding to residue 61 in AQP6), the side chain of which faces the central pore. We evaluated function in Xenopus oocytes by two-electrode voltage clamp, video measurements of osmotic H2O permeability ( Pf), microelectrode measurements of surface pH (pHS) to assess CO2 permeability, and surface biotinylation. We found that AQP5-L51R does not exhibit the H2O or CO2 permeability of the wild-type protein but instead has a novel p-chloromercuribenzene sulfonate (pCMBS)-sensitive current. The double mutant AQP5-L51R/C182S renders the conductance insensitive to pCMBS, demonstrating that the current is intrinsic to AQP5. AQP5-L51R has the anion permeability sequence I− > NO3− ≅ NO2− > Br− > Cl− > HCO3− > gluconate. Of the other L51 mutants, L51T (polar uncharged) and L51V (nonpolar) retain H2O and CO2 permeability and do not exhibit anion conductance. L51D and L51E (negatively charged) have no H2O or CO2 permeability. L51K (positively charged) has an intermediate H2O and CO2 permeability and anion conductance. L51H is unusual in having a relatively low CO2 permeability and anion conductance, but a moderate Pf. Thus, positively charged mutations of L51 can convert AQP5 from a H2O/CO2 channel into an anion channel. However, the paradoxical effect of L51H is consistent with the hypothesis that CO2, in part, takes a pathway different from H2O through AQP5.
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Affiliation(s)
- Xue Qin
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Walter F. Boron
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio
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Characteristics of mammalian Rh glycoproteins (SLC42 transporters) and their role in acid-base transport. Mol Aspects Med 2013; 34:629-37. [PMID: 23506896 DOI: 10.1016/j.mam.2012.05.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 04/16/2012] [Indexed: 01/06/2023]
Abstract
The mammalian Rh glycoproteins belong to the solute transporter family SLC42 and include RhAG, present in red blood cells, and two non-erythroid members RhBG and RhCG that are expressed in various tissues, including kidney, liver, skin and the GI tract. The Rh proteins in the red blood cell form an "Rh complex" made up of one D-subunit, one CE-subunit and two RhAG subunits. The Rh complex has a well-known antigenic effect but also contributes to the stability of the red cell membrane. RhBG and RhCG are related to the NH4(+) transporters of the yeast and bacteria but their exact function is yet to be determined. This review describes the expression and molecular properties of these membrane proteins and their potential role as NH3/NH4(+) and CO2 transporters. The likelihood that these proteins transport gases such as CO2 or NH3 is novel and significant. The review also describes the physiological importance of these proteins and their relevance to human disease.
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Flegr J, Preiss M, Klose J. Toxoplasmosis-associated difference in intelligence and personality in men depends on their Rhesus blood group but not ABO blood group. PLoS One 2013; 8:e61272. [PMID: 23593448 PMCID: PMC3622667 DOI: 10.1371/journal.pone.0061272] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Accepted: 03/07/2013] [Indexed: 01/03/2023] Open
Abstract
Background The parasite Toxoplasma gondii influences the behaviour of infected animals and probably also personality of infected humans. Subjects with a Rhesus-positive blood group are protected against certain behavioural effects associated with Toxoplasma infection, including the deterioration of reaction times and personality factor shift. Methodology/Principal Findings Here, we searched for differences in the toxoplasmosis-associated effects between RhD-positive and RhD-negative subjects by testing 502 soldiers with two personality tests and two intelligence tests. The infected subjects expressed lower levels of all potentially pathognomic factors measured with the N-70 questionnaire and in neurasthenia measured with NEO-PI-R. The RhD-positive, Toxoplasma-infected subjects expressed lower while RhD-negative, Toxoplasma-infected subjects expressed higher intelligence than their Toxoplasma-free peers. The observed Toxoplasma-associated differences were always larger in RhD-negative than in RhD-positive subjects. Conclusions RhD phenotype plays an important role in the strength and direction of association between latent toxoplasmosis and not only psychomotor performance, but also personality and intelligence.
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Affiliation(s)
- Jaroslav Flegr
- Department of Biology, Faculty of Science, Charles University in Prague, Prague, Czech Republic.
