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Docampo R. Advances in the cellular biology, biochemistry, and molecular biology of acidocalcisomes. Microbiol Mol Biol Rev 2024; 88:e0004223. [PMID: 38099688 PMCID: PMC10966946 DOI: 10.1128/mmbr.00042-23] [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] [Indexed: 02/04/2024] Open
Abstract
SUMMARYAcidocalcisomes are organelles conserved during evolution and closely related to the so-called volutin granules of bacteria and archaea, to the acidocalcisome-like vacuoles of yeasts, and to the lysosome-related organelles of animal species. All these organelles have in common their acidity and high content of polyphosphate and calcium. They are characterized by a variety of functions from storage of phosphorus and calcium to roles in Ca2+ signaling, osmoregulation, blood coagulation, and inflammation. They interact with other organelles through membrane contact sites or by fusion, and have several enzymes, pumps, transporters, and channels.
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Affiliation(s)
- Roberto Docampo
- Department of Cellular Biology, Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
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2
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Pérez-Gordones MC, Ramírez-Iglesias JR, Benaim G, Mendoza M. Molecular, immunological, and physiological evidences of a sphingosine-activated plasma membrane Ca 2+-channel in Trypanosoma equiperdum. Parasitol Res 2024; 123:166. [PMID: 38506929 DOI: 10.1007/s00436-024-08188-z] [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: 10/18/2023] [Accepted: 03/14/2024] [Indexed: 03/22/2024]
Abstract
The hemoparasite Trypanosoma equiperdum belongs to the Trypanozoon subgenus and includes several species that are pathogenic to animals and humans in tropical and subtropical areas across the world. As with all eukaryotic organisms, Ca2+ is essential for these parasites to perform cellular processes thus ensuring their survival across their life cycle. Despite the established paradigm to study proteins related to Ca2+ homeostasis as potential drug targets, so far little is known about Ca2+ entry into trypanosomes. Therefore, in the present study, the presence of a plasma membrane Ca2+-channel in T. equiperdum (TeCC), activated by sphingosine and inhibited by verapamil, is described. The TeCC was cloned and analyzed using bioinformatic resources, which confirmed the presence of several domains, motifs, and a topology similar to the Ca2+ channels found in higher eukaryotes. Biochemical and confocal microscopy assays using antibodies raised against an internal region of human L-type Ca2+ channels indicate the presence of a protein with similar predicted molar mass to the sequence analyzed, located at the plasma membrane of T. equiperdum. Physiological assays based on Fura-2 signals and Mn2+ quenching performed on whole parasites showed a unidirectional Ca2+ entry, which is activated by sphingosine and blocked by verapamil, with the distinctive feature of insensitivity to nifedipine and Bay K 8644. This suggests a second Ca2+ entry for T. equiperdum, different from the store-operated Ca2+ entry (SOCE) previously described. Moreover, the evidence presented here for the TeCC indicates molecular and pharmacological differences with their mammal counterparts, which deserve further studies to evaluate the potential of this channel as a drug target.
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Affiliation(s)
- M C Pérez-Gordones
- Instituto de Biología Experimental (IBE), Universidad Central de Venezuela (UCV), Caracas, Venezuela.
