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MacDonald E, Johannes L, Wunder C. Acidification on the plasma membrane. Curr Opin Cell Biol 2025; 95:102531. [PMID: 40378645 DOI: 10.1016/j.ceb.2025.102531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2025] [Revised: 04/17/2025] [Accepted: 04/21/2025] [Indexed: 05/19/2025]
Abstract
The pH balance between extracellular and intracellular space is crucial for a multitude of cellular processes. Real-time observation of pH fluctuations in the range 4-9 in live cells and tissues in a sensitive, non-invasive manner has become feasible with advances in pH quantification by organic dyes, genetically encoded fluorescent proteins, and DNA-based probes. We discuss mechanisms through which pH affects cell cycle, transcription, senescence, neurotransmission, glycolipid-lectin driven endocytosis, tissue remodelling, immune responses, and GPCR signalling. Growth factor-stimulated acidification of the extracellular space notably triggers enzymatic reactions like desialylation at the plasma membrane that control processes involving cell migration and bone resorption. Research into the role of pH in cellular physiology continues to be a fertile ground for discovery that underscores its fundamental importance.
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Affiliation(s)
- Ewan MacDonald
- Montpellier Cell Biology Research Center, CRBM, Université 40 Montpellier, CNRS, Montpellier, France.
| | - Ludger Johannes
- Institut Curie, PSL Research University, U1339 INSERM, UMR3666 CNRS, Chemical Biology of Cancer Unit, Paris, France; Inria Center at University of Rennes, SAIRPICO Team, U1339 INSERM, Institut Curie, Chemical Biology of Cancer Unit, Paris, France.
| | - Christian Wunder
- Institut Curie, PSL Research University, U1339 INSERM, UMR3666 CNRS, Chemical Biology of Cancer Unit, Paris, France; Inria Center at University of Rennes, SAIRPICO Team, U1339 INSERM, Institut Curie, Chemical Biology of Cancer Unit, Paris, France.
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2
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Runyan LA, Kudryashova E, Agrawal R, Mohamed M, Kudryashov DS. Human plastins are novel cytoskeletal pH sensors with a reduced F-actin bundling capacity at basic pH. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2025.03.26.645573. [PMID: 40196613 PMCID: PMC11974883 DOI: 10.1101/2025.03.26.645573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 04/09/2025]
Abstract
Intracellular pH (pHi) is a fundamental component of cell homeostasis. Controlled elevations in pHi precede and accompany cell polarization, cytokinesis, and directional migration. pH dysregulation contributes to cancer, neurodegenerative diseases, diabetes, and other metabolic disorders. While cytoskeletal rearrangements are crucial for these processes, only a few cytoskeletal proteins, namely Cdc42, cofilin, talin, cortactin, α-actinin, and AIP1 have been documented as pH sensors. Here, we report that actin-bundling proteins plastin 2 (PLS2, aka LCP1) and plastin 3 (PLS3) respond to physiological scale pH fluctuations by a reduced F-actin bundling at alkaline pH. The inhibition of PLS2 actin-bundling activity at elevated pH stems from the reduced affinity of the N-terminal actin-binding domain (ABD1) to actin. In fibroblast cells, elevated cytosolic pH caused the dissociation of ectopically expressed PLS2 from actin structures, whereas acidic conditions promoted its tighter association with focal adhesions and stress fibers. We identified His207 as one of the pH-sensing residues whose mutation to Lys and Tyr reduces pH sensitivity by enhancing and inhibiting the bundling ability, respectively. Our results suggest that weaker actin bundling by plastin isoforms at alkaline pH favors higher dynamics of the actin cytoskeleton. Therefore, like other cytoskeleton pH sensors, plastins promote disassembly and faster dynamics of cytoskeletal components during cytokinesis and cell migration. Since both plastins are implemented in cancer, their pH sensitivity may contribute to the accelerated proliferation and enhanced invasive and metastatic potentials of cancer cells at alkaline pHi.
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Affiliation(s)
- Lucas A. Runyan
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA, 43210
| | - Elena Kudryashova
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA, 43210
| | - Richa Agrawal
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA, 43210
| | - Mubarik Mohamed
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA, 43210
| | - Dmitri S. Kudryashov
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA, 43210
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3
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Baig F, Bakdaleyeh M, Bazzi HM, Cao L, Tripathy SK. Dissecting the pH Sensitivity of Kinesin-Driven Transport. J Phys Chem B 2024; 128:11855-11864. [PMID: 39575923 PMCID: PMC11627161 DOI: 10.1021/acs.jpcb.4c03850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2024] [Revised: 10/11/2024] [Accepted: 10/23/2024] [Indexed: 12/06/2024]
Abstract
Kinesin-1 is a crucial motor protein that drives the microtubule-based movement of organelles, vital for cellular function and health. Mostly studied at pH 6.9, it moves at approximately 800 nm/s, covers about 1 μm before detaching, and hydrolyzes one ATP per 8 nm step. Given that cellular pH is dynamic and alterations in pH have significant implications for disease, understanding how kinesin-1 functions across different pH levels is crucial. To explore this, we executed single-molecule motility assays paired with precise optical trapping techniques over a pH range of 5.5-9.8. Our results show a consistent positive relationship between increasing pH and the enhanced detachment (off rate) and speed of kinesin-1. Measurements of the nucleotide-dependent off rate show that kinesin-1 exhibits the highest rate of ATPase activity at alkaline pH, while it demonstrates the optimal number of ATP turnover and cargo translocation efficiency at the acidic pH. Physiological pH of 6.9 optimally balances the biophysical activity of kinesin-1, potentially allowing it to function effectively across a range of pH levels. These insights emphasize the crucial role of pH homeostasis in cellular function, highlighting its importance for the precise regulation of motor proteins and efficient intracellular transport.
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Affiliation(s)
- Fawaz Baig
- Department of Natural Sciences, University of Michigan-Dearborn, 4901 Evergreen Road, Dearborn, Michigan 48128, United States
| | - Michael Bakdaleyeh
- Department of Natural Sciences, University of Michigan-Dearborn, 4901 Evergreen Road, Dearborn, Michigan 48128, United States
| | - Hassan M. Bazzi
- Department of Natural Sciences, University of Michigan-Dearborn, 4901 Evergreen Road, Dearborn, Michigan 48128, United States
| | - Lanqin Cao
- Department of Natural Sciences, University of Michigan-Dearborn, 4901 Evergreen Road, Dearborn, Michigan 48128, United States
| | - Suvranta K. Tripathy
- Department of Natural Sciences, University of Michigan-Dearborn, 4901 Evergreen Road, Dearborn, Michigan 48128, United States
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Romero-Moreno R, Czowski BJ, Harris L, Kuehn JF, White KA. Intracellular pH differentially regulates transcription of metabolic and signaling pathways in normal epithelial cells. J Biol Chem 2024; 300:107658. [PMID: 39128712 PMCID: PMC11489351 DOI: 10.1016/j.jbc.2024.107658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2024] [Accepted: 07/31/2024] [Indexed: 08/13/2024] Open
Abstract
Intracellular pH (pHi) dynamics regulate normal cell function, and dysregulated pHi dynamics is an emerging hallmark of cancer (constitutively increased pHi) and neurodegeneration (constitutively decreased pHi). However, the molecular mechanisms by which pHi dynamics regulate cell biology are poorly understood. Here, we discovered that altering pHi in normal human breast epithelial cells triggers global transcriptional changes. We identified 176 genes differentially regulated by pHi, with pHi-dependent genes clustering in signaling and glycolytic pathways. Using various normal epithelial cell models, we showed pH-dependent Notch homolog 1 protein expression, with increased protein abundance at high pHi. This resulted in pH-dependent downstream signaling, with increased Notch homolog 1 signaling at high pHi. We also found that high pHi increased the expression of glycolytic enzymes and regulators of pyruvate fate, including lactate dehydrogenase and pyruvate dehydrogenase kinase. These transcriptional changes were sufficient to alter lactate production, with high pHi shifting these normal epithelial cells toward a glycolytic metabolism and increasing lactate production. Thus, pHi dynamics transcriptionally regulate signaling and metabolic pathways in normal epithelial cells. Our data reveal new molecular regulators of pHi-dependent biology and a role for increased pHi in driving the acquisition of cancer-associated signaling and metabolic changes in normal human epithelial cells.
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Affiliation(s)
- Ricardo Romero-Moreno
- Harper Cancer Research Institute, South Bend, Indiana, USA; Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Brandon J Czowski
- Harper Cancer Research Institute, South Bend, Indiana, USA; Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Lindsey Harris
- Harper Cancer Research Institute, South Bend, Indiana, USA; Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Jessamine F Kuehn
- Harper Cancer Research Institute, South Bend, Indiana, USA; Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Katharine A White
- Harper Cancer Research Institute, South Bend, Indiana, USA; Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA.
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Van Dyck PK, Piszkin L, Gorski EA, Nascimento ET, Abebe JA, Hoffmann LM, Peng JW, White KA. Ionizable networks mediate pH-dependent allostery in SH2 signaling proteins. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.21.608875. [PMID: 39229188 PMCID: PMC11370553 DOI: 10.1101/2024.08.21.608875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 09/05/2024]
Abstract
IntroductionTransient intracellular pH dynamics1regulate mammalian proliferation2,3, migration4, and differentiation5. However, for many pH-dependent cell processes, the molecular mediators are unknown6. Prior work identified histidine residues as molecular switches in pH-sensitive proteins, but how other ionizable residues contribute to pH-dependent protein allostery is understudied. Here, we develop anin silicocomputational pipeline to identify putative pH-sensitive proteins and their molecular mechanisms. We first apply this pipeline to SHP2, a known pH-sensitive signaling protein with an uncharacterized molecular mechanism. We show wild-type SHP2 phosphatase activity is pH-sensitivein vitroand in cells, and mutation of identified H116 and E252 to non-titratable alanine residues abolishes pH-sensitive function. We also show that c-Src is a previously unrecognized pH-dependent kinase, and mutation of the identified ionizable network again abolishes pH-sensitive activity. Constant pH molecular dynamics simulations support a conserved allosteric mechanism of pH-dependent binding of inhibitory SH2 domains to the functional catalytic domains of SHP2 and c-Src. We apply our computational pipeline across SH2 domain-containing signaling proteins and identify evolutionarily conserved putative pH-sensing networks. Our results reveal that pH is an allosteric regulator of SH2 domain-containing signaling proteins providing insight into normal pH-dependent cell biology and diseases where pHi is dysregulated, such as cancer.