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High-throughput genome sequencing of lichenizing fungi to assess gene loss in the ammonium transporter/ammonia permease gene family. BMC Genomics 2013; 14:225. [PMID: 23557360 PMCID: PMC3663718 DOI: 10.1186/1471-2164-14-225] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Accepted: 02/13/2013] [Indexed: 11/20/2022] Open
Abstract
Background Horizontal gene transfer has shaped the evolution of the ammonium transporter/ammonia permease gene family. Horizontal transfers of ammonium transporter/ammonia permease genes into the fungi include one transfer from archaea to the filamentous ascomycetes associated with the adaptive radiation of the leotiomyceta. The horizontally transferred gene has subsequently been lost in most of the group but has been selectively retained in lichenizing fungi. However, some groups of lichens appear to have secondarily lost the archaeal ammonium transporter. Definitive assessment of gene loss can only be made via whole genome sequencing. Results Ammonium transporter/ammonia permease gene sequences were recovered from the assembled genomes of eight lichenizing fungi in key clades including the Caliciales, the Peltigerales, the Ostropomycetidae, the Acarosporomycetidae, the Verrucariales, the Arthoniomycetidae and the Lichinales. The genes recovered were included in a refined phylogenetic analysis. The hypothesis that lichens symbiotic with a nitrogen-fixing cyanobacterium as a primary photobiont or lichens living in high nitrogen environments lose the plant-like ammonium transporters was upheld, but did not account for additional losses of ammonium transporters/ammonia permeases in the lichens from the Acarosporomycetidae, Chaetotheriomycetes and Arthoniomycetes. In addition, the four ammonium transporter/ammonia permease genes from Cladonia grayi were shown to be functional by expressing the lichen genes in a strain of Saccharomyces cerevisiae in which all three native ammonium transporters were deleted, and assaying for growth on limiting ammonia as a sole nitrogen source. Conclusions Given sufficient coverage, next-generation sequencing technology can definitively address the loss of a gene in a genome when using environmental DNA isolated from lichen thalli collected from their natural habitats. Lichen-forming fungi have been losing ammonium transporters/ammonia permease genes at a slower rate than the most closely related non-lichenized lineages. These horizontally transferred genes in the Cladonia grayi genome encode functional ammonium transporters/ammonia permeases.
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New insights into roles of acidocalcisomes and contractile vacuole complex in osmoregulation in protists. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 305:69-113. [PMID: 23890380 DOI: 10.1016/b978-0-12-407695-2.00002-0] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
While free-living protists are usually subjected to hyposmotic environments, parasitic protists are also in contact with hyperosmotic habitats. Recent work in one of these parasites, Trypanosoma cruzi, has revealed that its contractile vacuole complex, which usually collects and expels excess water as a mechanism of regulatory volume decrease after hyposmotic stress, has also a role in cell shrinking when the cells are submitted to hyperosmotic stress. Trypanosomes also have an acidic calcium store rich in polyphosphate (polyP), named the acidocalcisome, which is involved in their response to osmotic stress. Here, we review newly emerging insights on the role of acidocalcisomes and the contractile vacuole complex in the cellular response to hyposmotic and hyperosmotic stresses. We also review the current state of knowledge on the composition of these organelles and their other roles in calcium homeostasis and protein trafficking.
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Flegr J, Geryk J, Volný J, Klose J, Cernochová D. Rhesus factor modulation of effects of smoking and age on psychomotor performance, intelligence, personality profile, and health in Czech soldiers. PLoS One 2012; 7:e49478. [PMID: 23209579 PMCID: PMC3509049 DOI: 10.1371/journal.pone.0049478] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Accepted: 10/10/2012] [Indexed: 01/02/2023] Open
Abstract
Background Rhesus-positive and rhesus-negative persons differ in the presence-absence of highly immunogenic RhD protein on the erythrocyte membrane. This protein is a component of NH3 or CO2 pump whose physiological role is unknown. Several recent studies have shown that RhD positivity protects against effects of latent toxoplasmosis on motor performance and personality. It is not known, however, whether the RhD phenotype modifies exclusively the response of the body to toxoplasmosis or whether it also influences effects of other factors. Methodology/Principal Findings In the present cohort study, we searched for the effects of age and smoking on performance, intelligence, personality and self-estimated health and wellness in about 3800 draftees. We found that the positive effect of age on performance and intelligence was stronger in RhD-positive soldiers, while the negative effect of smoking on performance and intelligence was of similar size regardless of the RhD phenotype. The effect of age on four Cattell's personality factors, i.e., dominance (E), radicalism (Q1), self-sentiment integration (Q3), and ergic tension (Q4), and on Cloninger's factor reward dependency (RD) was stronger for RhD-negative than RhD-positive subjects, while the effect of smoking on the number of viral and bacterial diseases was about three times stronger for RhD-negative than RhD-positive subjects. Conclusions RhD phenotype modulates the influence not only of latent toxoplasmosis, but also of at least two other potentially detrimental factors, age and smoking, on human behavior and physiology. The negative effect of smoking on health (estimated on the basis of the self-rated number of common viral and bacterial diseases in the past year) was much stronger in RhD-negative than RhD-positive subjects. It is critically needed to confirm the differences in health response to smoking between RhD-positive and RhD-negative subjects by objective medical examination in future studies.
