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Zerbetto De Palma G, Recoulat Angelini AA, Vitali V, González Flecha FL, Alleva K. Cooperativity in regulation of membrane protein function: phenomenological analysis of the effects of pH and phospholipids. Biophys Rev 2023; 15:721-731. [PMID: 37681089 PMCID: PMC10480370 DOI: 10.1007/s12551-023-01095-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 07/01/2023] [Indexed: 09/09/2023] Open
Abstract
Interaction between membrane proteins and ligands plays a key role in governing a wide spectrum of cellular processes. These interactions can provide a cooperative-type regulation of protein function. A wide variety of proteins, including enzymes, channels, transporters, and receptors, displays cooperative behavior in their interactions with ligands. Moreover, the ligands involved encompass a vast diversity and include specific molecules or ions that bind to specific binding sites. In this review, our particular focus is on the interaction between integral membrane proteins and ligands that can present multiple "binding sites", such as protons or membrane phospholipids. The study of the interaction that protons or lipids have with membrane proteins often presents challenges for classical mechanistic modeling approaches. In this regard, we show that, like Hill's pioneering work on hemoglobin regulation, phenomenological modeling constitutes a powerful tool for capturing essential features of these systems.
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Affiliation(s)
- Gerardo Zerbetto De Palma
- Facultad de Farmacia y Bioquímica, Departamento de Fisicomatemática, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Biotecnología, Universidad Nacional de Hurlingham, Villa Tesei, Buenos Aires, Argentina
- Instituto de Química y Fisicoquímica Biológica (IQUIFIB), CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Alvaro A. Recoulat Angelini
- Instituto de Química y Fisicoquímica Biológica (IQUIFIB), CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Victoria Vitali
- Facultad de Farmacia y Bioquímica, Departamento de Fisicomatemática, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Química y Fisicoquímica Biológica (IQUIFIB), CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - F. Luis. González Flecha
- Instituto de Química y Fisicoquímica Biológica (IQUIFIB), CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Karina Alleva
- Facultad de Farmacia y Bioquímica, Departamento de Fisicomatemática, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Química y Fisicoquímica Biológica (IQUIFIB), CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
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Aquaporins Display a Diversity in their Substrates. J Membr Biol 2023; 256:1-23. [PMID: 35986775 DOI: 10.1007/s00232-022-00257-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 07/13/2022] [Indexed: 02/07/2023]
Abstract
Aquaporins constitute a family of transmembrane proteins that function to transport water and other small solutes across the cell membrane. Aquaporins family members are found in diverse life forms. Aquaporins share the common structural fold consisting of six transmembrane alpha helices with a central water-transporting channel. Four such monomers assemble together to form tetramers as their biological unit. Initially, aquaporins were discovered as water-transporting channels, but several studies supported their involvement in mediating the facilitated diffusion of different solutes. The so-called water channel is able to transport a variety of substrates ranging from a neutral molecule to a charged molecule or a small molecule to a bulky molecule or even a gas molecule. This article gives an overview of a diverse range of substrates conducted by aquaporin family members. Prime focus is on human aquaporins where aquaporins show a wide tissue distribution and substrate specificity leading to various physiological functions. This review also highlights the structural mechanisms leading to the transport of water and glycerol. More research is needed to understand how one common fold enables the aquaporins to transport an array of solutes.
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3
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Pimpão C, Wragg D, da Silva IV, Casini A, Soveral G. Aquaglyceroporin Modulators as Emergent Pharmacological Molecules for Human Diseases. Front Mol Biosci 2022; 9:845237. [PMID: 35187089 PMCID: PMC8850838 DOI: 10.3389/fmolb.2022.845237] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 01/13/2022] [Indexed: 12/26/2022] Open
Abstract
Aquaglyceroporins, a sub-class of aquaporins that facilitate the diffusion of water, glycerol and other small uncharged solutes across cell membranes, have been recognized for their important role in human physiology and their involvement in multiple disorders, mostly related to disturbed energy homeostasis. Aquaglyceroporins dysfunction in a variety of pathological conditions highlighted their targeting as novel therapeutic strategies, boosting the search for potent and selective modulators with pharmacological properties. The identification of selective inhibitors with potential clinical applications has been challenging, relying on accurate assays to measure membrane glycerol permeability and validate effective functional blockers. Additionally, biologicals such as hormones and natural compounds have been revealed as alternative strategies to modulate aquaglyceroporins via their gene and protein expression. This review summarizes the current knowledge of aquaglyceroporins’ involvement in several pathologies and the experimental approaches used to evaluate glycerol permeability and aquaglyceroporin modulation. In addition, we provide an update on aquaglyceroporins modulators reported to impact disease, unveiling aquaglyceroporin pharmacological targeting as a promising approach for innovative therapeutics.