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Affiliation(s)
- Papa Kobina Van Dyck
- Department of Chemistry and Biochemistry, University of Notre Dame 251 Nieuwland Science Hall Notre Dame, IN 46556 USA
- Harper Cancer Research Institute, University of Notre Dame 1234 N. Notre Dame Avenue South Bend, IN 46617 USA
| | - Luke Piszkin
- Department of Chemistry and Biochemistry, University of Notre Dame 251 Nieuwland Science Hall Notre Dame, IN 46556 USA
| | - Elijah A. Gorski
- Department of Chemistry and Biochemistry, University of Notre Dame 251 Nieuwland Science Hall Notre Dame, IN 46556 USA
- Harper Cancer Research Institute, University of Notre Dame 1234 N. Notre Dame Avenue South Bend, IN 46617 USA
| | - Eduarda Tartarella Nascimento
- Department of Chemistry and Biochemistry, University of Notre Dame 251 Nieuwland Science Hall Notre Dame, IN 46556 USA
- Harper Cancer Research Institute, University of Notre Dame 1234 N. Notre Dame Avenue South Bend, IN 46617 USA
- Saint Mary’s College, Notre Dame, IN 46556 USA
| | - Joshua A. Abebe
- Department of Chemistry and Biochemistry, University of Notre Dame 251 Nieuwland Science Hall Notre Dame, IN 46556 USA
- Harper Cancer Research Institute, University of Notre Dame 1234 N. Notre Dame Avenue South Bend, IN 46617 USA
| | - Logan M. Hoffmann
- Department of Chemistry and Biochemistry, University of Notre Dame 251 Nieuwland Science Hall Notre Dame, IN 46556 USA
- Harper Cancer Research Institute, University of Notre Dame 1234 N. Notre Dame Avenue South Bend, IN 46617 USA
| | - Jeffrey W. Peng
- Department of Chemistry and Biochemistry, University of Notre Dame 251 Nieuwland Science Hall Notre Dame, IN 46556 USA
| | - Katharine A. White
- Department of Chemistry and Biochemistry, University of Notre Dame 251 Nieuwland Science Hall Notre Dame, IN 46556 USA
- Harper Cancer Research Institute, University of Notre Dame 1234 N. Notre Dame Avenue South Bend, IN 46617 USA
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6
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Didan Y, Ghomlaghi M, Nguyen LK, Ng DCH. Stress pathway outputs are encoded by pH-dependent clustering of kinase components. Nat Commun 2024; 15:6614. [PMID: 39103333 DOI: 10.1038/s41467-024-50638-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Accepted: 07/10/2024] [Indexed: 08/07/2024] Open
Abstract
Signal processing by intracellular kinases controls near all biological processes but how signal pathway functions evolve with changed cellular context is poorly understood. Functional specificity of c-Jun N-terminal Kinases (JNK) are partly encoded by signal strength. Here we reveal that intracellular pH (pHi) is a significant component of the JNK network and defines signal response to specific stimuli. We show pHi regulates JNK activity in response to cell stress, with the relationship between pHi and JNK activity dependent on specific stimuli and upstream kinases activated. Using the optogenetic clustering tag CRY2, we show that an increase in pHi promotes the light-induced phase transition of ASK1 to augment JNK activation. While increased pHi similarly promoted CRY2-tagged JNK2 to form light-induced condensates, this attenuated JNK activity. Mathematical modelling of feedback signalling incorporating pHi and differential contributions by ASK1 and JNK2 condensates was sufficient to delineate signal responses to specific stimuli. Taking pHi and ASK1/JNK2 signal contributions into consideration may delineate oncogenic versus tumour suppressive JNK functions and cancer cell drug responses.
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Affiliation(s)
- Yuliia Didan
- School of Biomedical Science, Faculty of Medicine, University of Queensland; St Lucia, Brisbane, Australia
| | - Milad Ghomlaghi
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Australia
- Biomedicine Discovery Institute, Monash University, Clayton, Australia
| | - Lan K Nguyen
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Australia
- Biomedicine Discovery Institute, Monash University, Clayton, Australia
| | - Dominic C H Ng
- School of Biomedical Science, Faculty of Medicine, University of Queensland; St Lucia, Brisbane, Australia.
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7
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Wilson CJ, de Groot BL, Gapsys V. Resolving coupled pH titrations using alchemical free energy calculations. J Comput Chem 2024; 45:1444-1455. [PMID: 38471815 DOI: 10.1002/jcc.27318] [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: 09/17/2023] [Revised: 01/11/2024] [Accepted: 01/16/2024] [Indexed: 03/14/2024]
Abstract
In a protein, nearby titratable sites can be coupled: the (de)protonation of one may affect the other. The degree of this interaction depends on several factors and can influence the measured p K a . Here, we derive a formalism based on double free energy differences ( Δ Δ G ) for quantifying the individual site p K a values of coupled residues. As Δ Δ G values can be obtained by means of alchemical free energy calculations, the presented approach allows for a convenient estimation of coupled residue p K a s in practice. We demonstrate that our approach and a previously proposed microscopic p K a formalism, can be combined with alchemical free energy calculations to resolve pH-dependent protein p K a values. Toy models and both, regular and constant-pH molecular dynamics simulations, alongside experimental data, are used to validate this approach. Our results highlight the insights gleaned when coupling and microstate probabilities are analyzed and suggest extensions to more complex enzymatic contexts. Furthermore, we find that naïvely computed p K a values that ignore coupling, can be significantly improved when coupling is accounted for, in some cases reducing the error by half. In short, alchemical free energy methods can resolve the p K a values of both uncoupled and coupled residues.
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Affiliation(s)
- Carter J Wilson
- Department of Mathematics, The University of Western Ontario, London, Ontario, Canada
- Centre for Advanced Materials and Biomaterials Research (CAMBR), The University of Western Ontario, London, Ontario, Canada
- Computational Biomolecular Dynamics Group, Department of Theoretical and Computational Biophysics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Bert L de Groot
- Computational Biomolecular Dynamics Group, Department of Theoretical and Computational Biophysics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Vytautas Gapsys
- Computational Biomolecular Dynamics Group, Department of Theoretical and Computational Biophysics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Computational Chemistry, Janssen Research & Development, Beerse, Belgium
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8
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Jiang M, Salari A, Stock C, Nikolovska K, Boedtkjer E, Amiri M, Seidler UE. The electroneutral Na +-HCO 3- cotransporter NBCn1 (SLC4A7) modulates colonic enterocyte pH i, proliferation, and migration. Am J Physiol Cell Physiol 2024; 326:C1625-C1636. [PMID: 38646790 PMCID: PMC11371319 DOI: 10.1152/ajpcell.00079.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 04/05/2024] [Accepted: 04/06/2024] [Indexed: 04/23/2024]
Abstract
NBCn1 (SLC4A7) is one of the two major Na+-HCO3- cotransporters in the human colonic epithelium, expressed predominantly in the highly proliferating colonocytes at the cryptal base. Increased NBCn1 expression levels are reported in tumors, including colorectal cancer. The study explores its importance for maintenance of the intracellular pH (pHi), as well as the proliferative, adhesive, and migratory behavior of the self-differentiating Caco2BBe colonic tumor cell line. In the self-differentiating Caco2BBe cells, NBCn1 mRNA was highly expressed from the proliferative stage until full differentiation. The downregulation of NBCn1 expression by RNA interference affected proliferation and differentiation and decreased intracellular pH (pHi) of the cells in correlation with the degree of knockdown. In addition, a disturbed cell adhesion and reduced migratory speed were associated with NBCn1 knockdown. Murine colonic Nbcn1-/- enteroids also displayed reduced proliferative activity. In the migrating Caco2BBe cells, NBCn1 was found at the leading edge and in colocalization with the focal adhesion markers vinculin and paxillin, which suggests that NBCn1 is involved in the establishment of cell-matrix adhesion. Our data highlight the physiological significance of NBCn1 in modulating epithelial pH homeostasis and cell-matrix interactions in the proliferative region of the colonic epithelium and unravel the molecular mechanism behind pathological overexpression of this transporter in human colorectal cancers.NEW & NOTEWORTHY The transporter NBCn1 plays a central role in maintaining homeostasis within Caco2BBe colonic epithelial cells through its regulation of intracellular pH, matrix adhesion, migration, and proliferation. These observations yield valuable insights into the molecular mechanism of the aberrant upregulation of this transporter in human colorectal cancers.
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Affiliation(s)
- Min Jiang
- Department of Gastroenterology, Hepatology, Infectious Diseases and Endocrinology, Hannover Medical School, Hannover, Germany
| | - Azam Salari
- Department of Gastroenterology, Hepatology, Infectious Diseases and Endocrinology, Hannover Medical School, Hannover, Germany
| | - Christian Stock
- Department of Gastroenterology, Hepatology, Infectious Diseases and Endocrinology, Hannover Medical School, Hannover, Germany
| | - Katerina Nikolovska
- Department of Gastroenterology, Hepatology, Infectious Diseases and Endocrinology, Hannover Medical School, Hannover, Germany
| | - Ebbe Boedtkjer
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Mahdi Amiri
- Department of Gastroenterology, Hepatology, Infectious Diseases and Endocrinology, Hannover Medical School, Hannover, Germany
| | - Ursula E Seidler
- Department of Gastroenterology, Hepatology, Infectious Diseases and Endocrinology, Hannover Medical School, Hannover, Germany
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Kisor KP, Ruiz DG, Jacobson MP, Barber DL. A role for pH dynamics regulating transcription factor DNA binding selectivity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.21.595212. [PMID: 38826444 PMCID: PMC11142074 DOI: 10.1101/2024.05.21.595212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Intracellular pH (pHi) dynamics regulates diverse cell processes such as proliferation, dysplasia, and differentiation, often mediated by the protonation state of a functionally critical histidine residue in endogenous pH sensing proteins. How pHi dynamics can directly regulate gene expression and whether transcription factors can function as pH sensors has received limited attention. We tested the prediction that transcription factors with a histidine in their DNA binding domain (DBD) that forms hydrogen bonds with nucleotides can have pH-regulated activity, which is relevant to more than 85 transcription factors in distinct families, including FOX, KLF, SOX and MITF/Myc. Focusing on FOX family transcription factors, we used unbiased SELEX-seq to identify pH-dependent DNA binding motif preferences, then confirm pH-regulated binding affinities for FOXC2, FOXM1, and FOXN1 to a canonical FkhP DNA motif that are 2.5 to 7.5 greater at pH 7.0 compared with pH 7.5. For FOXC2, we also find greater activity for an FkhP motif at lower pHi in cells and that pH-regulated binding and activity are dependent on a conserved histidine (His122) in the DBD. RNA-seq with FOXC2 also reveals pH-dependent differences in enriched promoter motifs. Our findings identify pH-regulated transcription factor-DNA binding selectivity with relevance to how pHi dynamics can regulate gene expression for myriad cell behaviours.
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10
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Zimmerman SG, Berg CA. CO2 exposure drives a rapid pH response in live adult Drosophila. PLoS One 2024; 19:e0302240. [PMID: 38625910 PMCID: PMC11020609 DOI: 10.1371/journal.pone.0302240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 03/29/2024] [Indexed: 04/18/2024] Open
Abstract
CO2 anesthesia is the most common method for immobilizing Drosophila for research purposes. But CO2 exposure has consequences-it can impact fertility, behavior, morphogenesis, and cytoskeletal dynamics. In this respect, Drosophila is an outstanding model for studying the impact of CO2 exposure on tissues. In this study we explored the response of intracellular pH (pHi) to a one-minute CO2 pulse using a genetically encoded, ubiquitously expressed pH sensor, tpHusion, to monitor pHi within a live, intact, whole fly. We compared wild-type flies to flies lacking Imaginal disc growth factors (Idgfs), which are chitinase-like proteins that facilitate developmental processes and the innate immune response. Morphogenetic and cytoskeletal defects in Idgf-null flies are enhanced after CO2 exposure. We found that pHi drops sharply within seconds of the beginning of a CO2 pulse and recovers over several minutes. The initial profile was nearly identical in control and Idgf-null flies but diverged as the pHi returned to normal. This study demonstrates the feasibility of monitoring pH in live adult Drosophila. Studies exploring pH homeostasis are important for understanding human pathologies associated with pH dysregulation.
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Affiliation(s)
- Sandra G. Zimmerman
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Celeste A. Berg
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
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11
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Stock C. pH-regulated single cell migration. Pflugers Arch 2024; 476:639-658. [PMID: 38214759 PMCID: PMC11006768 DOI: 10.1007/s00424-024-02907-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 12/21/2023] [Accepted: 01/02/2024] [Indexed: 01/13/2024]
Abstract
Over the last two decades, extra- and intracellular pH have emerged as fundamental regulators of cell motility. Fundamental physiological and pathological processes relying on appropriate cell migration, such as embryonic development, wound healing, and a proper immune defense on the one hand, and autoimmune diseases, metastatic cancer, and the progression of certain parasitic diseases on the other, depend on surrounding pH. In addition, migrating single cells create their own localized pH nanodomains at their surface and in the cytosol. By this means, the migrating cells locally modulate their adhesion to, and the re-arrangement and digestion of, the extracellular matrix. At the same time, the cytosolic nanodomains tune cytoskeletal dynamics along the direction of movement resulting in concerted lamellipodia protrusion and rear end retraction. Extracellular pH gradients as found in wounds, inflamed tissues, or the periphery of tumors stimulate directed cell migration, and long-term exposure to acidic conditions can engender a more migratory and invasive phenotype persisting for hours up to several generations of cells after they have left the acidic milieu. In the present review, the different variants of pH-dependent single cell migration are described. The underlying pH-dependent molecular mechanisms such as conformational changes of adhesion molecules, matrix protease activity, actin (de-)polymerization, and signaling events are explained, and molecular pH sensors stimulated by H+ signaling are presented.