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Affiliation(s)
- Jaroslav Flegr
- Faculty of Science, Charles University in Prague, Prague, Czech Republic.
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36
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Wright PA, Wood CM. Seven things fish know about ammonia and we don't. Respir Physiol Neurobiol 2012; 184:231-40. [PMID: 22910326 DOI: 10.1016/j.resp.2012.07.003] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Revised: 07/03/2012] [Accepted: 07/04/2012] [Indexed: 01/01/2023]
Abstract
In this review we pose the following seven questions related to ammonia and fish that represent gaps in our knowledge. 1. How is ammonia excretion linked to sodium uptake in freshwater fish? 2. How much does branchial ammonia excretion in seawater teleosts depend on Rhesus (Rh) glycoprotein-mediated NH(3) diffusion? 3. How do fish maintain ammonia excretion rates if branchial surface area is reduced or compromised? 4. Why does high environmental ammonia change the transepithelial potential across the gills? 5. Does high environmental ammonia increase gill surface area in ammonia tolerant fish but decrease gill surface area in ammonia intolerant fish? 6. How does ammonia contribute to ventilatory control? 7. What do Rh proteins do when they are not transporting ammonia? Mini reviews on each topic, which are able to present only partial answers to each question at present, are followed by further questions and/or suggestions for research approaches targeted to uncover answers.
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Affiliation(s)
- Patricia A Wright
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada.
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37
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Perry GH, Xue Y, Smith RS, Meyer WK, Çalışkan M, Yanez-Cuna O, Lee AS, Gutiérrez-Arcelus M, Ober C, Hollox EJ, Tyler-Smith C, Lee C. Evolutionary genetics of the human Rh blood group system. Hum Genet 2012; 131:1205-16. [PMID: 22367406 PMCID: PMC3378649 DOI: 10.1007/s00439-012-1147-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Accepted: 02/12/2012] [Indexed: 10/28/2022]
Abstract
The evolutionary history of variation in the human Rh blood group system, determined by variants in the RHD and RHCE genes, has long been an unresolved puzzle in human genetics. Prior to medical treatments and interventions developed in the last century, the D-positive (RhD positive) children of D-negative (RhD negative) women were at risk for hemolytic disease of the newborn, if the mother produced anti-D antibodies following sensitization to the blood of a previous D-positive child. Given the deleterious fitness consequences of this disease, the appreciable frequencies in European populations of the responsible RHD gene deletion variant (for example, 0.43 in our study) seem surprising. In this study, we used new molecular and genomic data generated from four HapMap population samples to test the idea that positive selection for an as-of-yet unknown fitness benefit of the RHD deletion may have offset the otherwise negative fitness effects of hemolytic disease of the newborn. We found no evidence that positive natural selection affected the frequency of the RHD deletion. Thus, the initial rise to intermediate frequency of the RHD deletion in European populations may simply be explained by genetic drift/founder effect, or by an older or more complex sweep that we are insufficiently powered to detect. However, our simulations recapitulate previous findings that selection on the RHD deletion is frequency dependent and weak or absent near 0.5. Therefore, once such a frequency was achieved, it could have been maintained by a relatively small amount of genetic drift. We unexpectedly observed evidence for positive selection on the C allele of RHCE in non-African populations (on chromosomes with intact copies of the RHD gene) in the form of an unusually high F( ST ) value and the high frequency of a single haplotype carrying the C allele. RhCE function is not well understood, but the C/c antigenic variant is clinically relevant and can result in hemolytic disease of the newborn, albeit much less commonly and severely than that related to the D-negative blood type. Therefore, the potential fitness benefits of the RHCE C allele are currently unknown but merit further exploration.