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Affiliation(s)
- Catarina Pimpão
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisboa, Portugal
- Department of Pharmaceutical Sciences and Medicines, Faculty of Pharmacy, Universidade de Lisboa, Lisboa, Portugal
| | - Darren Wragg
- Department of Chemistry, Technical University of Munich, Munich, Germany
| | - Inês V. da Silva
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisboa, Portugal
- Department of Pharmaceutical Sciences and Medicines, Faculty of Pharmacy, Universidade de Lisboa, Lisboa, Portugal
| | - Angela Casini
- Department of Chemistry, Technical University of Munich, Munich, Germany
- *Correspondence: Angela Casini, ; Graça Soveral,
| | - Graça Soveral
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisboa, Portugal
- Department of Pharmaceutical Sciences and Medicines, Faculty of Pharmacy, Universidade de Lisboa, Lisboa, Portugal
- *Correspondence: Angela Casini, ; Graça Soveral,
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Falato M, Chan R, Chen LY. Aquaglyceroporin AQP7's affinity for its substrate glycerol: Have we reached convergence in the computed values of glycerol-aquaglyceroporin affinity? RSC Adv 2022; 12:3128-3135. [PMID: 35222995 PMCID: PMC8870571 DOI: 10.1039/d1ra07367b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Accepted: 01/18/2022] [Indexed: 12/02/2022] Open
Abstract
AQP7 is one of the four human aquaglyceroporins that facilitate glycerol transport across the cell membrane, a biophysical process that is essential in human physiology. Therefore, it is interesting to compute AQP7's affinity for its substrate (glycerol) with reasonable certainty to compare with the experimental data suggesting high affinity in contrast with most computational studies predicting low affinity. In this study aimed at computing the AQP7-glycerol affinity with high confidence, we implemented a direct computation of the affinity from unbiased equilibrium molecular dynamics (MD) simulations of three all-atom systems constituted with 0.16M, 4.32M, and 10.23M atoms, respectively. These three sets of simulations manifested a fundamental physics law that the intrinsic fluctuations of pressure in a system are inversely proportional to the system size (the number of atoms in it). These simulations showed that the computed values of glycerol-AQP7 affinity are dependent upon the system size (the inverse affinity estimations were, respectively, 47.3 mM, 1.6 mM, and 0.92 mM for the three model systems). In this, we obtained a lower bound for the AQP7-glycerol affinity (an upper bound for the dissociation constant). Namely, the AQP7-glycerol affinity is stronger than 1087/M (the dissociation constant is less than 0.92 mM). Additionally, we conducted hyper steered MD (hSMD) simulations to map out the Gibbs free-energy profile. From the free-energy profile, we produced an independent computation of the AQP7-glycerol dissociation constant being approximately 0.18 mM.
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Affiliation(s)
- Michael Falato
- Department of Physics, University of Texas at San AntonioSan AntonioTexas 78249USA
| | - Ruth Chan
- Department of Physics, University of Texas at San AntonioSan AntonioTexas 78249USA
| | - Liao Y. Chen
- Department of Physics, University of Texas at San AntonioSan AntonioTexas 78249USA
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Calamita G, Delporte C. Involvement of aquaglyceroporins in energy metabolism in health and disease. Biochimie 2021; 188:20-34. [PMID: 33689852 DOI: 10.1016/j.biochi.2021.03.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/23/2021] [Accepted: 03/01/2021] [Indexed: 11/27/2022]
Abstract
Aquaglyceroporins are a group of the aquaporin (AQP) family of transmembrane water channels. While AQPs facilitate the passage of water, small solutes, and gases across biological membranes, aquaglyceroporins allow passage of water, glycerol, urea and some other solutes. Thanks to their glycerol permeability, aquaglyceroporins are involved in energy homeostasis. This review provides an overview of what is currently known concerning the functional implication and control of aquaglyceroporins in tissues involved in energy metabolism, i.e. liver, adipose tissue and endocrine pancreas. The expression, role and (dys)regulation of aquaglyceroporins in disorders affecting energy metabolism, and the potential relevance of aquaglyceroporins as drug targets to treat the alterations of the energy balance is also addressed.
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Affiliation(s)
- Giuseppe Calamita
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari "Aldo Moro", Bari, Italy
| | - Christine Delporte
- Laboratory of Pathophysiological and Nutritional Biochemistry, Université Libre de Bruxelles, Brussels, Belgium.