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Affiliation(s)
- Christian Stock
- Department of Gastroenterology, Hepatology, Infectiology & Endocrinology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
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12
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Pedersen SHF. Acid-base transporters in the context of tumor heterogeneity. Pflugers Arch 2024; 476:689-701. [PMID: 38332178 DOI: 10.1007/s00424-024-02918-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 01/20/2024] [Accepted: 01/29/2024] [Indexed: 02/10/2024]
Abstract
The copious metabolic acid production and -extrusion by cancer cells render poorly vascularized regions of solid tumors highly acidic. A growing list of proton - and bicarbonate transporters has been suggested to contribute to net acid extrusion from cancer cells, and/or been shown to be dysregulated and favor malignant development in various cancers. The great majority of these roles have been studied at the level of the cancer cells. However, recent advances in understanding of the cellular and physicochemical heterogeneity of solid tumors both enable and necessitate a reexamination of the regulation and roles of acid-base transporters in such malignancies. This review will briefly summarize the state-of-the-art, with a focus on the SLC9A and SLC4A families, for which most evidence is available. This is followed by a discussion of key concepts and open questions arising from recent insights and of the challenges that need to be tackled to address them. Finally, opportunities and challenges in therapeutic targeting of the acid-base transportome in cancers will be addressed.
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Affiliation(s)
- Stine Helene Falsig Pedersen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Universitetsparken 13, 2100, Copenhagen, Denmark.
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13
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Michl J, White B, Monterisi S, Bodmer WF, Swietach P. Phenotypic screen of sixty-eight colorectal cancer cell lines identifies CEACAM6 and CEACAM5 as markers of acid resistance. Proc Natl Acad Sci U S A 2024; 121:e2319055121. [PMID: 38502695 PMCID: PMC10990159 DOI: 10.1073/pnas.2319055121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 02/13/2024] [Indexed: 03/21/2024] Open
Abstract
Elevated cancer metabolism releases lactic acid and CO2 into the under-perfused tumor microenvironment, resulting in extracellular acidosis. The surviving cancer cells must adapt to this selection pressure; thus, targeting tumor acidosis is a rational therapeutic strategy to manage tumor growth. However, none of the major approved treatments are based explicitly on disrupting acid handling, signaling, or adaptations, possibly because the distinction between acid-sensitive and acid-resistant phenotypes is not clear. Here, we report pH-related phenotypes of sixty-eight colorectal cancer (CRC) cell lines by measuring i) extracellular acidification as a readout of acid production by fermentative metabolism and ii) growth of cell biomass over a range of extracellular pH (pHe) levels as a measure of the acid sensitivity of proliferation. Based on these measurements, CRC cell lines were grouped along two dimensions as "acid-sensitive"/"acid-resistant" versus "low metabolic acid production"/"high metabolic acid production." Strikingly, acid resistance was associated with the expression of CEACAM6 and CEACAM5 genes coding for two related cell-adhesion molecules, and among pH-regulating genes, of CA12. CEACAM5/6 protein levels were strongly induced by acidity, with a further induction under hypoxia in a subset of CRC lines. Lack of CEACAM6 (but not of CEACAM5) reduced cell growth and their ability to differentiate. Finally, CEACAM6 levels were strongly increased in human colorectal cancers from stage II and III patients, compared to matched samples from adjacent normal tissues. Thus, CEACAM6 is a marker of acid-resistant clones in colorectal cancer and a potential motif for targeting therapies to acidic regions within the tumors.
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Affiliation(s)
- Johanna Michl
- Department of Physiology, Anatomy and Genetics, University of Oxford, OxfordOX1 3PT, United Kingdom
| | - Bobby White
- Department of Physiology, Anatomy and Genetics, University of Oxford, OxfordOX1 3PT, United Kingdom
| | - Stefania Monterisi
- Department of Physiology, Anatomy and Genetics, University of Oxford, OxfordOX1 3PT, United Kingdom
| | - Walter F. Bodmer
- Department of Oncology, University of Oxford, OxfordOX3 7DQ, United Kingdom
| | - Pawel Swietach
- Department of Physiology, Anatomy and Genetics, University of Oxford, OxfordOX1 3PT, United Kingdom
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14
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Shehjar F, Almarghalani DA, Mahajan R, Hasan SAM, Shah ZA. The Multifaceted Role of Cofilin in Neurodegeneration and Stroke: Insights into Pathogenesis and Targeting as a Therapy. Cells 2024; 13:188. [PMID: 38247879 PMCID: PMC10814918 DOI: 10.3390/cells13020188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 01/03/2024] [Accepted: 01/10/2024] [Indexed: 01/23/2024] Open
Abstract
This comprehensive review explores the complex role of cofilin, an actin-binding protein, across various neurodegenerative diseases (Alzheimer's, Parkinson's, schizophrenia, amyotrophic lateral sclerosis (ALS), Huntington's) and stroke. Cofilin is an essential protein in cytoskeletal dynamics, and any dysregulation could lead to potentially serious complications. Cofilin's involvement is underscored by its impact on pathological hallmarks like Aβ plaques and α-synuclein aggregates, triggering synaptic dysfunction, dendritic spine loss, and impaired neuronal plasticity, leading to cognitive decline. In Parkinson's disease, cofilin collaborates with α-synuclein, exacerbating neurotoxicity and impairing mitochondrial and axonal function. ALS and frontotemporal dementia showcase cofilin's association with genetic factors like C9ORF72, affecting actin dynamics and contributing to neurotoxicity. Huntington's disease brings cofilin into focus by impairing microglial migration and influencing synaptic plasticity through AMPA receptor regulation. Alzheimer's, Parkinson's, and schizophrenia exhibit 14-3-3 proteins in cofilin dysregulation as a shared pathological mechanism. In the case of stroke, cofilin takes center stage, mediating neurotoxicity and neuronal cell death. Notably, there is a potential overlap in the pathologies and involvement of cofilin in various diseases. In this context, referencing cofilin dysfunction could provide valuable insights into the common pathologies associated with the aforementioned conditions. Moreover, this review explores promising therapeutic interventions, including cofilin inhibitors and gene therapy, demonstrating efficacy in preclinical models. Challenges in inhibitor development, brain delivery, tissue/cell specificity, and long-term safety are acknowledged, emphasizing the need for precision drug therapy. The call to action involves collaborative research, biomarker identification, and advancing translational efforts. Cofilin emerges as a pivotal player, offering potential as a therapeutic target. However, unraveling its complexities requires concerted multidisciplinary efforts for nuanced and effective interventions across the intricate landscape of neurodegenerative diseases and stroke, presenting a hopeful avenue for improved patient care.
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Affiliation(s)
- Faheem Shehjar
- Department of Medicinal and Biological Chemistry, College of Pharmacy and Pharmaceutical Sciences, Toledo, OH 43614, USA; (F.S.); (R.M.)
| | - Daniyah A. Almarghalani
- Stroke Research Unit, Department of Pharmacology and Toxicology, College of Pharmacy, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia;
| | - Reetika Mahajan
- Department of Medicinal and Biological Chemistry, College of Pharmacy and Pharmaceutical Sciences, Toledo, OH 43614, USA; (F.S.); (R.M.)
| | - Syed A.-M. Hasan
- Department of Pharmacology and Experimental Therapeutics, College of Pharmacy and Pharmaceutical Sciences, University of Toledo, Toledo, OH 43614, USA;
| | - Zahoor A. Shah
- Department of Medicinal and Biological Chemistry, College of Pharmacy and Pharmaceutical Sciences, Toledo, OH 43614, USA; (F.S.); (R.M.)
- Department of Pharmacology and Experimental Therapeutics, College of Pharmacy and Pharmaceutical Sciences, University of Toledo, Toledo, OH 43614, USA;
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15
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余 哲, 姬 彦, 黄 文, 方 颖, 吴 建. [Molecular dynamics simulation of force-regulated interaction between talin and Rap1b]. SHENG WU YI XUE GONG CHENG XUE ZA ZHI = JOURNAL OF BIOMEDICAL ENGINEERING = SHENGWU YIXUE GONGCHENGXUE ZAZHI 2023; 40:645-653. [PMID: 37666754 PMCID: PMC10477389 DOI: 10.7507/1001-5515.202208022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 12/22/2022] [Indexed: 09/06/2023]
Abstract
The binding of talin-F0 domain to ras-related protein 1b (Rap1b) plays an important role in the formation of thrombosis. However, since talin is a force-sensitive protein, it remains unclear whether and how force regulates the talin-F0/Rap1b interaction. To explore the effect of force on the binding affinity and the dynamics mechanisms of talin-F0/Rap1b, molecular dynamics simulation was used to observe and compare the changes in functional and conformational information of the complex under different forces. Our results showed that when the complex was subjected to tensile forces, there were at least two dissociation pathways with significantly different mechanical strengths. The key event determining the mechanical strength difference between the two pathways was whether the β4 sheet of the F0 domain was pulled away from the original β1-β4 parallel structure. As the force increased, the talin-F0/Rap1b interaction first strengthened and then weakened, exhibiting the signature of a transition from catch bonds to slip bonds. The mechanical load of 20 pN increased the interaction index of two residue pairs, ASP 54-ARG 41 and GLN 18-THR 65, which resulted in a significant increase in the affinity of the complex. This study predicts the regulatory mechanism of the talin-F0/Rap1b interaction by forces in the intracellular environment and provides novel ideas for the treatment of related diseases and drug development.
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Affiliation(s)
- 哲 余
- 华南理工大学 生物科学与工程学院(广州 510006)School of Bioscience & Bioengineering, South China University of Technology, Guangzhou 510006, P. R. China
| | - 彦儒 姬
- 华南理工大学 生物科学与工程学院(广州 510006)School of Bioscience & Bioengineering, South China University of Technology, Guangzhou 510006, P. R. China
| | - 文华 黄
- 华南理工大学 生物科学与工程学院(广州 510006)School of Bioscience & Bioengineering, South China University of Technology, Guangzhou 510006, P. R. China
| | - 颖 方
- 华南理工大学 生物科学与工程学院(广州 510006)School of Bioscience & Bioengineering, South China University of Technology, Guangzhou 510006, P. R. China
| | - 建华 吴
- 华南理工大学 生物科学与工程学院(广州 510006)School of Bioscience & Bioengineering, South China University of Technology, Guangzhou 510006, P. R. China
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16
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Chen B, Meng X, Wu W, Zhang Y, Ma L, Chen K, Fang X. A novel CEST-contrast nanoagent for differentiating the malignant degree in breast cancer. RSC Adv 2023; 13:14131-14138. [PMID: 37180024 PMCID: PMC10167945 DOI: 10.1039/d3ra01006f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 05/03/2023] [Indexed: 05/15/2023] Open
Abstract
Different subtypes of breast cancer (BCC) have variable degrees of malignancy, which is closely related to their extracellular pH (pHe). Therefore, it is increasingly significant to monitor the extracellular pH sensitively to further determine the malignancy of different subtypes of BCC. Here, a l-arginine and Eu3+ assembled nanoparticle Eu3+@l-Arg was prepared to detect the pHe of two breast cancer models (TUBO is non-invasive and 4T1 is malignant) using a clinical chemical exchange saturation shift imaging technique. The experiments in vivo showed that Eu3+@l-Arg nanomaterials could respond sensitively to changes of pHe. In 4T1 models, the CEST signal enhanced about 5.42 times after Eu3+@l-Arg nanomaterials were used to detect the pHe. In contrast, few enhancements of the CEST signal were seen in the TUBO models. This significant difference had led to new ideas for identifying subtypes of BCC with different degrees of malignancy.