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Affiliation(s)
- George H. Perry
- Department of Anthropology, Pennsylvania State University, University Park, PA 16801 USA
- Department of Pathology, Brigham & Women’s Hospital, Boston, MA 02115, USA
| | - Yali Xue
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
| | - Richard S. Smith
- Department of Pathology, Brigham & Women’s Hospital, Boston, MA 02115, USA
- Harvard Medical School, Boston, MA 02115 USA
| | - Wynn K. Meyer
- Department of Human Genetics, University of Chicago, Chicago, IL 60637, USA
| | - Minal Çalışkan
- Department of Human Genetics, University of Chicago, Chicago, IL 60637, USA
| | - Omar Yanez-Cuna
- Department of Pathology, Brigham & Women’s Hospital, Boston, MA 02115, USA
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, México
| | - Arthur S. Lee
- Department of Pathology, Brigham & Women’s Hospital, Boston, MA 02115, USA
| | - María Gutiérrez-Arcelus
- Department of Pathology, Brigham & Women’s Hospital, Boston, MA 02115, USA
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, México
| | - Carole Ober
- Department of Human Genetics, University of Chicago, Chicago, IL 60637, USA
| | - Edward J. Hollox
- Department of Genetics, University of Leicester, Leicester LE1 7RH, UK
| | | | - Charles Lee
- Department of Pathology, Brigham & Women’s Hospital, Boston, MA 02115, USA
- Harvard Medical School, Boston, MA 02115 USA
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McDonald TR, Dietrich FS, Lutzoni F. Multiple horizontal gene transfers of ammonium transporters/ammonia permeases from prokaryotes to eukaryotes: toward a new functional and evolutionary classification. Mol Biol Evol 2012; 29:51-60. [PMID: 21680869 PMCID: PMC3383101 DOI: 10.1093/molbev/msr123] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The proteins of the ammonium transporter/methylammonium permease/Rhesus factor family (AMT/MEP/Rh family) are responsible for the movement of ammonia or ammonium ions across the cell membrane. Although it has been established that the Rh proteins are distantly related to the other members of the family, the evolutionary history of the AMT/MEP/Rh family remains unclear. Here, we use phylogenetic analysis to infer the evolutionary history of this family of proteins across 191 genomes representing all main lineages of life and to provide a new classification of the proteins in this family. Our phylogenetic analysis suggests that what has heretofore been conceived of as a protein family with two clades (AMT/MEP and Rh) is instead a protein family with three clades (AMT, MEP, and Rh). We show that the AMT/MEP/Rh family illustrates two contrasting modes of gene transmission: The AMT family as defined here exhibits vertical gene transfer (i.e., standard parent-to-offspring inheritance), whereas the MEP family as defined here is characterized by several ancient independent horizontal gene transfers (HGTs). These ancient HGT events include a gene replacement during the early evolution of the fungi, which could be a defining trait for the kingdom Fungi, a gene gain from hyperthermophilic chemoautolithotrophic prokaryotes during the early evolution of land plants (Embryophyta), and an independent gain of this same gene in the filamentous ascomycetes (Pezizomycotina) that was subsequently lost in most lineages but retained in even distantly related lichenized fungi. This recircumscription of the ammonium transporters/ammonia permeases family into MEP and AMT families informs the debate on the mechanism of transport in these proteins and on the nature of the transported molecule because published crystal structures of proteins from the MEP and Rh clades may not be representative of the AMT clade. The clades as depicted in this phylogenetic study appear to correspond to functionally different groups, with AMTs and ammonia permeases forming two distinct and possibly monophyletic groups.
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Wang Y, Duanmu D, Spalding MH. Carbon dioxide concentrating mechanism in Chlamydomonas reinhardtii: inorganic carbon transport and CO2 recapture. PHOTOSYNTHESIS RESEARCH 2011; 109:115-22. [PMID: 21409558 DOI: 10.1007/s11120-011-9643-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Accepted: 02/28/2011] [Indexed: 05/04/2023]
Abstract
Many microalgae are capable of acclimating to CO(2) limited environments by operating a CO(2) concentrating mechanism (CCM), which is driven by various energy-coupled inorganic carbon (Ci; CO(2) and HCO(3)(-)) uptake systems. Chlamydomonas reinhardtii (hereafter, Chlamydomonas), a versatile genetic model organism, has been used for several decades to exemplify the active Ci transport in eukaryotic algae, but only recently have many molecular details behind these Ci uptake systems emerged. Recent advances in genetic and molecular approaches, combined with the genome sequencing of Chlamydomonas and several other eukaryotic algae have unraveled some unique characteristics associated with the Ci uptake mechanism and the Ci-recapture system in eukaryotic microalgae. Several good candidate genes for Ci transporters in Chlamydomonas have been identified, and a few specific gene products have been linked with the Ci uptake systems associated with the different acclimation states. This review will focus on the latest studies on characterization of functional components involved in the Ci uptake and the Ci-recapture in Chlamydomonas.