| | - J R Ramírez-Iglesias
- Group of Emerging Diseases, Epidemiology & Biodiversity, Master School of Biomedicine, Health Sciences Faculty, Universidad Internacional SEK (UISEK), Quito, Ecuador
| | - G Benaim
- Instituto de Biología Experimental (IBE), Universidad Central de Venezuela (UCV), Caracas, Venezuela
- Instituto de Estudios Avanzados (IDEA), Caracas, Venezuela
| | - M Mendoza
- Centro de Estudios Biomédicos y Veterinarios, Instituto de Estudios Científicos y Tecnológicos (IDECYT), Universidad Nacional Experimental Simón Rodríguez, Caracas, Venezuela
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3
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Mantilla G, Peréz-Gordones MC, Cisneros-Montufar S, Benaim G, Navarro JC, Mendoza M, Ramírez-Iglesias JR. Structural Analysis and Diversity of Calmodulin-Binding Domains in Membrane and Intracellular Ca2+-ATPases. J Membr Biol 2022; 256:159-174. [PMID: 36454258 DOI: 10.1007/s00232-022-00275-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 11/11/2022] [Indexed: 12/03/2022]
Abstract
The plasma membrane and autoinhibited Ca2+-ATPases contribute to the Ca2+ homeostasis in a wide variety of organisms. The enzymatic activity of these pumps is stimulated by calmodulin, which interacts with the target protein through the calmodulin-binding domain (CaMBD). Most information about this region is related to all calmodulin modulated proteins, which indicates general chemical properties and there is no established relation between Ca2+ pump sequences and taxonomic classification. Thus, the aim of this study was to perform an in silico analysis of the CaMBD from several Ca2+-ATPases, in order to determine their diversity and to detect specific patterns and amino acid selection in different species. Patterns related to potential and confirmed CaMBD were detected using sequences retrieved from the literature. The occurrence of these patterns was determined across 120 sequences from 17 taxonomical classes, which were analyzed by a phylogenetic tree to establish phylogenetic groups. Predicted physicochemical characteristics including hydropathy and net charge were calculated for each group of sequences. 22 Ca2+-ATPases sequences from animals, unicellular eukaryotes, and plants were retrieved from bioinformatic databases. These sequences allow us to establish the Patterns 1(GQILWVRGLTRLQTQ), 3(KNPSLEALQRW), and 4(SRWRRLQAEHVKK), which are present at the beginning of putative CaMBD of metazoan, parasites, and land plants. A pattern 2 (IRVVNAFR) was consistently found at the end of most analyzed sequences. The amino acid preference in the CaMBDs changed depending on the phylogenetic groups, with predominance of several aliphatic and charged residues, to confer amphiphilic properties. The results here displayed show a conserved mechanism to contribute to the Ca2+ homeostasis across evolution and may help to detect putative CaMBDs.
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Affiliation(s)
- Génesis Mantilla
- Research Group of Emerging and Neglected Diseases, Ecoepidemiology and Biodiversity. Health Sciences Faculty, Universidad Internacional SEK (UISEK), Quito, Ecuador
- Faculty of Engineering and Applied Sciences, Universidad Internacional SEK (UISEK), Quito, Ecuador
| | - María C Peréz-Gordones
- Instituto de Biología Experimental (IBE), Universidad Central de Venezuela (UCV), Caracas, Venezuela
| | - Soledad Cisneros-Montufar
- Research Group of Emerging and Neglected Diseases, Ecoepidemiology and Biodiversity. Health Sciences Faculty, Universidad Internacional SEK (UISEK), Quito, Ecuador
- Faculty of Engineering and Applied Sciences, Universidad Internacional SEK (UISEK), Quito, Ecuador
| | - Gustavo Benaim
- Instituto de Biología Experimental (IBE), Universidad Central de Venezuela (UCV), Caracas, Venezuela
- Instituto de Estudios Avanzados (IDEA), Caracas, Venezuela
| | - Juan-Carlos Navarro
- Research Group of Emerging and Neglected Diseases, Ecoepidemiology and Biodiversity. Health Sciences Faculty, Universidad Internacional SEK (UISEK), Quito, Ecuador
- Program of Master in Biomedicine, Health Sciences Faculty, Universidad Internacional SEK (UISEK), Quito, Ecuador
| | - Marta Mendoza
- Centro de Estudios Biomédicos y Veterinarios, Instituto de Estudios Científicos y Tecnológicos (IDECYT), Universidad Nacional Experimental Simón Rodríguez, Caracas, Venezuela
| | - José R Ramírez-Iglesias
- Research Group of Emerging and Neglected Diseases, Ecoepidemiology and Biodiversity. Health Sciences Faculty, Universidad Internacional SEK (UISEK), Quito, Ecuador.
