{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,14]],"date-time":"2026-04-14T02:30:38Z","timestamp":1776133838461,"version":"3.50.1"},"update-to":[{"DOI":"10.1371\/journal.ppat.1010139","type":"new_version","label":"New version","source":"publisher","updated":{"date-parts":[[2022,5,17]],"date-time":"2022-05-17T00:00:00Z","timestamp":1652745600000}}],"reference-count":53,"publisher":"Public Library of Science (PLoS)","issue":"5","license":[{"start":{"date-parts":[[2022,5,5]],"date-time":"2022-05-05T00:00:00Z","timestamp":1651708800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000060","name":"National Institute of Allergy and Infectious Diseases","doi-asserted-by":"publisher","award":["R01AI046675"],"award-info":[{"award-number":["R01AI046675"]}],"id":[{"id":"10.13039\/100000060","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.plospathogens.org"],"crossmark-restriction":false},"short-container-title":["PLoS Pathog"],"abstract":"<jats:p>\n                    The\n                    <jats:italic>Toxoplasma gondii<\/jats:italic>\n                    lytic cycle is a repetition of host cell invasion, replication, egress, and re-invasion into the next host cell. While the molecular players involved in egress have been studied in greater detail in recent years, the signals and pathways for triggering egress from the host cell have not been fully elucidated. A perforin-like protein, PLP1, has been shown to be necessary for permeabilizing the parasitophorous vacuole (PV) membrane or exit from the host cell.\n                    <jats:italic>In vitro<\/jats:italic>\n                    studies indicated that PLP1 is most active in acidic conditions, and indirect evidence using superecliptic pHluorin indicated that the PV pH drops prior to parasite egress. Using ratiometric pHluorin, a GFP variant that responds to changes in pH with changes in its bimodal excitation spectrum peaks, allowed us to directly measure the pH in the PV prior to and during egress by live-imaging microscopy. A statistically significant change was observed in PV pH during ionomycin or zaprinast induced egress in both wild-type RH and \u0394\n                    <jats:italic>plp1<\/jats:italic>\n                    vacuoles compared to DMSO-treated vacuoles. Interestingly, if parasites are chemically paralyzed, a pH drop is still observed in RH but not in \u0394\n                    <jats:italic>plp1<\/jats:italic>\n                    tachyzoites. This indicates that the pH drop is dependent on the presence of PLP1 or motility. Efforts to determine transporters, exchangers, or pumps that could contribute to the drop in PV pH identified two formate-nitrite transporters (FNTs). Auxin induced conditional knockdown and knockouts of FNT1 and FNT2 reduced the levels of lactate and pyruvate released by the parasites and lead to an abatement of vacuolar acidification. While additional transporters and molecules are undoubtedly involved, we provide evidence of a definitive reduction in vacuolar pH associated with induced and natural egress and characterize two transporters that contribute to the acidification.\n                  <\/jats:p>","DOI":"10.1371\/journal.ppat.1010139","type":"journal-article","created":{"date-parts":[[2022,5,5]],"date-time":"2022-05-05T14:07:05Z","timestamp":1651759625000},"page":"e1010139","update-policy":"https:\/\/doi.org\/10.1371\/journal.ppat.corrections_policy","source":"Crossref","is-referenced-by-count":9,"title":["Toxoplasma gondii excretion of glycolytic products is associated with acidification of the parasitophorous vacuole during parasite egress"],"prefix":"10.1371","volume":"18","author":[{"given":"My-Hang","family":"Huynh","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6859-8895","authenticated-orcid":true,"given":"Vern