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Affiliation(s)
- Yingjun Wang
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA
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40
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Scott K. Out of thin air: sensory detection of oxygen and carbon dioxide. Neuron 2011; 69:194-202. [PMID: 21262460 DOI: 10.1016/j.neuron.2010.12.018] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/17/2010] [Indexed: 10/18/2022]
Abstract
Oxygen (O₂) and carbon dioxide (CO₂) levels vary in different environments and locally fluctuate during respiration and photosynthesis. Recent studies in diverse animals have identified sensory neurons that detect these external variations and direct a variety of behaviors. Detection allows animals to stay within a preferred environment as well as identify potential food or dangers. The complexity of sensation is reflected in the fact that neurons compartmentalize detection into increases, decreases, and short-range and long-range cues. Animals also adjust their responses to these prevalent signals in the context of other cues, allowing for flexible behaviors. In general, the molecular mechanisms for detection suggest that sensory neurons adopted ancient strategies for cellular detection and coupled them to brain activity and behavior. This review highlights the multiple strategies that animals use to extract information about their environment from variations in O₂ and CO₂.
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Affiliation(s)
- Kristin Scott
- Department of Molecular and Cell Biology and Helen Wills Neuroscience Institute, 16 Barker Hall, University of California, Berkeley, Berkeley, CA 94720, USA.
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41
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Periplasmic vestibule plays an important role for solute recruitment, selectivity, and gating in the Rh/Amt/MEP superfamily. Proc Natl Acad Sci U S A 2011; 108:3970-5. [PMID: 21368153 DOI: 10.1073/pnas.1007240108] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
AmtB, a member of the Rh/Amt/MEP superfamily, is responsible for ammonia transport in Escherichia coli. The ammonia pathway in AmtB consists of a narrow hydrophobic lumen in between hydrophilic periplasmic and cytoplasmic vestibules. A series of molecular dynamics simulations (greater than 0.4 μs in total) were performed to determine the mechanism of solute recruitments and selectivity by the periplasmic vestibule. The results show that the periplasmic vestibule plays a crucial role in solute selectivity, and its solute preferences follow the order of NH4(+) > NH3 > CO2. Based on our results, NH4(+) recruitment is initiated by its interaction with either E70 or E225, highly conserved residues located at the entrance of the vestibule. Subsequently, the backbone carbonyl groups at the periplasmic vestibule direct NH4(+) to the conserved aromatic cage at the bottom of the vestibule (known as the Am1 site). The umbrella sampling simulations suggest that the conserved residue D160 is not directly involved in the ammonia conduction; rather its main function is to keep the structure of periplasmic vestibule intact. The MD simulations also revealed that two partially stacked phenyl rings of F107 and F215, separating the periplasmic vestibule from the hydrophobic lumen, flip open and closed simultaneously with a frequency of approximately 10(8) flipping events per second. These results show how the periplasmic vestibule selectively recruits NH4(+) to the Am1 site, and also that the synchronized flipping of two phenyl rings potentially facilitates the solute transition from the periplasmic vestibule to the hydrophobic lumen in the Rh/Amt/MEP superfamily.
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Hub JS, Winkler FK, Merrick M, de Groot BL. Potentials of mean force and permeabilities for carbon dioxide, ammonia, and water flux across a Rhesus protein channel and lipid membranes. J Am Chem Soc 2010; 132:13251-63. [PMID: 20815391 DOI: 10.1021/ja102133x] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
As a member of the ubiquitous ammonium transporter/methylamine permease/Rhesus (Amt/MEP/Rh) family of membrane protein channels, the 50 kDa Rhesus channel (Rh50) has been implicated in ammonia (NH(3)) and, more recently, also in carbon dioxide (CO(2)) transport. Here we present molecular dynamics simulations of spontaneous full permeation events of ammonia and carbon dioxide across Rh50 from Nitrosomonas europaea. The simulations show that Rh50 is functional in its crystallographic conformation, without the requirement for a major conformational change or the action of a protein partner. To assess the physiological relevance of NH(3) and CO(2) permeation across Rh50, we have computed potentials of mean force (PMFs) and permeabilities for NH(3) and CO(2) flux across Rh50 and compare them to permeation through a wide range of lipid membranes, either composed of pure lipids or composed of lipids plus an increasing cholesterol content. According to the PMFs, Rh50 is expected to enhance NH(3) flux across dense membranes, such as membranes with a substantial cholesterol content. Although cholesterol reduces the intrinsic CO(2) permeability of lipid membranes, the CO(2) permeabilities of all membranes studied here are too high to allow significant Rh50-mediated CO(2) flux. The increased barrier in the PMF for water permeation across Rh50 shows that Rh50 discriminates 40-fold between water and NH(3). Thus, Rh50 channels complement aquaporins, allowing the cell to regulate water and NH(3) flux independently. The PMFs for methylamine and NH(3) are virtually identical, suggesting that methylamine provides an excellent model for NH(3) in functional experiments.
