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dc.contributor.author
Barrera, Patricia Andrea
dc.contributor.author
Skorka, Christopher
dc.contributor.author
Boktor, Michael
dc.contributor.author
Dave, Noopur
dc.contributor.author
Jimenez, Veronica
dc.date.available
2021-09-21T13:09:12Z
dc.date.issued
2020-01
dc.identifier.citation
Barrera, Patricia Andrea; Skorka, Christopher; Boktor, Michael; Dave, Noopur; Jimenez, Veronica; A Novel Calcium-Activated Potassium Channel Controls Membrane Potential and Intracellular pH in Trypanosoma cruzi; Frontiers Media S.A.; Frontiers in Cellular and Infection Microbiology; 9; 1-2020; 1-17
dc.identifier.issn
2235-2988
dc.identifier.uri
http://hdl.handle.net/11336/140980
dc.description.abstract
Trypanosoma cruzi develops in environments where nutrient availability, osmolarity, ionic concentrations, and pH undergo significant changes. The ability to adapt and respond to such conditions determines the survival and successful transmission of T. cruzi. Ion channels play fundamental roles in controlling physiological parameters that ensure cell homeostasis by rapidly triggering compensatory mechanisms. Combining molecular, cellular and electrophysiological approaches we have identified and characterized the expression and function of a novel calcium-activated potassium channel (TcCAKC). This channel resides in the plasma membrane of all 3 life stages of T. cruzi and shares structural features with other potassium channels. We expressed TcCAKC in Xenopus laevis oocytes and established its biophysical properties by two-electrode voltage clamp. Oocytes expressing TcCAKC showed a significant increase in inward currents after addition of calcium ionophore ionomycin or thapsigargin. These responses were abolished by EGTA suggesting that TcCAKC activation is dependent of extracellular calcium. This activation causes an increase in current and a negative shift in reversal potential that is blocked by barium. As predicted, a single point mutation in the selectivity filter (Y313A) completely abolished the activity of the channels, confirming its potassium selective nature. We have generated knockout parasites deleting one or both alleles of TcCAKC. These parasite strains showed impaired growth, decreased production of trypomastigotes and slower intracellular replication, pointing to an important role of TcCAKC in regulating infectivity. To understand the cellular mechanisms underlying these phenotypic defects, we used fluorescent probes to evaluate intracellular membrane potential, pH, and intracellular calcium. Epimastigotes lacking the channel had significantly lower cytosolic calcium, hyperpolarization, changes in intracellular pH, and increased rate of proton extrusion. These results are in agreement with previous reports indicating that, in trypanosomatids, membrane potential and intracellular pH maintenance are linked. Our work shows TcCAKC is a novel potassium channel that contributes to homeostatic regulation of important physiological processes in T. cruzi and provides new avenues to explore the potential of ion channels as targets for drug development against protozoan parasites.
dc.format
application/pdf
dc.language.iso
eng
dc.publisher
Frontiers Media S.A.
dc.rights
info:eu-repo/semantics/openAccess
dc.rights.uri
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.subject
ELECTROPHYSIOLOGY
dc.subject
INTRACELLULAR CALCIUM
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MEMBRANE POTENTIAL
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POTASSIUM CHANNEL
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TRYPANOSOMA CRUZI
dc.subject.classification
Bioquímica y Biología Molecular
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Ciencias Biológicas
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CIENCIAS NATURALES Y EXACTAS
dc.title
A Novel Calcium-Activated Potassium Channel Controls Membrane Potential and Intracellular pH in Trypanosoma cruzi
dc.type
info:eu-repo/semantics/article
dc.type
info:ar-repo/semantics/artículo
dc.type
info:eu-repo/semantics/publishedVersion
dc.date.updated
2021-04-28T20:08:30Z
dc.journal.volume
9
dc.journal.pagination
1-17
dc.journal.pais
Suiza
dc.description.fil
Fil: Barrera, Patricia Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; Argentina
dc.description.fil
Fil: Skorka, Christopher. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología; Argentina
dc.description.fil
Fil: Boktor, Michael. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología; Argentina
dc.description.fil
Fil: Dave, Noopur. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología; Argentina
dc.description.fil
Fil: Jimenez, Veronica. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología; Argentina
dc.journal.title
Frontiers in Cellular and Infection Microbiology
dc.relation.alternativeid
info:eu-repo/semantics/altIdentifier/url/https://www.frontiersin.org/articles/10.3389/fcimb.2019.00464/full
dc.relation.alternativeid
info:eu-repo/semantics/altIdentifier/doi/https://doi.org/10.3389/fcimb.2019.00464
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