B.","family":"Carruthers","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"340","published-online":{"date-parts":[[2022,5,5]]},"reference":[{"key":"ppat.1010139.ref001","doi-asserted-by":"crossref","first-page":"579","DOI":"10.1146\/annurev-micro-020518-120235","article-title":"Signaling Cascades Governing Entry into and Exit from Host Cells by Toxoplasma gondii","volume":"73","author":"H Bisio","year":"2019","journal-title":"Annu Rev Microbiol"},{"issue":"45","key":"ppat.1010139.ref002","doi-asserted-by":"crossref","first-page":"26914","DOI":"10.1074\/jbc.M115.652511","article-title":"Calcium Signaling throughout the Toxoplasma gondii Lytic Cycle: A STUDY USING GENETICALLY ENCODED CALCIUM INDICATORS","volume":"290","author":"L Borges-Pereira","year":"2015","journal-title":"J Biol Chem"},{"issue":"11 Pt B","key":"ppat.1010139.ref003","doi-asserted-by":"crossref","first-page":"1846","DOI":"10.1016\/j.bbamcr.2018.08.004","article-title":"Calcium signaling and the lytic cycle of the Apicomplexan parasite Toxoplasma gondii","volume":"1865","author":"MA Hortua Triana","year":"2018","journal-title":"Biochim Biophys Acta Mol Cell Res"},{"key":"ppat.1010139.ref004","doi-asserted-by":"crossref","first-page":"102337","DOI":"10.1016\/j.ceca.2020.102337","article-title":"The role of potassium and host calcium signaling in Toxoplasma gondii egress","volume":"94","author":"SA Vella","year":"2021","journal-title":"Cell Calcium"},{"issue":"3","key":"ppat.1010139.ref005","doi-asserted-by":"crossref","first-page":"420","DOI":"10.1038\/s41564-018-0339-8","article-title":"Phosphatidic acid governs natural egress in Toxoplasma gondii via a guanylate cyclase receptor platform","volume":"4","author":"H Bisio","year":"2019","journal-title":"Nat Microbiol"},{"issue":"21","key":"ppat.1010139.ref006","doi-asserted-by":"crossref","first-page":"3250","DOI":"10.15252\/embj.201796794","article-title":"Crosstalk between PKA and PKG controls pH-dependent host cell egress of Toxoplasma gondii","volume":"36","author":"Y Jia","year":"2017","journal-title":"EMBO J"},{"issue":"9","key":"ppat.1010139.ref007","doi-asserted-by":"crossref","first-page":"e2005642","DOI":"10.1371\/journal.pbio.2005642","article-title":"Protein kinase A negatively regulates Ca2+ signalling in Toxoplasma gondii","volume":"16","author":"AD Uboldi","year":"2018","journal-title":"PLoS Biol"},{"issue":"3","key":"ppat.1010139.ref008","doi-asserted-by":"crossref","first-page":"291","DOI":"10.1111\/j.1550-7408.1987.tb03177.x","article-title":"Effects of extracellular potassium on acid release and motility initiation in Toxoplasma gondii","volume":"34","author":"T Endo","year":"1987","journal-title":"J Protozool"},{"issue":"11","key":"ppat.1010139.ref009","doi-asserted-by":"crossref","first-page":"e1004488","DOI":"10.1371\/journal.ppat.1004488","article-title":"Acidification Activates Toxoplasma gondii Motility and Egress by Enhancing Protein Secretion and Cytolytic Activity.","volume":"10","author":"MS Roiko","year":"2014","journal-title":"PLoS Pathog."},{"issue":"7","key":"ppat.1010139.ref010","doi-asserted-by":"crossref","first-page":"1159","DOI":"10.1084\/jem.186.7.1159","article-title":"pH-dependent Perforation of Macrophage Phagosomes by Listeriolysin O from Listeria monocytogenes","volume":"186","author":"KE Beauregard","year":"1997","journal-title":"J Exp Med"},{"issue":"7","key":"ppat.1010139.ref011","doi-asserted-by":"crossref","first-page":"1641","DOI":"10.1128\/iai.55.7.1641-1646.1987","article-title":"Purification, characterization, and toxicity of the sulfhydryl-activated hemolysin listeriolysin O from Listeria monocytogenes","volume":"55","author":"C Geoffroy","year":"1987","journal-title":"Infect Immun"},{"issue":"8","key":"ppat.1010139.ref012","doi-asserted-by":"crossref","first-page":"4578","DOI":"10.1128\/IAI.68.8.4578-4584.2000","article-title":"Macrophage damage by Leishmania amazonensis cytolysin: evidence of pore formation on cell membrane","volume":"68","author":"FS Noronha","year":"2000","journal-title":"Infect