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Affiliation(s)
- Jochen S Hub
- Department of Cell and Molecular Biology, Uppsala University, Box 596, 75124 Uppsala, Sweden.
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43
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Baines A. Evolution of the spectrin-based membrane skeleton. Transfus Clin Biol 2010; 17:95-103. [DOI: 10.1016/j.tracli.2010.06.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Accepted: 06/23/2010] [Indexed: 12/16/2022]
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Baines AJ. The spectrin-ankyrin-4.1-adducin membrane skeleton: adapting eukaryotic cells to the demands of animal life. PROTOPLASMA 2010; 244:99-131. [PMID: 20668894 DOI: 10.1007/s00709-010-0181-1] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Accepted: 07/05/2010] [Indexed: 05/29/2023]
Abstract
The cells in animals face unique demands beyond those encountered by their unicellular eukaryotic ancestors. For example, the forces engendered by the movement of animals places stresses on membranes of a different nature than those confronting free-living cells. The integration of cells into tissues, as well as the integration of tissue function into whole animal physiology, requires specialisation of membrane domains and the formation of signalling complexes. With the evolution of mammals, the specialisation of cell types has been taken to an extreme with the advent of the non-nucleated mammalian red blood cell. These and other adaptations to animal life seem to require four proteins--spectrin, ankyrin, 4.1 and adducin--which emerged during eumetazoan evolution. Spectrin, an actin cross-linking protein, was probably the earliest of these, with ankyrin, adducin and 4.1 only appearing as tissues evolved. The interaction of spectrin with ankyrin is probably a prerequisite for the formation of tissues; only with the advent of vertebrates did 4.1 acquires the ability to bind spectrin and actin. The latter activity seems to allow the spectrin complex to regulate the cell surface accumulation of a wide variety of proteins. Functionally, the spectrin-ankyrin-4.1-adducin complex is implicated in the formation of apical and basolateral domains, in aspects of membrane trafficking, in assembly of certain signalling and cell adhesion complexes and in providing stability to otherwise mechanically fragile cell membranes. Defects in this complex are manifest in a variety of hereditary diseases, including deafness, cardiac arrhythmia, spinocerebellar ataxia, as well as hereditary haemolytic anaemias. Some of these proteins also function as tumor suppressors. The spectrin-ankyrin-4.1-adducin complex represents a remarkable system that underpins animal life; it has been adapted to many different functions at different times during animal evolution.
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Affiliation(s)
- Anthony J Baines
- School of Biosciences and Centre for Biomedical Informatics, University of Kent, Canterbury, CT2 7NJ, UK.
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45
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Nakhoul NL, Abdulnour-Nakhoul SM, Boulpaep EL, Rabon E, Schmidt E, Hamm LL. Substrate specificity of Rhbg: ammonium and methyl ammonium transport. Am J Physiol Cell Physiol 2010; 299:C695-705. [PMID: 20592240 DOI: 10.1152/ajpcell.00019.2010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Rhbg is a nonerythroid membrane glycoprotein belonging to the Rh antigen family. In the kidney, Rhbg is expressed at the basolateral membrane of intercalated cells of the distal nephron and is involved in NH4+ transport. We investigated the substrate specificity of Rhbg by comparing transport of NH3/NH4+ with that of methyl amine (hydrochloride) (MA/MA+), often used to replace NH3/NH4+, in oocytes expressing Rhbg. Methyl amine (HCl) in solution exists as neutral methyl amine (MA) in equilibrium with the protonated methyl ammonium (MA+). To assess transport, we used ion-selective microelectrodes and voltage-clamp experiments to measure NH3/NH4+- and MA/MA+-induced intracellular pH (pH(i)) changes and whole cell currents. Our data showed that in Rhbg oocytes, NH3/NH4+ caused an inward current and decrease in pH(i) consistent with electrogenic NH4+ transport. These changes were significantly larger than in H2O-injected oocytes. The NH3/NH4+-induced current was not inhibited in the presence of barium or in the absence of Na+. In Rhbg oocytes, MA/MA+ caused an inward current but an increase (rather than a decrease) in pH(i). MA/MA+ did not cause any changes in H2O-injected oocytes. The MA/MA+-induced current and pH(i) increase were saturated at higher concentrations of MA/MA+. Amiloride inhibited MA/MA+-induced current and the increase in pH(i) in oocytes expressing Rhbg but had no effect on control oocytes. These results indicate that MA/MA+ is transported by Rhbg but differently than NH3/NH4+. The protonated MA+ is likely a direct substrate whose transport resembles that of NH4+. Transport of electroneutral MA is also enhanced by expression of Rhbg.