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Rodriguez RA, Chan R, Liang H, Chen LY. Quantitative study of unsaturated transport of glycerol through aquaglyceroporin that has high affinity for glycerol. RSC Adv 2020; 10:34203-34214. [PMID: 32944226 PMCID: PMC7494219 DOI: 10.1039/d0ra05262k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 09/08/2020] [Indexed: 11/21/2022] Open
Abstract
The structures of several aquaglyceroporins have been resolved to atomic resolution showing two or more glycerols bound inside a channel and confirming a glycerol-facilitator's affinity for its substrate glycerol. However, the kinetics data of glycerol transport experiments all point to unsaturated transport that is characteristic of low substrate affinity in terms of the Michaelis-Menten kinetics. In this article, we present an in silico-in vitro research focused on AQP3, one of the human aquaglyceroporins that is natively expressed in the abundantly available erythrocytes. We conducted 2.1 μs in silico simulations of AQP3 embedded in a model erythrocyte membrane with intracellular-extracellular asymmetries in leaflet lipid compositions and compartment salt ions. From the equilibrium molecular dynamics (MD) simulations, we elucidated the mechanism of glycerol transport at high substrate concentrations. From the steered MD simulations, we computed the Gibbs free-energy profile throughout the AQP3 channel. From the free-energy profile, we quantified the kinetics of glycerol transport that is unsaturated due to glycerol-glycerol interactions mediated by AQP3 resulting in the concerted movement of two glycerol molecules for the transport of one glycerol molecule across the cell membrane. We conducted in vitro experiments on glycerol uptake into human erythrocytes for a wide range of substrate concentrations and various temperatures. The experimental data quantitatively validated our theoretical-computational conclusions on the unsaturated glycerol transport through AQP3 that has high affinity for glycerol.
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Affiliation(s)
- Roberto A. Rodriguez
- Department of Physics, The University of Texas at San AntonioSan AntonioTexas 78249USA
| | - Ruth Chan
- Department of Physics, The University of Texas at San AntonioSan AntonioTexas 78249USA
| | - Huiyun Liang
- Department of Physics, The University of Texas at San AntonioSan AntonioTexas 78249USA
- Department of Pharmacology, The University of Texas Health Science Center at San AntonioSan AntonioTexas 78229USA
| | - Liao Y. Chen
- Department of Physics, The University of Texas at San AntonioSan AntonioTexas 78249USA
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Guo R, Wang L, Zeng X, Liu M, Zhou P, Lu H, Lin H, Dong M. Aquaporin 7 involved in GINSENOSIDE-RB1-mediated anti-obesity via peroxisome proliferator-activated receptor gamma pathway. Nutr Metab (Lond) 2020; 17:69. [PMID: 32821266 PMCID: PMC7433204 DOI: 10.1186/s12986-020-00490-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 08/06/2020] [Indexed: 12/22/2022] Open
Abstract
Background Obesity, characterized by the excessive accumulation of triglycerides in adipocytes and their decreased excretion from adipocytes, is closely related to various health problems. Ginsenoside Rb1 (Rb1), the most active component of the traditional Chinese medicine ginseng, has been reported to have positive effects on lipid metabolism. The aim of the present study was to determine the protective effects of Rb1 on glycolipid metabolism under obesity conditions and its mechanisms and to reveal the signaling pathways involved. Methods In our study, male C57BL/6 mice with obesity induced by a high-fat diet (HFD) and mature 3 T3-L1 adipocytes were used to investigate the role of Rb1 in lipid accumulation and explore its possible molecular mechanism in vivo and in vitro, respectively. Results Rb1 reduced the body weight, fat mass, adipocytes size and serum free fatty acid (FFA) concentration of obese mice. In differentiated 3 T3-L1 adipocytes, Rb1 reduced the accumulation of lipid droplets and stimulated output of triglycerides. Additionally, the expression of peroxisome proliferator-activated receptor gamma (PPARγ), phosphorylated PPARγ (Ser112) and aquaporin 7 (AQP7) was upregulated in adipocytes and adipose tissues upon Rb1 treatment. However, intervention of GW9662, PPARγ antagonist, attenuated Rb1-mediated effects on glycolipid metabolism and AQP7 levels. Conclusions These data indicated that Rb1 reduced body weight and improved glycolipid metabolism by upregulating PPARγ and AQP7 protein levels. Our study indicated a potential role for Rb1 in the prevention and treatment of obesity.