Immun"},{"issue":"7","key":"ppat.1010139.ref013","doi-asserted-by":"crossref","first-page":"1277","DOI":"10.1016\/0092-8674(90)90692-8","article-title":"A T. cruzi-secreted protein immunologically related to the complement component C9: Evidence for membrane pore-forming activity at low pH","volume":"61","author":"NW Andrews","year":"1990","journal-title":"Cell"},{"issue":"1\u20132","key":"ppat.1010139.ref014","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1016\/S1570-9639(04)00031-7","article-title":"Effect of pH and ionic strength on the cytolytic toxin Cyt1A: a fluorescence spectroscopy study","volume":"1699","author":"S. Manceva","year":"2004","journal-title":"Biochim Biophys Acta BBA\u2014Proteins Proteomics"},{"issue":"5","key":"ppat.1010139.ref015","doi-asserted-by":"crossref","first-page":"593","DOI":"10.1016\/j.chom.2015.10.006","article-title":"Malaria Sporozoites Traverse Host Cells within Transient Vacuoles","volume":"18","author":"V Risco-Castillo","year":"2015","journal-title":"Cell Host Microbe"},{"issue":"6689","key":"ppat.1010139.ref016","doi-asserted-by":"crossref","first-page":"192","DOI":"10.1038\/28190","article-title":"Visualizing secretion and synaptic transmission with pH-sensitive green fluorescent proteins","volume":"394","author":"G Miesenbock","year":"1998","journal-title":"Nature"},{"issue":"24","key":"ppat.1010139.ref017","doi-asserted-by":"crossref","first-page":"4524","DOI":"10.1038\/emboj.2012.299","article-title":"Distinct signalling pathways control Toxoplasma egress and host-cell invasion","volume":"31","author":"S Lourido","year":"2012","journal-title":"EMBO J"},{"issue":"44","key":"ppat.1010139.ref018","doi-asserted-by":"crossref","first-page":"41492","DOI":"10.1074\/jbc.M106154200","article-title":"The loss of cytoplasmic potassium upon host cell breakdown triggers egress of Toxoplasma gondii","volume":"276","author":"R Moudy","year":"2001","journal-title":"J Biol Chem"},{"issue":"5913","key":"ppat.1010139.ref019","doi-asserted-by":"crossref","first-page":"530","DOI":"10.1126\/science.1165740","article-title":"Rapid membrane disruption by a perforin-like protein facilitates parasite exit from host cells","volume":"323","author":"BF Kafsack","year":"2009","journal-title":"Science"},{"issue":"2","key":"ppat.1010139.ref020","doi-asserted-by":"crossref","first-page":"509","DOI":"10.1073\/pnas.91.2.509","article-title":"The parasitophorous vacuole membrane surrounding intracellular Toxoplasma gondii functions as a molecular sieve","volume":"91","author":"JC Schwab","year":"1994","journal-title":"Proc Natl Acad Sci U S A"},{"issue":"5","key":"ppat.1010139.ref021","doi-asserted-by":"crossref","first-page":"642","DOI":"10.1016\/j.chom.2015.04.003","article-title":"The Toxoplasma Dense Granule Proteins GRA17 and GRA23 Mediate the Movement of Small Molecules between the Host and the Parasitophorous Vacuole.","volume":"17","author":"DA Gold","year":"2015","journal-title":"Cell Host Microbe."},{"issue":"7","key":"ppat.1010139.ref022","doi-asserted-by":"crossref","first-page":"2132","DOI":"10.1016\/j.celrep.2019.04.038","article-title":"The Toxoplasma Vacuolar H+-ATPase Regulates Intracellular pH and Impacts the Maturation of Essential Secretory Proteins","volume":"27","author":"AJ Stasic","year":"2019","journal-title":"Cell Rep"},{"issue":"5","key":"ppat.1010139.ref023","doi-asserted-by":"crossref","first-page":"653","DOI":"10.1083\/jcb.200309097","article-title":"Ionophore-resistant mutant of Toxoplasma gondii reveals involvement of a sodium\/hydrogen exchanger in calcium regulation","volume":"165","author":"G Arrizabalaga","year":"2004","journal-title":"J Cell Biol"},{"issue":"3","key":"ppat.1010139.ref024","doi-asserted-by":"crossref","first-page":"285","DOI":"10.1016\/j.ijpara.2004.11.015","article-title":"Identification and disruption of a rhoptry-localized homologue of sodium hydrogen exchangers