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Affiliation(s)
- Bixue Chen
- Department of Radiology, The Affiliated Wuxi People's Hospital of Nanjing Medical University Wuxi China
| | - Xianfu Meng
- Department of Medical Ultrasound, Shanghai Tenth People's Hospital, School of Medicine, Tongji University Shanghai China
- Department of Materials Science, State Key Laboratory of Molecular Engineering of Polymers, Fudan University Shanghai China
| | - Wanlu Wu
- Department of Radiology, The Affiliated Wuxi People's Hospital of Nanjing Medical University Wuxi China
| | - Yuwen Zhang
- Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University Shanghai China
| | - Lin Ma
- Department of Radiology, The Affiliated Wuxi People's Hospital of Nanjing Medical University Wuxi China
| | - Kaidong Chen
- Department of Radiology, The Affiliated Wuxi People's Hospital of Nanjing Medical University Wuxi China
| | - Xiangming Fang
- Department of Radiology, The Affiliated Wuxi People's Hospital of Nanjing Medical University Wuxi China
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17
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Liu JY, Zhou L, Shen Y. Inward rectifying K ir4.1 channels regulate oligodendrocyte precursor cell differentiation and CNS myelination in vivo. Neurosci Lett 2023; 807:137278. [PMID: 37116573 DOI: 10.1016/j.neulet.2023.137278] [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: 03/05/2023] [Revised: 04/21/2023] [Accepted: 04/24/2023] [Indexed: 04/30/2023]
Abstract
The functions of Kir4.1 in oligodendrocyte development have been in controversial. We recently reported that inhibiting Kir4.1 impeded oligodendrocyte precursor cell (OPC) differentiation and oligodendrocyte (OL) maturation, due to Kir4.1 altering intracellular pH of OPCs through Na+/H+ exchangers. However, our conclusion was limited by in vitro observation, thereby it becomes necessary to seek in vivo evidence to determine the roles of Kir4.1 on OPC development and CNS myelination. Here, we used Olig1-Cre to knockout Kir4.1 in OPCs from the early developmental stage. We found that the cell-specific deletion of Kir4.1 significantly impeded OPC differentiation and reduced the number of mature OLs in the cerebral cortex and the corpus callosum. Hence, our in vivo evidence supports that Kir4.1 can regulate OPC differentiation and is essential to CNS myelination.
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Affiliation(s)
- Jia-Yu Liu
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
| | - Liang Zhou
- Key Laboratory of Brain Science, Guizhou Institution of Higher Education, Zunyi Medical University, Zunyi, People's Republic of China
| | - Ying Shen
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, People's Republic of China.
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18
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Kanchanawong P, Calderwood DA. Organization, dynamics and mechanoregulation of integrin-mediated cell-ECM adhesions. Nat Rev Mol Cell Biol 2023; 24:142-161. [PMID: 36168065 PMCID: PMC9892292 DOI: 10.1038/s41580-022-00531-5] [Citation(s) in RCA: 211] [Impact Index Per Article: 105.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/10/2022] [Indexed: 02/04/2023]
Abstract
The ability of animal cells to sense, adhere to and remodel their local extracellular matrix (ECM) is central to control of cell shape, mechanical responsiveness, motility and signalling, and hence to development, tissue formation, wound healing and the immune response. Cell-ECM interactions occur at various specialized, multi-protein adhesion complexes that serve to physically link the ECM to the cytoskeleton and the intracellular signalling apparatus. This occurs predominantly via clustered transmembrane receptors of the integrin family. Here we review how the interplay of mechanical forces, biochemical signalling and molecular self-organization determines the composition, organization, mechanosensitivity and dynamics of these adhesions. Progress in the identification of core multi-protein modules within the adhesions and characterization of rearrangements of their components in response to force, together with advanced imaging approaches, has improved understanding of adhesion maturation and turnover and the relationships between adhesion structures and functions. Perturbations of adhesion contribute to a broad range of diseases and to age-related dysfunction, thus an improved understanding of their molecular nature may facilitate therapeutic intervention in these conditions.
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Affiliation(s)
- Pakorn Kanchanawong
- Mechanobiology Institute, National University of Singapore, Singapore, Singapore.
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore.
| | - David A Calderwood
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT, USA.
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA.
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19
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Simonyan TR, Protasova EA, Mamontova AV, Shakhov AM, Lukyanov KA, Maksimov EG, Bogdanov AM. A Single Fluorescent Protein-Based Indicator with a Time-Resolved Fluorescence Readout for Precise pH Measurements in the Alkaline Range. Int J Mol Sci 2022; 23:12907. [PMID: 36361706 PMCID: PMC9658282 DOI: 10.3390/ijms232112907] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 10/22/2022] [Accepted: 10/23/2022] [Indexed: 09/19/2023] Open
Abstract
The real-time monitoring of the intracellular pH in live cells with high precision represents an important methodological challenge. Although genetically encoded fluorescent indicators can be considered as a probe of choice for such measurements, they are hindered mostly by the inability to determine an absolute pH value and/or a narrow dynamic range of the signal, making them inefficient for recording the small pH changes that typically occur within cellular organelles. Here, we study the pH sensitivity of a green-fluorescence-protein (GFP)-based emitter (EGFP-Y145L/S205V) with the alkaline-shifted chromophore's pKa and demonstrate that, in the pH range of 7.5-9.0, its fluorescence lifetime changes by a factor of ~3.5 in a quasi-linear manner in mammalian cells. Considering the relatively strong lifetime response in a narrow pH range, we proposed the mitochondria, which are known to have a weakly alkaline milieu, as a target for live-cell pH measurements. Using fluorescence lifetime imaging microscopy (FLIM) to visualize the HEK293T cells expressing mitochondrially targeted EGFP-Y145L/S205V, we succeeded in determining the absolute pH value of the mitochondria and recorded the ETC-uncoupler-stimulated pH shift with a precision of 0.1 unit. We thus show that a single GFP with alkaline-shifted pKa can act as a high-precision indicator that can be used in a specific pH range.
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Affiliation(s)
- Tatiana R. Simonyan
- Center of Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, 121205 Moscow, Russia
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia
| | - Elena A. Protasova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia
- Faculty of Biology, M.V. Lomonosov Moscow State University, 119992 Moscow, Russia
| | - Anastasia V. Mamontova
- Center of Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, 121205 Moscow, Russia
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia
| | - Aleksander M. Shakhov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia
- Semenov Federal Research Center for Chemical Physics, 119991 Moscow, Russia
| | | | - Eugene G. Maksimov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia
- Faculty of Biology, M.V. Lomonosov Moscow State University, 119992 Moscow, Russia
| | - Alexey M. Bogdanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia
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20
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Wang N, Zhou L, Shao CY, Wang XT, Zhang N, Ma J, Hu HL, Wang Y, Qiu M, Shen Y. Potassium channel K ir 4.1 regulates oligodendrocyte differentiation via intracellular pH regulation. Glia 2022; 70:2093-2107. [PMID: 35775976 DOI: 10.1002/glia.24240] [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] [Received: 01/11/2022] [Revised: 06/06/2022] [Accepted: 06/24/2022] [Indexed: 11/10/2022]
Abstract
In humans, loss-of-function mutations of Kcnj10 in SeSAME/EAST syndrome, which encodes the inwardly rectifying K+ channel 4.1 (Kir 4.1), causes progressive neurological decline. Despite its rich expression in oligodendrocyte (OL) lineage cells and an emerging link with demyelinating disease, the function of Kir 4.1 in OLs is unclear. Here we show a novel role of Kir 4.1 in OL development. Kir 4.1 expression is markedly greater in OLs than in OL precursor cells (OPCs), and the down-regulation of Kir 4.1 impairs OL maturation by affecting OPC differentiation. Interestingly, Kir 4.1 regulates the intracellular pH of OPCs and OLs via the Na+ /H+ exchanger, which underlies impeded OPC differentiation by Kir 4.1 inhibition. Furthermore, Kir 4.1 regulates GSK3β and SOX10, two molecules critical to OPC development. Collectively, our work opens a new avenue to understanding the functions of Kir 4.1 and intracellular pH in OLs.
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Affiliation(s)
- Na Wang
- Department of Physiology and Department of Neurology of the First Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Liang Zhou
- Department of Physiology and Department of Neurology of the First Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Brain Science, Guizhou Institution of Higher Education, Zunyi Medical University, Zunyi, China
| | - Chong-Yu Shao
- Department of Physiology and Department of Neurology of the First Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Xin-Tai Wang
- Department of Physiology and Department of Neurology of the First Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Nan Zhang
- Key Laboratory of Cranial Cerebral Diseases, Department of Neurobiology of Basic Medical College, Ningxia Medical University, Yinchuan, China
| | - Jiao Ma
- Key Laboratory of Cranial Cerebral Diseases, Department of Neurobiology of Basic Medical College, Ningxia Medical University, Yinchuan, China
| | - Hai-Lan Hu
- Interdisciplinary Institute of Neuroscience and Technology, Qiushi Academy for Advanced Studies, Zhejiang University, Hangzhou, China
| | - Yin Wang
- Key Laboratory of Cranial Cerebral Diseases, Department of Neurobiology of Basic Medical College, Ningxia Medical University, Yinchuan, China
| | - Mengsheng Qiu
- Institute of Life Sciences, Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Ying Shen
- Department of Physiology and Department of Neurology of the First Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
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21
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Rosen ME, Dallon JC. A mathematical analysis of focal adhesion lifetimes and their effect on cell motility. Biophys J 2022; 121:1070-1080. [PMID: 35143774 PMCID: PMC8943753 DOI: 10.1016/j.bpj.2022.02.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 12/07/2021] [Accepted: 02/03/2022] [Indexed: 11/02/2022] Open
Abstract
By analyzing the distributions of focal adhesion (FA) lifetimes from different cell types, we found that a gamma distribution best matched the experimental distributions. In all but one case, it was a unimodal, non-symmetric gamma distribution. We used a mathematical model of cell motion to help understand the mechanics and data behind the FA lifetime distributions. The model uses a detach-rate function to determine how long an FA will persist before it detaches. The detach-rate function that produced distributions with a best-fit gamma curve that closely matched that of the data was both force and time dependent. Using the data gathered from the matching simulations, we calculated both the cell speed and mean FA lifetime and compared them. Where available, we also compared this relationship to that of the experimental data and found that the simulation reasonably matches it in most cases. In both the simulations and experimental data, the cell speed and mean FA lifetime are related, with longer mean lifetimes being indicative of slower speeds. We suspect that one of the main predictors of cell speed for migrating cells is the distribution of the FA lifetimes.
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Affiliation(s)
- Mary Ellen Rosen
- Department of Mathematics, Brigham Young University, Provo, Utah
| | - J C Dallon
- Department of Mathematics, Brigham Young University, Provo, Utah.
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22
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The C-terminal actin-binding domain of talin forms an asymmetric catch bond with F-actin. Proc Natl Acad Sci U S A 2022; 119:e2109329119. [PMID: 35245171 PMCID: PMC8915792 DOI: 10.1073/pnas.2109329119] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Talin is a mechanosensitive adaptor protein that links integrins to the actin cytoskeleton at cell–extracellular matrix adhesions. Although the C-terminal actin-binding domain ABS3 of talin is required for function, it binds weakly to actin in solution. We show that ABS3 binds actin strongly only when subjected to mechanical forces comparable to those generated by the cytoskeleton. Moreover, the interaction between ABS3 and actin depends strongly on the direction of force in a manner predicted to organize actin to facilitate adhesion growth and efficient cytoskeletal force generation. These characteristics can explain how force sensing by talin helps to nucleate adhesions precisely when and where they are required to transmit force between the cytoskeleton and the extracellular matrix. Focal adhesions (FAs) are large, integrin-based protein complexes that link cells to the extracellular matrix (ECM). FAs form only when and where they are necessary to transmit force between the cellular cytoskeleton and the ECM, but how this occurs remains poorly understood. Talin is a 270-kDa adaptor protein that links integrins to filamentous (F)-actin and recruits additional components during FA assembly in a force-dependent manner. Cell biological and developmental data demonstrate that the third and C-terminal F-actin–binding site (ABS3) of talin is required for normal FA formation. However, purified ABS3 binds F-actin only weakly in solution. We used a single molecule optical trap assay to examine how and whether ABS3 binds F-actin under physiologically relevant mechanical loads. We find that ABS3 forms a catch bond with F-actin when force is applied toward the pointed end of the actin filament, with binding lifetimes >100-fold longer than when force is applied toward the barbed end. Long-lived bonds to F-actin under load require the ABS3 C-terminal dimerization domain, whose cleavage has been reported to regulate FA turnover. Our results support a mechanism in which talin ABS3 preferentially binds to and orients actin filaments with barbed ends facing the cell periphery, thus nucleating long-range order in the actin cytoskeleton. We suggest that talin ABS3 may function as a molecular AND gate that allows FA growth only when sufficient integrin density, F-actin polarization, and mechanical tension are simultaneously present.
