title: Interplay between a cytosolic and a cell surface carbonic anhydrase in pH homeostasis and acid tolerance ofLeishmania.
abstract: Leishmaniaparasites have evolved to endure the acidic phagolysosomal environment within host macrophages. HowLeishmaniacells maintain near-neutral intracellular pH and proliferate in such a proton-rich mileu remains poorly understood. We report here that, in order to thrive in acidic conditions,Leishmania majorrelies on a cytosolic and a cell surface carbonic anhydrase, LmCA1 and LmCA2, respectively. Upon exposure to acidic medium, the intracellular pH of the LmCA1+/-, LmCA2+/-and LmCA1+/-:LmCA2+/-mutant strains dropped by varying extents that led to cell cycle delay, growth retardation and morphological abnormalities. Intracellular acidosis and growth defects of the mutant strains could be reverted by genetic complementation or supplementation with bicarbonate. When J774A.1 macrophages were infected with the mutant strains, they exhibited much lower intracellular parasite burdens than their wild-type counterparts. However, these differences in intracellular parasite burden between the wild-type and mutant strains were abrogated if, before infection, the macrophages were treated with chloroquine to alkalize their phagolysosomes. Taken together, our results demonstrate that haploinsufficiency of LmCA1 and/or LmCA2 renders the parasite acid-susceptible, thereby unravelling a carbonic anhydrase-mediated pH homeostatic circuit inLeishmaniacells.
authors.affiliation: Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur-741246, West Bengal, India.
authors.forename: Dhiman Sankar
authors.identifier: 0000-0002-8442-3507
authors.initials: DS
authors.lastname: Pal
authors.affiliation: Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur-741246, West Bengal, India.
authors.forename: Mazharul
authors.identifier: 0000-0002-3124-4548
authors.initials: M
authors.lastname: Abbasi
authors.affiliation: Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur-741246, West Bengal, India.
authors.forename: Dipon Kumar
authors.identifier: 0000-0002-1065-971X
authors.initials: DK
authors.lastname: Mondal
authors.affiliation: Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur-741246, West Bengal, India.
authors.forename: Binitha Anu
authors.identifier: 0000-0002-2162-7828
authors.initials: BA
authors.lastname: Varghese
authors.affiliation: Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur-741246, West Bengal, India.
authors.forename: Ritama
authors.identifier: 0000-0002-6748-9088
authors.initials: R
authors.lastname: Paul
authors.affiliation: Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur-741246, West Bengal, India.
authors.forename: Shalini
authors.identifier: 0000-0002-2231-2043
authors.initials: S
authors.lastname: Singh
authors.affiliation: Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur-741246, West Bengal, India rupakdatta@iiserkol.ac.in.
authors.forename: Rupak
authors.identifier: 0000-0003-1820-9251
authors.initials: R
authors.lastname: Datta
mesh_terms: D000138:Acidosis / Q000378:metabolism / Q000473:pathology; D000143:Acids / Q000494:pharmacology*; D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D002256:Carbonic Anhydrases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002453:Cell Cycle / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000201:enzymology*; D003600:Cytosol / Q000187:drug effects / Q000201:enzymology*; D018390:Gene Targeting; D006706:Homeostasis / Q000187:drug effects; D059765:Homologous Recombination / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D018320:Leishmania major / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D008247:Lysosomes / Q000187:drug effects / Q000378:metabolism; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D010271:Parasites / Q000187:drug effects / Q000201:enzymology; D021381:Protein Transport / Q000187:drug effects; D016415:Sequence Alignment
chemical_list: D000143:Acids; D002256:Carbonic Anhydrases
keywords: Carbonic anhydrase; Leishmania; pH