- Program of Master in Biomedicine, Health Sciences Faculty, Universidad Internacional SEK (UISEK), Quito, Ecuador.
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Ren D, Liu R, Yan X, Zhang Q, Zeng X, Yuan X. Intensive stretch-activated CRT-PMCA1 feedback loop promoted apoptosis of myoblasts through Ca 2+ overloading. Apoptosis 2022; 27:929-945. [PMID: 35976579 DOI: 10.1007/s10495-022-01759-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/01/2022] [Indexed: 11/29/2022]
Abstract
Mechanical stretch exerted pro-apoptotic effect on myoblasts, the mechanism of which is currently unknown. Intracellular Ca2+ accumulation has been implicated in stretch-induced apoptosis. calreticulin (CRT) and plasma membrane Ca2+ transporting ATPase 1 (PMCA1) are two critical components of Ca2+ signaling system participating in intracellular Ca2+ homeostasis. In this study, we explored the contribution of CRT and PMCA1 in mediating stretch-induced Ca2+ accumulation and apoptosis of myoblasts. Stretching stimuli elevated level of CRT while inhibited activity of PMCA1. Moreover, there were bidirectional regulations between CRT and PMCA1, which formed the positive feedback loop leading to continuous increment of CRT level and repression of PMCA1 activity, in stretched myoblasts. Specifically, increased CRT level inhibited PMCA1 activity via suppressing Calmodulin (CaM), while reduced PMCA1 activity promoted CRT expression through activating p38MAPK pathway. Thus, the CRT-CaM-PMCA1 and PMCA1-p38MAPK-CRT pathways constituted a close cycle comprising CRT, PMCA1, CaM and p38MAPK. Inhibition of both CaM and p38MAPK affected the other three factors in stretched myoblasts. Circulation of the vicious cycle resulted in escalated Ca2+ overloading in myoblasts under continuous stretching stimuli. CRT knock-down, PMCA1 overexpression, and p38MAPK inhibition all attenuated the raised intracellular Ca2+ level and ameliorated myoblast apoptosis in the stretching environment. Conversely, CRT overexpression, PMCA1 knock-down, and CaM inhibition all aggravated stretch-induced Ca2+ overloading and myoblast apoptosis. A positive feedback loop between CRT and PMCA1 was activated in stretched myoblasts, which contributed to intracellular Ca2+ accumulation and resultant myoblast apoptosis.
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Affiliation(s)
- Dapeng Ren
- Department of Stomatology Medical Center, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Central Laboratory of Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Department of Orthodontics, School of Stomatology, Qingdao University, Qingdao, China
| | - Ran Liu
- Department of Stomatology Medical Center, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Central Laboratory of Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China
| | - Xiao Yan
- Department of Stomatology Medical Center, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Central Laboratory of Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Department of Orthodontics, School of Stomatology, Qingdao University, Qingdao, China
| | - Qiang Zhang
- Department of Stomatology Medical Center, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Central Laboratory of Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Department of Orthodontics, School of Stomatology, Qingdao University, Qingdao, China
| | - Xuemin Zeng
- Department of Stomatology Medical Center, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Central Laboratory of Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Department of Orthodontics, School of Stomatology, Qingdao University, Qingdao, China
| | - Xiao Yuan
- Department of Stomatology Medical Center, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China. .,Central Laboratory of Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China. .,Department of Orthodontics, School of Stomatology, Qingdao University, Qingdao, China.