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23
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Case LB, De Pasquale M, Henry L, Rosen MK. Synergistic phase separation of two pathways promotes integrin clustering and nascent adhesion formation. eLife 2022; 11:e72588. [PMID: 35049497 PMCID: PMC8791637 DOI: 10.7554/elife.72588] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 01/10/2022] [Indexed: 12/14/2022] Open
Abstract
Integrin adhesion complexes (IACs) are integrin-based plasma-membrane-associated compartments where cells sense environmental cues. The physical mechanisms and molecular interactions that mediate initial IAC formation are unclear. We found that both p130Cas ('Cas') and Focal adhesion kinase ('FAK') undergo liquid-liquid phase separation in vitro under physiologic conditions. Cas- and FAK- driven phase separation is sufficient to reconstitute kindlin-dependent integrin clustering in vitro with recombinant mammalian proteins. In vitro condensates and IACs in mouse embryonic fibroblasts (MEFs) exhibit similar sensitivities to environmental perturbations including changes in temperature and pH. Furthermore, mutations that inhibit or enhance phase separation in vitro reduce or increase the number of IACs in MEFs, respectively. Finally, we find that the Cas and FAK pathways act synergistically to promote phase separation, integrin clustering, IAC formation and partitioning of key components in vitro and in cells. We propose that Cas- and FAK-driven phase separation provides an intracellular trigger for integrin clustering and nascent IAC formation.
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Affiliation(s)
- Lindsay B Case
- Department of Biophysics, Howard Hughes Medical Institute, The University of Texas Southwestern Medical CenterDallasUnited States
- Department of Biology, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Milagros De Pasquale
- Department of Biology, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Lisa Henry
- Department of Biophysics, Howard Hughes Medical Institute, The University of Texas Southwestern Medical CenterDallasUnited States
| | - Michael K Rosen
- Department of Biophysics, Howard Hughes Medical Institute, The University of Texas Southwestern Medical CenterDallasUnited States
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24
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Donahue CET, Siroky MD, White KA. An Optogenetic Tool to Raise Intracellular pH in Single Cells and Drive Localized Membrane Dynamics. J Am Chem Soc 2021; 143:18877-18887. [PMID: 34726911 PMCID: PMC8603357 DOI: 10.1021/jacs.1c02156] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
![]()
Intracellular pH
(pHi) dynamics are critical for regulating normal
cell physiology. For example, transient increases in pHi (7.2–7.6)
regulate cell behaviors like cell polarization, actin cytoskeleton
remodeling, and cell migration. Most studies on pH-dependent cell
behaviors have been performed at the population level and use nonspecific
methods to manipulate pHi. The lack of tools to specifically manipulate
pHi at the single-cell level has hindered investigation of the role
of pHi dynamics in driving single cell behaviors. In this work, we
show that Archaerhodopsin (ArchT), a light-driven outward proton pump,
can be used to elicit robust and physiological pHi increases over
the minutes time scale. We show that activation of ArchT is repeatable,
enabling the maintenance of high pHi in single cells for up to 45
minutes. We apply this spatiotemporal pHi manipulation tool to determine
whether increased pHi is a sufficient driver of membrane ruffling
in single cells. Using the ArchT tool, we show that increased pHi
in single cells can drive localized membrane ruffling responses within
seconds and increased membrane dynamics (both protrusion and retraction
events) compared to unstimulated ArchT cells as well as control cells.
Overall, this tool allows us to directly investigate the relationship
between increased pHi and single cell behaviors such as membrane ruffling.
This tool will be transformative in facilitating experiments that
are required to determine roles for increased pHi in driving single
cell behaviors.
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Affiliation(s)
- Caitlin E T Donahue
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States.,Mike and Josie Harper Cancer Research Institute, University of Notre Dame, South Bend, Indiana 46617, United States
| | - Michael D Siroky
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States.,Mike and Josie Harper Cancer Research Institute, University of Notre Dame, South Bend, Indiana 46617, United States
| | - Katharine A White
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States.,Mike and Josie Harper Cancer Research Institute, University of Notre Dame, South Bend, Indiana 46617, United States
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25
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Kim J. A possible molecular mechanism for mechanotransduction at cellular focal adhesion complexes. BIOPHYSICAL REPORTS 2021; 1:100006. [PMID: 36425310 PMCID: PMC9680735 DOI: 10.1016/j.bpr.2021.100006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 07/13/2021] [Indexed: 06/16/2023]
Abstract
Mechanotransduction at focal adhesion complexes is key for various cellular events. Theoretical analyses were performed to predict a potential role of lipid membranes in modulating mechanotransduction at focal adhesions. Calculations suggested that the size of nanostructural constraints and mechanical pulling applied on lipid membranes affect the generation of cellular traction forces and signaling transduction at focal adhesions. This work provides predictions on how lipid membranes contribute to mechanotransduction at cellular focal adhesions.
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Affiliation(s)
- Jichul Kim
- Independent Researcher, Changwon, Republic of Korea
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26
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Ion Channels, Transporters, and Sensors Interact with the Acidic Tumor Microenvironment to Modify Cancer Progression. Rev Physiol Biochem Pharmacol 2021; 182:39-84. [PMID: 34291319 DOI: 10.1007/112_2021_63] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Solid tumors, including breast carcinomas, are heterogeneous but typically characterized by elevated cellular turnover and metabolism, diffusion limitations based on the complex tumor architecture, and abnormal intra- and extracellular ion compositions particularly as regards acid-base equivalents. Carcinogenesis-related alterations in expression and function of ion channels and transporters, cellular energy levels, and organellar H+ sequestration further modify the acid-base composition within tumors and influence cancer cell functions, including cell proliferation, migration, and survival. Cancer cells defend their cytosolic pH and HCO3- concentrations better than normal cells when challenged with the marked deviations in extracellular H+, HCO3-, and lactate concentrations typical of the tumor microenvironment. Ionic gradients determine the driving forces for ion transporters and channels and influence the membrane potential. Cancer and stromal cells also sense abnormal ion concentrations via intra- and extracellular receptors that modify cancer progression and prognosis. With emphasis on breast cancer, the current review first addresses the altered ion composition and the changes in expression and functional activity of ion channels and transporters in solid cancer tissue. It then discusses how ion channels, transporters, and cellular sensors under influence of the acidic tumor microenvironment shape cancer development and progression and affect the potential of cancer therapies.
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27
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Sarkar A, Roitberg AE. pH-Dependent Conformational Changes Lead to a Highly Shifted p Ka for a Buried Glutamic Acid Mutant of SNase. J Phys Chem B 2020; 124:11072-11080. [PMID: 33259714 DOI: 10.1021/acs.jpcb.0c07136] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ionizable residues are rarely present in the hydrophobic interior of proteins, but when they are, they play important roles in biological processes such as energy transduction and enzyme catalysis. Internal ionizable residues have anomalous experimental pKa values with respect to their pKa in bulk water. This work investigates the atomistic cause of the highly shifted pKa of the internal Glu23 in the artificially mutated variant V23E of Staphylococcal Nuclease (SNase) using pH replica exchange molecular dynamics (pH-REMD) simulations. The pKa of Glu23 obtained from our calculations is 6.55, which is elevated with respect to the glutamate pKa of 4.40 in bulk water. The calculated value is close to the experimental pKa of 7.10. Our simulations show that the highly shifted pKa of Glu23 is the product of a pH-dependent conformational change, which has been observed experimentally and also seen in our simulations. We carry out an analysis of this pH-dependent conformational change in response to the protonation state change of Glu23. Using a four-state thermodynamic model, we estimate the two conformation-specific pKa values of Glu23 and describe the coupling between the conformational and ionization equilibria.
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Affiliation(s)
- Ankita Sarkar
- Department of Physics, University of Florida, Gainesville, Florida 32611, United States
| | - Adrian E Roitberg
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
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28
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Kumawat A, Chakrabarty S. Protonation-Induced Dynamic Allostery in PDZ Domain: Evidence of Perturbation-Independent Universal Response Network. J Phys Chem Lett 2020; 11:9026-9031. [PMID: 33043672 DOI: 10.1021/acs.jpclett.0c02885] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Dynamic allostery is a relatively new paradigm where certain external perturbations may lead to modulation of conformational dynamics at a distant part of a protein without significant changes in the overall structure. While most well-characterized examples of dynamic allostery involve binding with other entities like small molecules, peptides, or nucleic acids, in this work we demonstrate that chemical modifications like protonation may lead to significant dynamical allosteric response in a PDZ domain protein. Tuning the protonation states of two histidine residues (H317 and H372), we identify the allosteric pathways responsible for the dynamic response. Interestingly, the same set of residues that constitute the allosteric response network upon ligand binding seem to be responsible for protonation-induced dynamic allostery. Thus, we propose the existence of an inherent universal response network in signaling proteins, where the same set of residues can respond to varying types of external perturbations in terms of rearrangement of hydrogen-bonded network and redistribution of electrostatic interaction energies.
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Affiliation(s)
- Amit Kumawat
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Pune 411008, India
| | - Suman Chakrabarty
- Department of Chemical, Biological & Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Kolkata 700106, India
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29
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Cancer and pH Dynamics: Transcriptional Regulation, Proteostasis, and the Need for New Molecular Tools. Cancers (Basel) 2020; 12:cancers12102760. [PMID: 32992762 PMCID: PMC7601256 DOI: 10.3390/cancers12102760] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 09/18/2020] [Accepted: 09/21/2020] [Indexed: 12/11/2022] Open
Abstract
An emerging hallmark of cancer cells is dysregulated pH dynamics. Recent work has suggested that dysregulated intracellular pH (pHi) dynamics enable diverse cancer cellular behaviors at the population level, including cell proliferation, cell migration and metastasis, evasion of apoptosis, and metabolic adaptation. However, the molecular mechanisms driving pH-dependent cancer-associated cell behaviors are largely unknown. In this review article, we explore recent literature suggesting pHi dynamics may play a causative role in regulating or reinforcing tumorigenic transcriptional and proteostatic changes at the molecular level, and discuss outcomes on tumorigenesis and tumor heterogeneity. Most of the data we discuss are population-level analyses; lack of single-cell data is driven by a lack of tools to experimentally change pHi with spatiotemporal control. Data is also sparse on how pHi dynamics play out in complex in vivo microenvironments. To address this need, at the end of this review, we cover recent advances for live-cell pHi measurement at single-cell resolution. We also discuss the essential role for tool development in revealing mechanisms by which pHi dynamics drive tumor initiation, progression, and metastasis.
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30
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Daunys S, Petrikaitė V. The roles of carbonic anhydrases IX and XII in cancer cell adhesion, migration, invasion and metastasis. Biol Cell 2020; 112:383-397. [PMID: 32894882 DOI: 10.1111/boc.201900099] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 09/02/2012] [Indexed: 12/17/2022]
Abstract
The main function of carbonic anhydrases (CAs) in cancer cells is the pH regulation through a conversion of H2 O and CO2 to H+ and HCO3 - . However, the data of in vitro and in vivo studies have demonstrated that transmembrane isoforms of CA IX and CA XII are involved in various steps of cancer cell migration, invasion and metastasis. According to literature, inhibition of these CAs can affect the expression of multiple proteins. Some scientific groups have reported the possible interactions between CA IX and E-cadherin-catenin system, CA IX and integrins, CA IX, CA XII and ion transporters, which all are highly involved in cell-to-cell adhesion, the formation of membrane protrusions and focal adhesions. Nevertheless, CA IX and CA XII have a high impact on tumour growth and metastases formation. The data discussed in this review are quite recent. It highly support the role of CA IX and CA XII in various cancer metastasis processes through their interactions to other invasion proteins. Nevertheless, all findings show the great potential of these CAs in the context of research and application in clinical use.