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Affiliation(s)
- Nazih L Nakhoul
- Dept. of Medicine, Section of Nephrology, SL-45, Tulane Univ. School of Medicine, 1430 Tulane Ave., New Orleans, LA 70112, USA.
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van den Akker E, Satchwell TJ, Williamson RC, Toye AM. Band 3 multiprotein complexes in the red cell membrane; of mice and men. Blood Cells Mol Dis 2010; 45:1-8. [DOI: 10.1016/j.bcmd.2010.02.019] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Accepted: 02/04/2010] [Indexed: 02/02/2023]
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Flegr J, Novotná M, Fialová A, Kolbeková P, Gašová Z. The influence of RhD phenotype on toxoplasmosis- and age-associated changes in personality profile of blood donors. Folia Parasitol (Praha) 2010. [DOI: 10.14411/fp.2010.018] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Nawata CM, Wood CM, O'Donnell MJ. Functional characterization of Rhesus glycoproteins from an ammoniotelic teleost, the rainbow trout, using oocyte expression and SIET analysis. J Exp Biol 2010; 213:1049-59. [PMID: 20228341 DOI: 10.1242/jeb.038752] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
SUMMARY
Recent experimental evidence from rainbow trout suggests that gill ammonia transport may be mediated in part via Rhesus (Rh) glycoproteins. In this study we analyzed the transport properties of trout Rh proteins (Rhag, Rhbg1, Rhbg2, Rhcg1, Rhcg2, Rh30-like) expressed in Xenopus oocytes, using the radiolabeled ammonia analogue [14C]methylamine, and the scanning ion electrode technique (SIET). All of the trout Rh proteins, except Rh30-like, facilitated methylamine uptake. Uptake was saturable, with Km values ranging from 4.6 to 8.9 mmol l−1. Raising external pH from 7.5 to 8.5 resulted in 3- to 4-fold elevations in Jmax values for methylamine; Km values were unchanged when expressed as total or protonated methylamine. Efflux of methylamine was also facilitated in Rh-expressing oocytes. Efflux and influx rates were stimulated by a pH gradient, with higher rates observed with steeper H+ gradients. NH4Cl inhibited methylamine uptake in oocytes expressing Rhbg1 or Rhcg2. When external pH was elevated from 7.5 to 8.5, the Ki for ammonia against methylamine transport was 35–40% lower when expressed as total ammonia or NH4+, but 5- to 6-fold higher when expressed as NH3. With SIET we confirmed that ammonia uptake was facilitated by Rhag and Rhcg2, but not Rh30-like proteins. Ammonia uptake was saturable, with a comparable Jmax but lower Km value than for total or protonated methylamine. At low substrate concentrations, the ammonia uptake rate was greater than that of methylamine. The Km for total ammonia (560 μmol l−1) lies within the physiological range for trout. The results are consistent with a model whereby NH4+ initially binds, but NH3 passes through the Rh channels. We propose that Rh glycoproteins in the trout gill are low affinity, high capacity ammonia transporters that exploit the favorable pH gradient formed by the acidified gill boundary layer in order to facilitate rapid ammonia efflux when plasma ammonia concentrations are elevated.