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Affiliation(s)
- Rong Guo
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, 107 Wenhuaxi Road, Jinan, 250012 China.,Department of Cardiology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, 362000 Fujian People's Republic of China.,Department of Cardiology, Ji'an Municipal Center People's Hospital, Ji'an, Jiangxi China
| | - Lei Wang
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, 107 Wenhuaxi Road, Jinan, 250012 China
| | - Xianqin Zeng
- Department of Cardiology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, 362000 Fujian People's Republic of China.,Department of Cardiology, Ji'an Municipal Center People's Hospital, Ji'an, Jiangxi China
| | - Minghao Liu
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, 107 Wenhuaxi Road, Jinan, 250012 China.,State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037 People's Republic of China
| | - Peng Zhou
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, 107 Wenhuaxi Road, Jinan, 250012 China
| | - Huixia Lu
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, 107 Wenhuaxi Road, Jinan, 250012 China
| | - Huili Lin
- Department of Cardiology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, 362000 Fujian People's Republic of China
| | - Mei Dong
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, 107 Wenhuaxi Road, Jinan, 250012 China
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8
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Expression, Distribution and Role of Aquaporins in Various Rhinologic Conditions. Int J Mol Sci 2020; 21:ijms21165853. [PMID: 32824013 PMCID: PMC7461600 DOI: 10.3390/ijms21165853] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 08/11/2020] [Accepted: 08/12/2020] [Indexed: 01/13/2023] Open
Abstract
Aquaporins (AQPs) are water-specific membrane channel proteins that regulate cellular and organismal water homeostasis. The nose, an organ with important respiratory and olfactory functions, is the first organ exposed to external stimuli. Nose-related topics such as allergic rhinitis (AR) and chronic rhinosinusitis (CRS) have been the subject of extensive research. These studies have reported that mechanisms that drive the development of multiple inflammatory diseases that occur in the nose and contribute to the process of olfactory recognition of compounds entering the nasal cavity involve the action of water channels such as AQPs. In this review, we provide a comprehensive overview of the relationship between AQPs and rhinologic conditions, focusing on the current state of knowledge and mechanisms that link AQPs and rhinologic conditions. Key conclusions include the following: (1) Various AQPs are expressed in both nasal mucosa and olfactory mucosa; (2) the expression of AQPs in these tissues is different in inflammatory diseases such as AR or CRS, as compared with that in normal tissues; (3) the expression of AQPs in CRS differs depending on the presence or absence of nasal polyps; and (4) the expression of AQPs in tissues associated with olfaction is different from that in the respiratory epithelium.
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de Maré SW, Venskutonytė R, Eltschkner S, de Groot BL, Lindkvist-Petersson K. Structural Basis for Glycerol Efflux and Selectivity of Human Aquaporin 7. Structure 2020; 28:215-222.e3. [DOI: 10.1016/j.str.2019.11.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 10/07/2019] [Accepted: 11/15/2019] [Indexed: 10/25/2022]
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10
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Liu L, Wu R, Zhang J, Li P. Overexpression of luxS Promotes Stress Resistance and Biofilm Formation of Lactobacillus paraplantarum L-ZS9 by Regulating the Expression of Multiple Genes. Front Microbiol 2018; 9:2628. [PMID: 30483223 PMCID: PMC6240686 DOI: 10.3389/fmicb.2018.02628] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 10/15/2018] [Indexed: 12/14/2022] Open
Abstract
Probiotics have evoked great interest in the past years for their beneficial effects. The aim of this study was to investigate whether luxS overexpression promotes the stress resistance of Lactobacillus paraplantarum L-ZS9. Here we show that overexpression of luxS gene increased the production of autoinducer-2 (AI-2, quorum sensing signal molecule) by L. paraplantarum L-ZS9. At the same time, overexpression of luxS promoted heat-, bile salt-resistance and biofilm formation of the strain. RNAseq results indicated that multiple genes encoding transporters, membrane proteins, and transcriptional regulator were regulated by luxS. These results reveal a new role for LuxS in promoting stress resistance and biofilm formation of probiotic starter.