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Affiliation(s)
- Simonas Daunys
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Vilnius, LT-10257, Lithuania
| | - Vilma Petrikaitė
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Vilnius, LT-10257, Lithuania.,Laboratory of Drug Targets Histopathology, Institute of Cardiology, Lithuanian University of Health Sciences, Kaunas, LT-50162, Lithuania
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31
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Pethő Z, Najder K, Carvalho T, McMorrow R, Todesca LM, Rugi M, Bulk E, Chan A, Löwik CWGM, Reshkin SJ, Schwab A. pH-Channeling in Cancer: How pH-Dependence of Cation Channels Shapes Cancer Pathophysiology. Cancers (Basel) 2020; 12:E2484. [PMID: 32887220 PMCID: PMC7565548 DOI: 10.3390/cancers12092484] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 08/25/2020] [Accepted: 08/26/2020] [Indexed: 12/20/2022] Open
Abstract
Tissue acidosis plays a pivotal role in tumor progression: in particular, interstitial acidosis promotes tumor cell invasion, and is a major contributor to the dysregulation of tumor immunity and tumor stromal cells. The cell membrane and integral membrane proteins commonly act as important sensors and transducers of altered pH. Cell adhesion molecules and cation channels are prominent membrane proteins, the majority of which is regulated by protons. The pathophysiological consequences of proton-sensitive ion channel function in cancer, however, are scarcely considered in the literature. Thus, the main focus of this review is to highlight possible events in tumor progression and tumor immunity where the pH sensitivity of cation channels could be of great importance.
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Affiliation(s)
- Zoltán Pethő
- Institute of Physiology II, University Münster, 48147 Münster, Germany; (K.N.); (L.M.T.); (M.R.); (E.B.); (A.S.)
| | - Karolina Najder
- Institute of Physiology II, University Münster, 48147 Münster, Germany; (K.N.); (L.M.T.); (M.R.); (E.B.); (A.S.)
| | - Tiago Carvalho
- Department of Biosciences, Biotechnologies, and Biopharmaceutics, University of Bari, 90126 Bari, Italy; (T.C.); (S.J.R.)
| | - Roisin McMorrow
- Department of Radiology and Nuclear Medicine, Erasmus Medical Center, 3035 GD Rotterdam, The Netherlands; (R.M.); (C.W.G.M.L.)
| | - Luca Matteo Todesca
- Institute of Physiology II, University Münster, 48147 Münster, Germany; (K.N.); (L.M.T.); (M.R.); (E.B.); (A.S.)
| | - Micol Rugi
- Institute of Physiology II, University Münster, 48147 Münster, Germany; (K.N.); (L.M.T.); (M.R.); (E.B.); (A.S.)
| | - Etmar Bulk
- Institute of Physiology II, University Münster, 48147 Münster, Germany; (K.N.); (L.M.T.); (M.R.); (E.B.); (A.S.)
| | - Alan Chan
- Percuros B.V., 2333 CL Leiden, The Netherlands;
| | - Clemens W. G. M. Löwik
- Department of Radiology and Nuclear Medicine, Erasmus Medical Center, 3035 GD Rotterdam, The Netherlands; (R.M.); (C.W.G.M.L.)
- Department of Oncology CHUV, UNIL and Ludwig Cancer Center, 1011 Lausanne, Switzerland
| | - Stephan J. Reshkin
- Department of Biosciences, Biotechnologies, and Biopharmaceutics, University of Bari, 90126 Bari, Italy; (T.C.); (S.J.R.)
| | - Albrecht Schwab
- Institute of Physiology II, University Münster, 48147 Münster, Germany; (K.N.); (L.M.T.); (M.R.); (E.B.); (A.S.)
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32
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Liu Y, White KA, Barber DL. Intracellular pH Regulates Cancer and Stem Cell Behaviors: A Protein Dynamics Perspective. Front Oncol 2020; 10:1401. [PMID: 32983969 PMCID: PMC7479815 DOI: 10.3389/fonc.2020.01401] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 07/02/2020] [Indexed: 12/12/2022] Open
Abstract
The International Society of Cancer Metabolism (ISCaM) meeting on Cancer Metabolic Rewiring, held in Braga Portugal in October 2019, provided an outstanding forum for investigators to present current findings and views, and discuss ideas and future directions on fundamental biology as well as clinical translations. The first session on Cancer pH Dynamics was preceded by the opening keynote presentation from our group entitled Intracellular pH Regulation of Protein Dynamics: From Cancer to Stem Cell Behaviors. In this review we introduce a brief background on intracellular pH (pHi) dynamics, including how it is regulated as well as functional consequences, summarize key findings included in our presentation, and conclude with perspectives on how understanding the role of pHi dynamics in stem cells can be relevant for understanding how pHi dynamics enables cancer progression.
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Affiliation(s)
- Yi Liu
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA, United States
| | - Katharine A White
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA, United States
| | - Diane L Barber
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA, United States
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33
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Song Y, Li C, Fu Y, Xie Q, Guo J, Li G, Wu H. Inward Tension of Talin and Integrin-related Osmotic Pressure are involved Synergetically in the Invasion and Metastasis of Non-small Cell Lung Cancer. J Cancer 2020; 11:5032-5041. [PMID: 32742451 PMCID: PMC7378908 DOI: 10.7150/jca.45494] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 05/19/2020] [Indexed: 12/24/2022] Open
Abstract
The integrin receptor protein talin plays vital roles in intracellular chemical and mechanical activities, and it is implicated in the high invasion and poor prognosis of non-small cell lung cancer (NSCLC). To better understand the mechanism underlying the function of talin in NSCLC invasion and metastasis, a few newly designed tension probe based on Förster resonance energy transfer was used for real-time observation of tension changes in A549 cells. High NSCLC cell aggressiveness was found to be accompanied with inward talin and outward glial fibrillary acidic protein (GFAP) tensions, which are closely associated with microfilament (MF) force and intracellular osmotic potential. The increased osmotic pressure resulted from the production of intracellular protein nanoparticles and the related ion influx. Furthermore, integrin activation was found to adjust the talin and GFAP tensions. Disruption of the interaction between talin and MFs blocked the mechanical source of talin, reducing both talin tension and osmotic pressure and thus inhibiting NSCLC cell invasion and migration. Consequently, our study demonstrates that talin is involved in NSCLC invasion and migration via its inward tension and that the integrin pathway is correlated closely with protein-nanoparticle-induced outward osmotic pressure.
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Affiliation(s)
- Ying Song
- Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, PR China
| | - Chen Li
- School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, PR China
| | - Yahan Fu
- School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, PR China
| | - Qiu Xie
- School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, PR China
| | - Jun Guo
- School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, PR China
| | - Guangming Li
- Department of Anesthesiology, Huaian First People's Hospital, Nanjing Medical University, Huaian 223001, PR China
| | - Huiwen Wu
- Laboratory Center for Basic Medical Sciences, Nanjing Medical University, Nanjing 211166, PR China
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34
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Iorio J, Duranti C, Lottini T, Lastraioli E, Bagni G, Becchetti A, Arcangeli A. K V11.1 Potassium Channel and the Na +/H + Antiporter NHE1 Modulate Adhesion-Dependent Intracellular pH in Colorectal Cancer Cells. Front Pharmacol 2020; 11:848. [PMID: 32587517 PMCID: PMC7297984 DOI: 10.3389/fphar.2020.00848] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 05/22/2020] [Indexed: 12/16/2022] Open
Abstract
Increasing evidence indicates that ion channels and transporters cooperate in regulating different aspects of tumor pathophysiology. In cancer cells, H+/HCO3- transporters usually invert the transmembrane pH gradient typically observed in non-neoplastic cells, which is thought to contribute to cancer malignancy. To what extent the pH-regulating transporters are functionally linked to K+ channels, which are central regulators of cell membrane potential (Vm), is unclear. We thus investigated in colorectal cancer cells the implication of the pH-regulating transporters and KV11.1 (also known as hERG1) in the pH modifications stimulated by integrin-dependent cell adhesion. Colorectal cancer cell lines (HCT 116 and HT 29) were seeded onto β1 integrin-dependent substrates, collagen I and fibronectin. This led to a transient cytoplasmic alkalinization, which peaked at 90 min of incubation, lasted approximately 180 min, and was inhibited by antibodies blocking the β1 integrin. The effect was sensitive to amiloride (10 µM) and cariporide (5 µM), suggesting that it was mainly caused by the activity of the Na+/H+ antiporter NHE1. Blocking KV11.1 with E4031 shows that channel activity contributed to modulate the β1 integrin-dependent pHi increase. Interestingly, both NHE1 and KV11.1 modulated the colorectal cancer cell motility triggered by β1 integrin-dependent adhesion. Finally, the β1 integrin subunit, KV11.1 and NHE1 co-immunoprecipitated in colorectal cancer cells seeded onto Collagen I, suggesting the formation of a macromolecular complex following integrin-mediated adhesion. We conclude that the interaction between KV11.1, NHE1, and β1 integrin contributes to regulate colorectal cancer intracellular pH in relation to the tumor microenvironment, suggesting novel pharmacological targets to counteract pro-invasive and, hence, pro-metastatic behavior in colorectal cancer.
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Affiliation(s)
- Jessica Iorio
- Section of Internal Medicine, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Claudia Duranti
- Section of Internal Medicine, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Tiziano Lottini
- Section of Internal Medicine, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Elena Lastraioli
- Section of Internal Medicine, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Giacomo Bagni
- Section of Internal Medicine, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Andrea Becchetti
- Department of Biotechnology and Biosciences, University of Milano Bicocca, Milano, Italy
| | - Annarosa Arcangeli
- Section of Internal Medicine, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
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35
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Ward C, Meehan J, Gray ME, Murray AF, Argyle DJ, Kunkler IH, Langdon SP. The impact of tumour pH on cancer progression: strategies for clinical intervention. EXPLORATION OF TARGETED ANTI-TUMOR THERAPY 2020; 1:71-100. [PMID: 36046070 PMCID: PMC9400736 DOI: 10.37349/etat.2020.00005] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 02/05/2020] [Indexed: 02/06/2023] Open
Abstract
Dysregulation of cellular pH is frequent in solid tumours and provides potential opportunities for therapeutic intervention. The acidic microenvironment within a tumour can promote migration, invasion and metastasis of cancer cells through a variety of mechanisms. Pathways associated with the control of intracellular pH that are under consideration for intervention include carbonic anhydrase IX, the monocarboxylate transporters (MCT, MCT1 and MCT4), the vacuolar-type H+-ATPase proton pump, and the sodium-hydrogen exchanger 1. This review will describe progress in the development of inhibitors to these targets.
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Affiliation(s)
- Carol Ward
- Cancer Research UK Edinburgh Centre and Edinburgh Pathology, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road South, EH4 2XU Edinburgh, UK
| | - James Meehan
- Cancer Research UK Edinburgh Centre and Edinburgh Pathology, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road South, EH4 2XU Edinburgh, UK
| | - Mark E Gray
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush, EH25 9RG Midlothian, UK
| | - Alan F Murray
- School of Engineering, Institute for Integrated Micro and Nano Systems, EH9 3JL Edinburgh, UK
| | - David J Argyle
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush, EH25 9RG Midlothian, UK
| | - Ian H Kunkler
- Cancer Research UK Edinburgh Centre and Edinburgh Pathology, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road South, EH4 2XU Edinburgh, UK
| | - Simon P Langdon
- Cancer Research UK Edinburgh Centre and Edinburgh Pathology, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road South, EH4 2XU Edinburgh, UK
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36
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Abstract
An unresolved question critical for understanding cancer is how recurring somatic mutations are retained and how selective pressures drive retention. Increased intracellular pH (pHi) is common to most cancers and is an early event in cancer development. Recent work shows that recurrent somatic mutations can confer an adaptive gain in pH sensing to mutant proteins, enhancing tumorigenic phenotypes specifically at the increased pHi of cancer. Newly identified amino acid mutation signatures in cancer suggest charge-changing mutations define and shape the mutational landscape of cancer. Taken together, these results support a new perspective on the functional significance of somatic mutations in cancer. In this review, we explore existing data and new directions for better understanding how changes in dynamic pH sensing by somatic mutation might be conferring a fitness advantage to the high pH of cancer.