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Affiliation(s)
- C. Michele Nawata
- Department of Biology, McMaster University, 1280 Main St. West, Hamilton, Ontario, Canada L8S 4K1
| | - Chris M. Wood
- Department of Biology, McMaster University, 1280 Main St. West, Hamilton, Ontario, Canada L8S 4K1
| | - Michael J. O'Donnell
- Department of Biology, McMaster University, 1280 Main St. West, Hamilton, Ontario, Canada L8S 4K1
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Huang CH, Ye M. The Rh protein family: gene evolution, membrane biology, and disease association. Cell Mol Life Sci 2010; 67:1203-18. [PMID: 19953292 PMCID: PMC11115862 DOI: 10.1007/s00018-009-0217-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2009] [Revised: 11/10/2009] [Accepted: 11/12/2009] [Indexed: 11/25/2022]
Abstract
The Rh (Rhesus) genes encode a family of conserved proteins that share a structural fold of 12 transmembrane helices with members of the major facilitator superfamily. Interest in this family has arisen from the discovery of Rh factor's involvement in hemolytic disease in the fetus and newborn, and of its homologs widely expressed in epithelial tissues. The Rh factor and Rh-associated glycoprotein (RhAG), with epithelial cousins RhBG and RhCG, form four subgroups conferring upon vertebrates a genealogical commonality. The past decade has heralded significant advances in understanding the phylogenetics, allelic diversity, crystal structure, and biological function of Rh proteins. This review describes recent progress on this family and the molecular insights gleaned from its gene evolution, membrane biology, and disease association. The focus is on its long evolutionary history and surprising structural conservation from prokaryotes to humans, pointing to the importance of its functional role, related to but distinct from ammonium transport proteins.
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Affiliation(s)
- Cheng-Han Huang
- Laboratory of Biochemistry and Molecular Genetics, Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY 10065, USA.
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Wu SC, Horng JL, Liu ST, Hwang PP, Wen ZH, Lin CS, Lin LY. Ammonium-dependent sodium uptake in mitochondrion-rich cells of medaka (Oryzias latipes) larvae. Am J Physiol Cell Physiol 2010; 298:C237-50. [DOI: 10.1152/ajpcell.00373.2009] [Citation(s) in RCA: 131] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
In this study, a scanning ion-selective electrode technique (SIET) was applied to measure H+, Na+, and NH4+ gradients and apparent fluxes at specific cells on the skin of medaka larvae. Na+ uptake and NH3/NH4+ excretion were detected at most mitochondrion-rich cells (MRCs). H+ probing at MRCs revealed two group of MRCs, i.e., acid-secreting and base-secreting MRCs. Treatment with EIPA (100 μM) blocked 35% of the NH3/NH4+ secretion and 54% of the Na+ uptake, suggesting that the Na+/H+ exchanger (NHE) is involved in Na+ and NH3/NH4+ transport. Low-Na+ water (<0.001 mM) or high-NH4+ (5 mM) acclimation simultaneously increased Na+ uptake and NH3/NH4+ excretion but decreased or even reversed the H+ gradient at the skin and MRCs. The correlation between NH4+ production and H+ consumption at the skin surface suggests that MRCs excrete nonionic NH3 (base) by an acid-trapping mechanism. Raising the external NH4+ significantly blocked NH3/NH4+ excretion and Na+ uptake. In contrast, raising the acidity of the water (pH 7 to pH 6) enhanced NH3/NH4+ excretion and Na+ uptake by MRCs. In situ hybridization and real-time PCR showed that the mRNAs of the Na+/H+ exchanger ( slc9a3) and Rhesus glycoproteins ( Rhcg1 and Rhbg) were colocalized in MRCs of medaka, and their expressions were induced by low-Na+ acclimation. This study suggests a novel Na+/NH4+ exchange pathway in apical membranes of MRCs, in which a coupled NHE and Rh glycoprotein is involved and the Rh glycoprotein may drive the NHE by generating H+ gradients across apical membranes of MRCs.
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Affiliation(s)
- Shu-Chen Wu
- Department of Life Science, National Taiwan Normal University, Taipei, Taiwan, Republic of China
| | - Jiun-Lin Horng
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan, Republic of China; and
| | - Sian-Tai Liu
- Department of Life Science, National Taiwan Normal University, Taipei, Taiwan, Republic of China
| | - Pung-Pung Hwang
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan, Republic of China; and
| | - Zhi-Hong Wen
- Department of Marine Biotechnology and Resources, College of Marine Science and Division of Marine Biotechnology, Asia-Pacific Ocean Research Center, National Sun Yat-sen University, Kaohsiung, Taiwan, Republic of China
| | - Chan-Shing Lin
- Department of Marine Biotechnology and Resources, College of Marine Science and Division of Marine Biotechnology, Asia-Pacific Ocean Research Center, National Sun Yat-sen University, Kaohsiung, Taiwan, Republic of China
| | - Li-Yih Lin
- Department of Life Science, National Taiwan Normal University, Taipei, Taiwan, Republic of China
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