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Sharma A, Ramena GT, Elble RC. Advances in Intracellular Calcium Signaling Reveal Untapped Targets for Cancer Therapy. Biomedicines 2021; 9:1077. [PMID: 34572262 PMCID: PMC8466575 DOI: 10.3390/biomedicines9091077] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/15/2021] [Accepted: 07/18/2021] [Indexed: 02/07/2023] Open
Abstract
Intracellular Ca2+ distribution is a tightly regulated process. Numerous Ca2+ chelating, storage, and transport mechanisms are required to maintain normal cellular physiology. Ca2+-binding proteins, mainly calmodulin and calbindins, sequester free intracellular Ca2+ ions and apportion or transport them to signaling hubs needing the cations. Ca2+ channels, ATP-driven pumps, and exchangers assist the binding proteins in transferring the ions to and from appropriate cellular compartments. Some, such as the endoplasmic reticulum, mitochondria, and lysosomes, act as Ca2+ repositories. Cellular Ca2+ homeostasis is inefficient without the active contribution of these organelles. Moreover, certain key cellular processes also rely on inter-organellar Ca2+ signaling. This review attempts to encapsulate the structure, function, and regulation of major intracellular Ca2+ buffers, sensors, channels, and signaling molecules before highlighting how cancer cells manipulate them to survive and thrive. The spotlight is then shifted to the slow pace of translating such research findings into anticancer therapeutics. We use the PubMed database to highlight current clinical studies that target intracellular Ca2+ signaling. Drug repurposing and improving the delivery of small molecule therapeutics are further discussed as promising strategies for speeding therapeutic development in this area.
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Affiliation(s)
- Aarushi Sharma
- Department of Pharmacology and Simmons Cancer Institute, Southern Illinois University School of Medicine, Springfield, IL 62702, USA;
| | - Grace T. Ramena
- Department of Aquaculture, University of Arkansas, Pine Bluff, AR 71601, USA;
| | - Randolph C. Elble
- Department of Pharmacology and Simmons Cancer Institute, Southern Illinois University School of Medicine, Springfield, IL 62702, USA;
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Benaim G, Paniz-Mondolfi AE, Sordillo EM, Martinez-Sotillo N. Disruption of Intracellular Calcium Homeostasis as a Therapeutic Target Against Trypanosoma cruzi. Front Cell Infect Microbiol 2020; 10:46. [PMID: 32133302 PMCID: PMC7040492 DOI: 10.3389/fcimb.2020.00046] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 01/24/2020] [Indexed: 12/15/2022] Open
Abstract
There is no effective cure for Chagas disease, which is caused by infection with the arthropod-borne parasite, Trypanosoma cruzi. In the search for new drugs to treat Chagas disease, potential therapeutic targets have been identified by exploiting the differences between the mechanisms involved in intracellular Ca2+ homeostasis, both in humans and in trypanosomatids. In the trypanosomatid, intracellular Ca2+ regulation requires the concerted action of three intracellular organelles, the endoplasmic reticulum, the single unique mitochondrion, and the acidocalcisomes. The single unique mitochondrion and the acidocalcisomes also play central roles in parasite bioenergetics. At the parasite plasma membrane, a Ca2+-−ATPase (PMCA) with significant differences from its human counterpart is responsible for Ca2+ extrusion; a distinctive sphingosine-activated Ca2+ channel controls Ca2+ entrance to the parasite interior. Several potential anti-trypansosomatid drugs have been demonstrated to modulate one or more of these mechanisms for Ca2+ regulation. The antiarrhythmic agent amiodarone and its derivatives have been shown to exert trypanocidal effects through the disruption of parasite Ca2+ homeostasis. Similarly, the amiodarone-derivative dronedarone disrupts Ca2+ homeostasis in T. cruzi epimastigotes, collapsing the mitochondrial membrane potential (ΔΨm), and inducing a large increase in the intracellular Ca2+ concentration ([Ca2+]i) from this organelle and from the acidocalcisomes in the parasite cytoplasm. The same general mechanism has been demonstrated for SQ109, a new anti-tuberculosis drug with potent trypanocidal effect. Miltefosine similarly induces a large increase in the [Ca2+]i acting on the sphingosine-activated Ca2+ channel, the mitochondrion and acidocalcisomes. These examples, in conjunction with other evidence we review herein, strongly support targeting Ca2+ homeostasis as a strategy against Chagas disease.