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37
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Abstract
Acidic metabolic waste products accumulate in the tumor microenvironment because of high metabolic activity and insufficient perfusion. In tumors, the acidity of the interstitial space and the relatively well-maintained intracellular pH influence cancer and stromal cell function, their mutual interplay, and their interactions with the extracellular matrix. Tumor pH is spatially and temporally heterogeneous, and the fitness advantage of cancer cells adapted to extracellular acidity is likely particularly evident when they encounter less acidic tumor regions, for instance, during invasion. Through complex effects on genetic stability, epigenetics, cellular metabolism, proliferation, and survival, the compartmentalized pH microenvironment favors cancer development. Cellular selection exacerbates the malignant phenotype, which is further enhanced by acid-induced cell motility, extracellular matrix degradation, attenuated immune responses, and modified cellular and intercellular signaling. In this review, we discuss how the acidity of the tumor microenvironment influences each stage in cancer development, from dysplasia to full-blown metastatic disease.
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Affiliation(s)
- Ebbe Boedtkjer
- Department of Biomedicine, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Stine F. Pedersen
- Department of Biology, University of Copenhagen, DK-2100 Copenhagen, Denmark
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38
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Khan RB, Goult BT. Adhesions Assemble!-Autoinhibition as a Major Regulatory Mechanism of Integrin-Mediated Adhesion. Front Mol Biosci 2019; 6:144. [PMID: 31921890 PMCID: PMC6927945 DOI: 10.3389/fmolb.2019.00144] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 11/26/2019] [Indexed: 01/14/2023] Open
Abstract
The advent of cell-cell and cell-extracellular adhesion enabled cells to interact in a coherent manner, forming larger structures and giving rise to the development of tissues, organs and complex multicellular life forms. The development of such organisms required tight regulation of dynamic adhesive structures by signaling pathways that coordinate cell attachment. Integrin-mediated adhesion to the extracellular matrix provides cells with support, survival signals and context-dependent cues that enable cells to run different cellular programs. One mysterious aspect of the process is how hundreds of proteins assemble seemingly spontaneously onto the activated integrin. An emerging concept is that adhesion assembly is regulated by autoinhibition of key proteins, a highly dynamic event that is modulated by a variety of signaling events. By enabling precise control of the activation state of proteins, autoinhibition enables localization of inactive proteins and the formation of pre-complexes. In response to the correct signals, these proteins become active and interact with other proteins, ultimately leading to development of cell-matrix junctions. Autoinhibition of key components of such adhesion complexes—including core components integrin, talin, vinculin, and FAK and important peripheral regulators such as RIAM, Src, and DLC1—leads to a view that the majority of proteins involved in complex assembly might be regulated by intramolecular interactions. Autoinhibition is relieved via multiple different signals including post-translation modification and proteolysis. More recently, mechanical forces have been shown to stabilize and increase the lifetimes of active conformations, identifying autoinhibition as a means of encoding mechanosensitivity. The complexity and scope for nuanced adhesion dynamics facilitated via autoinhibition provides numerous points of regulation. In this review, we discuss what is known about this mode of regulation and how it leads to rapid and tightly controlled assembly and disassembly of cell-matrix adhesion.
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Affiliation(s)
- Rejina B Khan
- School of Biosciences, University of Kent, Canterbury, United Kingdom
| | - Benjamin T Goult
- School of Biosciences, University of Kent, Canterbury, United Kingdom
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39
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Rabiee Motmaen S, Tavakol S, Joghataei MT, Barati M. Acidic pH derived from cancer cells as a double-edged knife modulates wound healing through DNA repair genes and autophagy. Int Wound J 2019; 17:137-148. [PMID: 31714008 DOI: 10.1111/iwj.13248] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 09/18/2019] [Accepted: 09/22/2019] [Indexed: 12/16/2022] Open
Abstract
Wound healing is a sequester program that involves diverse cell signalling cascades. Notwithstanding, complete signal transduction pathways underpinning acidic milieu derived from cancer cells is not clear, yet. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, fluorescein diacetate/propidium iodide staining, and cell cycle flow cytometry revealed that acidic media decreased cell viability and cell number along with enhanced dead cells and S-phase arrest in normal fibroblasts. Notably, the trends of intracellular reactive oxygen species production and lactate dehydrogenase release significantly increased with time. It seems the downregulation of Klf4 is in part due to acidosis-induced DNA damage. It promoted cells towards S-phase arrest and diminished cell proliferation. Klf4 downregulation had a direct correlation with the P53 level while acidic microenvironment promotes cells towards cell death mechanisms including apoptosis and autophagy. Noteworthily, the unchanged levels of Rb and Mlh1 indicated in those genes had no dominant role in the repairing of DNA damage in fibroblasts treated with the acidic microenvironment. Therefore, cells owing to not entering to mitosis and accumulation of DNA damage were undergone cell death to preserve cell homeostasis. Since acidic media decreased the level of tumour suppressor and DNA repair genes and altered the normal survival pathways in fibroblasts, caution should be exercised to not lead to cancer rather than wound healing.
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Affiliation(s)
| | - Shima Tavakol
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad T Joghataei
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Mahmoud Barati
- Department of Medical Biotechnology, Iran University of Medical Sciences, Tehran, Iran
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40
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Pedersen SF, Counillon L. The SLC9A-C Mammalian Na +/H + Exchanger Family: Molecules, Mechanisms, and Physiology. Physiol Rev 2019; 99:2015-2113. [PMID: 31507243 DOI: 10.1152/physrev.00028.2018] [Citation(s) in RCA: 123] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Na+/H+ exchangers play pivotal roles in the control of cell and tissue pH by mediating the electroneutral exchange of Na+ and H+ across cellular membranes. They belong to an ancient family of highly evolutionarily conserved proteins, and they play essential physiological roles in all phyla. In this review, we focus on the mammalian Na+/H+ exchangers (NHEs), the solute carrier (SLC) 9 family. This family of electroneutral transporters constitutes three branches: SLC9A, -B, and -C. Within these, each isoform exhibits distinct tissue expression profiles, regulation, and physiological roles. Some of these transporters are highly studied, with hundreds of original articles, and some are still only rudimentarily understood. In this review, we present and discuss the pioneering original work as well as the current state-of-the-art research on mammalian NHEs. We aim to provide the reader with a comprehensive view of core knowledge and recent insights into each family member, from gene organization over protein structure and regulation to physiological and pathophysiological roles. Particular attention is given to the integrated physiology of NHEs in the main organ systems. We provide several novel analyses and useful overviews, and we pinpoint main remaining enigmas, which we hope will inspire novel research on these highly versatile proteins.
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Affiliation(s)
- S F Pedersen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark; and Université Côte d'Azur, CNRS, Laboratoire de Physiomédecine Moléculaire, LP2M, France, and Laboratories of Excellence Ion Channel Science and Therapeutics, Nice, France
| | - L Counillon
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark; and Université Côte d'Azur, CNRS, Laboratoire de Physiomédecine Moléculaire, LP2M, France, and Laboratories of Excellence Ion Channel Science and Therapeutics, Nice, France
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41
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Spatiotemporal pH Heterogeneity as a Promoter of Cancer Progression and Therapeutic Resistance. Cancers (Basel) 2019; 11:cancers11071026. [PMID: 31330859 PMCID: PMC6678451 DOI: 10.3390/cancers11071026] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 07/17/2019] [Accepted: 07/18/2019] [Indexed: 12/15/2022] Open
Abstract
Dysregulation of pH in solid tumors is a hallmark of cancer. In recent years, the role of altered pH heterogeneity in space, between benign and aggressive tissues, between individual cancer cells, and between subcellular compartments, has been steadily elucidated. Changes in temporal pH-related processes on both fast and slow time scales, including altered kinetics of bicarbonate-CO2 exchange and its effects on pH buffering and gradual, progressive changes driven by changes in metabolism, are further implicated in phenotypic changes observed in cancers. These discoveries have been driven by advances in imaging technologies. This review provides an overview of intra- and extracellular pH alterations in time and space reflected in cancer cells, as well as the available technology to study pH spatiotemporal heterogeneity.
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Benitez M, Tatapudy S, Liu Y, Barber DL, Nystul TG. Drosophila anion exchanger 2 is required for proper ovary development and oogenesis. Dev Biol 2019; 452:127-133. [PMID: 31071312 DOI: 10.1016/j.ydbio.2019.04.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 03/22/2019] [Accepted: 04/26/2019] [Indexed: 02/06/2023]
Abstract
Understanding how cell fate decisions are regulated is a central question in stem cell biology. Recent studies have demonstrated that intracellular pH (pHi) dynamics contribute to this process. Indeed, the pHi of cells within a tissue is not simply a consequence of chemical reactions in the cytoplasm and other cellular activity, but is actively maintained at a specific setpoint in each cell type. We found previously that the pHi of cells in the follicle stem cell (FSC) lineage in the Drosophila ovary increases progressively during differentiation from an average of 6.8 in the FSCs, to 7.0 in newly produced daughter cells, to 7.3 in more differentiated cells. Two major regulators of pHi in this lineage are Drosophila sodium-proton exchanger 2 (dNhe2) and a previously uncharacterized gene, CG8177, that is homologous to mammalian anion exchanger 2 (AE2). Based on this homology, we named the gene anion exchanger 2 (ae2). Here, we generated null alleles of ae2 and found that homozygous mutant flies are viable but have severe defects in ovary development and adult oogenesis. Specifically, we find that ae2 null flies have smaller ovaries, reduced fertility, and impaired follicle formation. In addition, we find that the follicle formation defect can be suppressed by a decrease in dNhe2 copy number and enhanced by the overexpression of dNhe2, suggesting that this phenotype is due to the dysregulation of pHi. These findings support the emerging idea that pHi dynamics regulate cell fate decisions and our studies provide new genetic tools to investigate the mechanisms by which this occurs.
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Affiliation(s)
- Marimar Benitez
- Departments of Anatomy and OB-GYN/RS, University of California, San Francisco, USA
| | - Sumitra Tatapudy
- Departments of Anatomy and OB-GYN/RS, University of California, San Francisco, USA
| | - Yi Liu
- Departments of Anatomy and OB-GYN/RS, University of California, San Francisco, USA
| | - Diane L Barber
- Department of Cell and Tissue Biology, University of California, San Francisco, USA
| | - Todd G Nystul
- Departments of Anatomy and OB-GYN/RS, University of California, San Francisco, USA.
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43
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Charafeddine RA, Cortopassi WA, Lak P, Tan R, McKenney RJ, Jacobson MP, Barber DL, Wittmann T. Tau repeat regions contain conserved histidine residues that modulate microtubule-binding in response to changes in pH. J Biol Chem 2019; 294:8779-8790. [PMID: 30992364 DOI: 10.1074/jbc.ra118.007004] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 04/13/2019] [Indexed: 12/20/2022] Open
Abstract
Tau, a member of the MAP2/tau family of microtubule-associated proteins, stabilizes and organizes axonal microtubules in healthy neurons. In neurodegenerative tauopathies, tau dissociates from microtubules and forms neurotoxic extracellular aggregates. MAP2/tau family proteins are characterized by three to five conserved, intrinsically disordered repeat regions that mediate electrostatic interactions with the microtubule surface. Here, we used molecular dynamics, microtubule-binding experiments, and live-cell microscopy, revealing that highly-conserved histidine residues near the C terminus of each microtubule-binding repeat are pH sensors that can modulate tau-microtubule interaction strength within the physiological intracellular pH range. We observed that at low pH (<7.5), these histidines are positively charged and interact with phenylalanine residues in a hydrophobic cleft between adjacent tubulin dimers. At higher pH (>7.5), tau deprotonation decreased binding to microtubules both in vitro and in cells. Electrostatic and hydrophobic characteristics of histidine were both required for tau-microtubule binding, as substitutions with constitutively and positively charged nonaromatic lysine or uncharged alanine greatly reduced or abolished tau-microtubule binding. Consistent with these findings, tau-microtubule binding was reduced in a cancer cell model with increased intracellular pH but was rapidly restored by decreasing the pH to normal levels. These results add detailed insights into the intracellular regulation of tau activity that may be relevant in both normal and pathological conditions.