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Affiliation(s)
- Lei Liu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China.,Key Laboratory of Functional Dairy, China Agricultural University, Beijing, China
| | - Ruiyun Wu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China.,Key Laboratory of Functional Dairy, China Agricultural University, Beijing, China
| | - Jinlan Zhang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China.,Key Laboratory of Functional Dairy, China Agricultural University, Beijing, China
| | - Pinglan Li
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China.,Key Laboratory of Functional Dairy, China Agricultural University, Beijing, China
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11
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Molecular Basis of Aquaporin-7 Permeability Regulation by pH. Cells 2018; 7:cells7110207. [PMID: 30423801 PMCID: PMC6262577 DOI: 10.3390/cells7110207] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Revised: 11/05/2018] [Accepted: 11/07/2018] [Indexed: 01/09/2023] Open
Abstract
The aquaglyceroporin AQP7, a family member of aquaporin membrane channels, facilitates the permeation of water and glycerol through cell membranes and is crucial for body lipid and energy homeostasis. Regulation of glycerol permeability via AQP7 is considered a promising therapeutic strategy towards fat-related metabolic complications. Here, we used a yeast aqy-null strain for heterologous expression and functional analysis of human AQP7 and investigated its regulation by pH. Using a combination of in vitro and in silico approaches, we found that AQP7 changes from fully permeable to virtually closed at acidic pH, and that Tyr135 and His165 facing the extracellular environment are crucial residues for channel permeability. Moreover, instead of reducing the pore size, the protonation of key residues changes AQP7’s protein surface electrostatic charges, which, in turn, may decrease glycerol’s binding affinity to the pore, resulting in decreased permeability. In addition, since some pH-sensitive residues are located at the monomer-monomer interface, decreased permeability may result from cooperativity between AQP7’s monomers. Considering the importance of glycerol permeation via AQP7 in multiple pathophysiological conditions, this mechanism of hAQP7 pH-regulation may help the design of selective modulators targeting aquaglyceroporin-related disorders.
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12
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A Review: Expression of Aquaporins in Otitis Media. Int J Mol Sci 2017; 18:ijms18102164. [PMID: 29039751 PMCID: PMC5666845 DOI: 10.3390/ijms18102164] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 10/11/2017] [Accepted: 10/11/2017] [Indexed: 12/20/2022] Open
Abstract
Otitis media (OM) refers to inflammatory diseases of the middle ear (ME), regardless of cause or pathological mechanism. Among the molecular biological studies assessing the pathology of OM are investigations of the expression of aquaporins (AQPs) in the ME and Eustachian tube (ET). To date, fifteen studies have evaluated AQPs expression in the ME and ET. Although the expression of individual AQPs varies by species and model, eleven types of AQP, AQP1 to AQP11, were found to be expressed in mammalian ME and ET. The review showed that: (1) various types of AQPs are expressed in the ME and ET; (2) AQP expression may vary by species; and (3) the distribution and levels of expression of AQPs may depend on the presence or absence of inflammation, with variations even in the same species and same tissue. Fluid accumulation in the ME and ET is a common pathological mechanism for all types of OM, causing edema in the tissue and inducing inflammation, thereby possibly involving various AQPs. The expression patterns of several AQPs, especially AQP1, 4 and 5, were found to be altered in response to inflammatory stimuli, including lipopolysaccharide (LPS), suggesting that AQPs may have immunological functions in OM.
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13
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Crisóstomo L, Alves MG, Calamita G, Sousa M, Oliveira PF. Glycerol and testicular activity: the good, the bad and the ugly. Mol Hum Reprod 2017; 23:725-737. [DOI: 10.1093/molehr/gax049] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 09/05/2017] [Indexed: 12/17/2022] Open
Affiliation(s)
- Luís Crisóstomo
- Department of Microscopy, Laboratory of Cell Biology, and Unit for Multidisciplinary Research in Biomedicine (UMIB), Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
- Department of Genetics, Faculty of Medicine, University of Porto, Porto, Portugal
- i3S—Instituto de Investigação e Inovação em Saúde, University of Porto, Porto, Portugal
| | - Marco G Alves
- Department of Microscopy, Laboratory of Cell Biology, and Unit for Multidisciplinary Research in Biomedicine (UMIB), Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
| | - Giuseppe Calamita
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari ‘Aldo Moro’, Bari, Italy
| | - Mário Sousa
- Department of Microscopy, Laboratory of Cell Biology, and Unit for Multidisciplinary Research in Biomedicine (UMIB), Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
- Centre for Reproductive Genetics Professor Alberto Barros, Porto, Portugal
| | - Pedro F Oliveira
- Department of Microscopy, Laboratory of Cell Biology, and Unit for Multidisciplinary Research in Biomedicine (UMIB), Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
- Department of Genetics, Faculty of Medicine, University of Porto, Porto, Portugal
- i3S—Instituto de Investigação e Inovação em Saúde, University of Porto, Porto, Portugal
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari ‘Aldo Moro’, Bari, Italy
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14
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Katano T, Ito Y, Ohta K, Yasujima T, Inoue K, Yuasa H. Competitive Inhibition of AQP7-mediated Glycerol Transport by Glycerol Derivatives. Drug Metab Pharmacokinet 2014; 29:348-51. [DOI: 10.2133/dmpk.dmpk-13-nt-139] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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