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Affiliation(s)
- Gustavo Benaim
- Instituto de Estudios Avanzados, Caracas, Venezuela.,Facultad de Ciencias, Instituto de Biología Experimental, Universidad Central de Venezuela, Caracas, Venezuela
| | - Alberto E Paniz-Mondolfi
- Instituto de Estudios Avanzados, Caracas, Venezuela.,Department of Pathology, Molecular, and Cell-Based Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Emilia Mia Sordillo
- Department of Pathology, Molecular, and Cell-Based Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States.,Institute for Health Sciences, Mount Sinai St. Luke's & Mount Sinai West, New York, NY, United States
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Ramakrishnan S, Docampo R. Membrane Proteins in Trypanosomatids Involved in Ca 2+ Homeostasis and Signaling. Genes (Basel) 2018; 9:E304. [PMID: 29921754 PMCID: PMC6027440 DOI: 10.3390/genes9060304] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 06/11/2018] [Accepted: 06/14/2018] [Indexed: 01/10/2023] Open
Abstract
Calcium ion (Ca2+) serves as a second messenger for a variety of cell functions in trypanosomes. Several proteins in the plasma membrane, acidocalcisomes, endoplasmic reticulum, and mitochondria are involved in its homeostasis and in cell signaling roles. The plasma membrane has a Ca2+ channel for its uptake and a plasma membrane-type Ca2+-ATPase (PMCA) for its efflux. A similar PMCA is also located in acidocalcisomes, acidic organelles that are the primary Ca2+ store and that possess an inositol 1,4,5-trisphosphate receptor (IP₃R) for Ca2+ efflux. Their mitochondria possess a mitochondrial calcium uniporter complex (MCUC) for Ca2+ uptake and a Ca2+/H⁺ exchanger for Ca2+ release. The endoplasmic reticulum has a sarcoplasmic-endoplasmic reticulum-type Ca2+-ATPase (SERCA) for Ca2+ uptake but no Ca2+ release mechanism has been identified. Additionally, the trypanosomatid genomes contain other membrane proteins that could potentially bind calcium and await further characterization.
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Affiliation(s)
- Srinivasan Ramakrishnan
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA.
| | - Roberto Docampo
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA.
- Department of Cellular Biology and Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA.
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Identification and characterization of a calmodulin binding domain in the plasma membrane Ca 2+-ATPase from Trypanosoma equiperdum. Mol Biochem Parasitol 2018; 222:51-60. [PMID: 29752964 DOI: 10.1016/j.molbiopara.2018.04.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 04/19/2018] [Accepted: 04/23/2018] [Indexed: 02/01/2023]
Abstract
The plasma membrane Ca2+-ATPase (PMCA) from trypanosomatids lacks a classical calmodulin (CaM) binding domain, although CaM stimulated activities have been detected by biochemical assays. Recently we proposed that the Trypanosoma equiperdum CaM-sensitive PMCA (TePMCA) contains a potential 1-18 CaM-binding motif at the C-terminal region of the pump. In the present study, we evaluated the potential CaM-binding motifs using CaM from Trypanosoma cruzi and either the recombinant full length TePMCA C-terminal sequence (P14) or synthetic peptides comprising different regions of the C-terminal domain. We demonstrated that P14 and a synthetic peptide corresponding to residues 1037-1062 (which contains the predicted 1-18 binding motif) competed efficiently for binding to TcCaM, exhibiting similar IC50s of 200 nM. A stable complex of this peptide and TcCaM was formed in the presence of Ca2+, as determined by native-polyacrylamide gel electrophoresis. A predicted structure obtained by molecular docking showed an interaction of the 1-18 binding motif with the Ca2+/CaM complex. Moreover, when the peptide was incubated with CaM and Ca2+, a blue shift in the tryptophan fluorescence spectrum (from 350 to 329 nm) was observed. Substitutions at W1039 and F1056, strongly decreased both CaM-peptide interaction and the complex assembly. Our results demonstrated the presence of a functional 1-18 motif at the TePMCA C-terminal domain. Furthermore, on the basis of spectrofluorometric assays and the resulting structure modeled by docking we propose that the L1042 and W1060 residues might also participate as anchors to form a 1-4-18-22 motif.
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