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Affiliation(s)
- Rabab A Charafeddine
- From the Department of Cell and Tissue Biology, University of California San Francisco, San Francisco, California 94143
| | - Wilian A Cortopassi
- the Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California 94158, and
| | - Parnian Lak
- the Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California 94158, and
| | - Ruensern Tan
- the Department of Molecular and Cellular Biology, University of California Davis, Davis, California 95616
| | - Richard J McKenney
- the Department of Molecular and Cellular Biology, University of California Davis, Davis, California 95616
| | - Matthew P Jacobson
- the Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California 94158, and
| | - Diane L Barber
- From the Department of Cell and Tissue Biology, University of California San Francisco, San Francisco, California 94143
| | - Torsten Wittmann
- From the Department of Cell and Tissue Biology, University of California San Francisco, San Francisco, California 94143,
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45
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Xu M, Ma X, Wei T, Lu ZX, Ren B. In Situ Imaging of Live-Cell Extracellular pH during Cell Apoptosis with Surface-Enhanced Raman Spectroscopy. Anal Chem 2018; 90:13922-13928. [PMID: 30394732 DOI: 10.1021/acs.analchem.8b03193] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Extracellular pH (pHe) is an important regulating factor that determines many cellular processes, including proliferation, differentiation, and apoptosis. In our previous work, we developed 4-MPy (4-mercaptopyridine) modified Au nanoparticles as intracellular pH sensors based on surface-enhanced Raman spectroscopy (SERS). We herein modified a Au-nanoparticle-assembled solid SERS substrate with 4-MPy molecules for in situ pHe sensing during apoptosis. We found a more acidic extracellular environment of cancer cells than that of normal cells from the pH imaging. We then in situ investigated the temporal and spatial evolution of pHe of cancer cells after addition of transforming growth factor-β (TGF-β). The pHe showed a fast decrease at the beginning, followed by a slow decrease until the complete loss of cellular functions, and the pH values in and out of the cells became similar. This work shows that our SERS substrate combined with an in situ cell culture system is well suitable for in situ pHe sensing during cell processes and will be a promising technique for understanding more pHe-related biological and pathological issues.
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46
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Goult BT, Yan J, Schwartz MA. Talin as a mechanosensitive signaling hub. J Cell Biol 2018; 217:3776-3784. [PMID: 30254032 PMCID: PMC6219721 DOI: 10.1083/jcb.201808061] [Citation(s) in RCA: 163] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 09/12/2018] [Accepted: 09/17/2018] [Indexed: 12/15/2022] Open
Abstract
Cell adhesion to the extracellular matrix (ECM), mediated by transmembrane receptors of the integrin family, is exquisitely sensitive to biochemical, structural, and mechanical features of the ECM. Talin is a cytoplasmic protein consisting of a globular head domain and a series of α-helical bundles that form its long rod domain. Talin binds to the cytoplasmic domain of integrin β-subunits, activates integrins, couples them to the actin cytoskeleton, and regulates integrin signaling. Recent evidence suggests switch-like behavior of the helix bundles that make up the talin rod domains, where individual domains open at different tension levels, exerting positive or negative effects on different protein interactions. These results lead us to propose that talin functions as a mechanosensitive signaling hub that integrates multiple extracellular and intracellular inputs to define a major axis of adhesion signaling.
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Affiliation(s)
| | - Jie Yan
- Mechanobiology Institute, National University of Singapore, Singapore.,Department of Physics, National University of Singapore, Singapore.,Centre for Bioimaging Sciences, National University of Singapore, Singapore
| | - Martin A Schwartz
- Wellcome Trust Centre for Matrix Research, University of Manchester, Manchester, UK.,Yale Cardiovascular Research Center and Departments of Internal Medicine (Cardiology), Cell Biology, and Biomedical Engineering, Yale School of Medicine, New Haven, CT
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47
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Gough RE, Goult BT. The tale of two talins - two isoforms to fine-tune integrin signalling. FEBS Lett 2018; 592:2108-2125. [PMID: 29723415 PMCID: PMC6032930 DOI: 10.1002/1873-3468.13081] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 04/12/2018] [Accepted: 04/26/2018] [Indexed: 11/08/2022]
Abstract
Talins are cytoplasmic adapter proteins essential for integrin-mediated cell adhesion to the extracellular matrix. Talins control the activation state of integrins, link integrins to cytoskeletal actin, recruit numerous signalling molecules that mediate integrin signalling and coordinate recruitment of microtubules to adhesion sites via interaction with KANK (kidney ankyrin repeat-containing) proteins. Vertebrates have two talin genes, TLN1 and TLN2. Although talin1 and talin2 share 76% protein sequence identity (88% similarity), they are not functionally redundant, and the differences between the two isoforms are not fully understood. In this Review, we focus on the similarities and differences between the two talins in terms of structure, biochemistry and function, which hint at subtle differences in fine-tuning adhesion signalling.
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48
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Li S, Xiong N, Peng Y, Tang K, Bai H, Lv X, Jiang Y, Qin X, Yang H, Wu C, Zhou P, Liu Y. Acidic pHe regulates cytoskeletal dynamics through conformational integrin β1 activation and promotes membrane protrusion. Biochim Biophys Acta Mol Basis Dis 2018; 1864:2395-2408. [PMID: 29698684 DOI: 10.1016/j.bbadis.2018.04.019] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 04/02/2018] [Accepted: 04/19/2018] [Indexed: 12/15/2022]
Abstract
An acidic extracellular pH (pHe) in the tumor microenvironment has been suggested to facilitate tumor growth and metastasis. However, the molecular mechanisms by which tumor cells sense acidic signal to induce a transition to an aggressive phenotype remain elusive. Here, we showed that an acidic pHe (pH 6.5) stimulation resulted in protrusion and epithelial-mesenchymal transition (EMT) of cancer cells, which promoted migration and matrix degeneration. Using computational molecular dynamics simulations, we reported acidic pHe-induced opening of the Integrin dimers (α5β1) headpiece which indicated the activation of integrin. Moreover, acidic pHe promoted maturation of focal adhesions, temporal activation of Rho GTPases and microfilament reorganization through integrin β1-activated FAK signaling. Furthermore, mechanical balance of cytoskeleton (actin, tubulin and vimentin) contributed to acidic pHe-triggered protrusion and morphology change. Taken together, these findings revealed that integrin β1 could be a novel pH-regulated sensitive molecule which confers protrusion and malignant phenotype of cancer cells.
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Affiliation(s)
- Shun Li
- Department of Biophysics, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan, PR China; Center for Information in Biology, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan, PR China
| | - Niya Xiong
- Department of Biophysics, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan, PR China
| | - Yueting Peng
- Department of Biophysics, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan, PR China
| | - Kai Tang
- Department of Biophysics, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan, PR China
| | - Hongxia Bai
- Department of Biophysics, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan, PR China
| | - Xiaoying Lv
- Department of Biophysics, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan, PR China
| | - Ying Jiang
- Department of Biophysics, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan, PR China; Center for Information in Biology, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan, PR China
| | - Xiang Qin
- Department of Biophysics, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan, PR China; Center for Information in Biology, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan, PR China
| | - Hong Yang
- Department of Biophysics, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan, PR China; Center for Information in Biology, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan, PR China
| | - Chunhui Wu
- Department of Biophysics, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan, PR China; Center for Information in Biology, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan, PR China
| | - Peng Zhou
- Center for Information in Biology, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan, PR China
| | - Yiyao Liu
- Department of Biophysics, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan, PR China; Center for Information in Biology, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan, PR China.
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49
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Angelova MI, Bitbol AF, Seigneuret M, Staneva G, Kodama A, Sakuma Y, Kawakatsu T, Imai M, Puff N. pH sensing by lipids in membranes: The fundamentals of pH-driven migration, polarization and deformations of lipid bilayer assemblies. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:2042-2063. [PMID: 29501601 DOI: 10.1016/j.bbamem.2018.02.026] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 02/22/2018] [Accepted: 02/24/2018] [Indexed: 01/27/2023]
Abstract
Most biological molecules contain acido-basic groups that modulate their structure and interactions. A consequence is that pH gradients, local heterogeneities and dynamic variations are used by cells and organisms to drive or regulate specific biological functions including energetic metabolism, vesicular traffic, migration and spatial patterning of tissues in development. While the direct or regulatory role of pH in protein function is well documented, the role of hydrogen and hydroxyl ions in modulating the properties of lipid assemblies such as bilayer membranes is only beginning to be understood. Here, we review approaches using artificial lipid vesicles that have been instrumental in providing an understanding of the influence of pH gradients and local variations on membrane vectorial motional processes: migration, membrane curvature effects promoting global or local deformations, crowding generation by segregative polarization processes. In the case of pH induced local deformations, an extensive theoretical framework is given and an application to a specific biological issue, namely the structure and stability of mitochondrial cristae, is described. This article is part of a Special Issue entitled: Emergence of Complex Behavior in Biomembranes edited by Marjorie Longo.
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Affiliation(s)
- Miglena I Angelova
- Sorbonne University, Faculty of Science and Engineering, UFR 925 Physics, Paris F-75005, France; University Paris Diderot - Paris 7, Sorbonne Paris Cité, Laboratory Matière et Systèmes Complexes (MSC) UMR 7057 CNRS, Paris F-75013, France.
| | - Anne-Florence Bitbol
- Sorbonne University, Faculty of Science and Engineering, Laboratory Jean Perrin, UMR 8237 CNRS, Paris F-75005, France
| | - Michel Seigneuret
- University Paris Diderot - Paris 7, Sorbonne Paris Cité, Laboratory Matière et Systèmes Complexes (MSC) UMR 7057 CNRS, Paris F-75013, France
| | - Galya Staneva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Atsuji Kodama
- Department of Physics, Tohoku University, Aoba, Sendai 980-8578, Japan
| | - Yuka Sakuma
- Department of Physics, Tohoku University, Aoba, Sendai 980-8578, Japan
| | | | - Masayuki Imai
- Department of Physics, Tohoku University, Aoba, Sendai 980-8578, Japan
| | - Nicolas Puff
- Sorbonne University, Faculty of Science and Engineering, UFR 925 Physics, Paris F-75005, France; University Paris Diderot - Paris 7, Sorbonne Paris Cité, Laboratory Matière et Systèmes Complexes (MSC) UMR 7057 CNRS, Paris F-75013, France
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50
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Mboge MY, Mahon BP, McKenna R, Frost SC. Carbonic Anhydrases: Role in pH Control and Cancer. Metabolites 2018; 8:E19. [PMID: 29495652 PMCID: PMC5876008 DOI: 10.3390/metabo8010019] [Citation(s) in RCA: 178] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 02/08/2018] [Accepted: 02/22/2018] [Indexed: 02/07/2023] Open
Abstract
The pH of the tumor microenvironment drives the metastatic phenotype and chemotherapeutic resistance of tumors. Understanding the mechanisms underlying this pH-dependent phenomenon will lead to improved drug delivery and allow the identification of new therapeutic targets. This includes an understanding of the role pH plays in primary tumor cells, and the regulatory factors that permit cancer cells to thrive. Over the last decade, carbonic anhydrases (CAs) have been shown to be important mediators of tumor cell pH by modulating the bicarbonate and proton concentrations for cell survival and proliferation. This has prompted an effort to inhibit specific CA isoforms, as an anti-cancer therapeutic strategy. Of the 12 active CA isoforms, two, CA IX and XII, have been considered anti-cancer targets. However, other CA isoforms also show similar activity and tissue distribution in cancers and have not been considered as therapeutic targets for cancer treatment. In this review, we consider all the CA isoforms and their possible role in tumors and their potential as targets for cancer therapy.
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Affiliation(s)
- Mam Y Mboge
- University of Florida, College of Medicine, Department of Biochemistry and Molecular Biology, P.O. Box 100245, Gainesville, FL 32610, USA.
| | - Brian P Mahon
- University of Florida, College of Medicine, Department of Biochemistry and Molecular Biology, P.O. Box 100245, Gainesville, FL 32610, USA.
| | - Robert McKenna
- University of Florida, College of Medicine, Department of Biochemistry and Molecular Biology, P.O. Box 100245, Gainesville, FL 32610, USA.
| | - Susan C Frost
- University of Florida, College of Medicine, Department of Biochemistry and Molecular Biology, P.O. Box 100245, Gainesville, FL 32610, USA.
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