in Toxoplasma gondii","volume":"35","author":"AO Karasov","year":"2005","journal-title":"Int J Parasitol"},{"issue":"10","key":"ppat.1010139.ref025","doi-asserted-by":"crossref","first-page":"1382","DOI":"10.1016\/j.yexcr.2011.03.020","article-title":"A Toxoplasma gondii protein with homology to intracellular type Na+\/H+ Exchangers is important for osmoregulation and invasion","volume":"317","author":"ME Francia","year":"2011","journal-title":"Exp Cell Res"},{"issue":"1A","key":"ppat.1010139.ref026","doi-asserted-by":"crossref","DOI":"10.1099\/acmi.ac2019.po0252","article-title":"Global mapping of protein subcellular location in apicomplexans: the parasite as we\u2019ve never seen it before.","volume":"1","author":"K Barylyuk","year":"2019","journal-title":"Access Microbiol"},{"issue":"3","key":"ppat.1010139.ref027","doi-asserted-by":"crossref","DOI":"10.1128\/mBio.00375-17","article-title":"Plasma Membrane Association by N-Acylation Governs PKG Function in Toxoplasma gondii.","volume":"8","author":"KM Brown","year":"2017","journal-title":"mBio"},{"key":"ppat.1010139.ref028","doi-asserted-by":"crossref","first-page":"6721","DOI":"10.1038\/ncomms7721","article-title":"A lactate and formate transporter in the intraerythrocytic malaria parasite, Plasmodium falciparum.","volume":"6","author":"RV Marchetti","year":"2015","journal-title":"Nat Commun."},{"key":"ppat.1010139.ref029","doi-asserted-by":"crossref","first-page":"6284","DOI":"10.1038\/ncomms7284","article-title":"Identity of a Plasmodium lactate\/H(+) symporter structurally unrelated to human transporters.","volume":"6","author":"B Wu","year":"2015","journal-title":"Nat Commun."},{"issue":"45","key":"ppat.1010139.ref030","doi-asserted-by":"crossref","first-page":"17622","DOI":"10.1074\/jbc.RA118.003801","article-title":"The intracellular parasite Toxoplasma gondii harbors three druggable FNT-type formate and l-lactate transporters in the plasma membrane","volume":"293","author":"H Erler","year":"2018","journal-title":"J Biol Chem"},{"issue":"1","key":"ppat.1010139.ref031","doi-asserted-by":"crossref","first-page":"67","DOI":"10.1186\/s12915-020-00791-7","article-title":"Multi-omics analysis delineates the distinct functions of sub-cellular acetyl-CoA pools in Toxoplasma gondii.","volume":"18","author":"J Kloehn","year":"2020","journal-title":"BMC Biol."},{"issue":"1","key":"ppat.1010139.ref032","doi-asserted-by":"crossref","first-page":"6787","DOI":"10.1038\/s41598-021-86204-3","article-title":"Identifying the major lactate transporter of Toxoplasma gondii tachyzoites.","volume":"11","author":"JM Zeng","year":"2021","journal-title":"Sci Rep."},{"issue":"3","key":"ppat.1010139.ref033","doi-asserted-by":"crossref","first-page":"e0173745","DOI":"10.1371\/journal.pone.0173745","article-title":"Lactate dehydrogenase in Toxoplasma gondii controls virulence, bradyzoite differentiation, and chronic infection.","volume":"12","author":"AE Abdelbaset","year":"2017","journal-title":"PLOS ONE."},{"issue":"1","key":"ppat.1010139.ref034","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/S0378-1119(96)00566-5","article-title":"Toxoplasma gondii expresses two distinct lactate dehydrogenase homologous genes during its life cycle in intermediate hosts","volume":"184","author":"S Yang","year":"1997","journal-title":"Gene"},{"issue":"10","key":"ppat.1010139.ref035","doi-asserted-by":"crossref","first-page":"e1000188","DOI":"10.1371\/journal.ppat.1000188","article-title":"Host Cell Egress and Invasion Induce Marked Relocations of Glycolytic Enzymes in Toxoplasma gondii Tachyzoites.","volume":"4","author":"S Pomel","year":"2008","journal-title":"PLoS Pathog."},{"issue":"1","key":"ppat.1010139.ref036","article-title":"Functional analysis of Toxoplasma lactate dehydrogenases suggests critical roles of lactate fermentation for parasite growth in vivo","volume":"20","author":"N Xia","year":"2018","journal-title":"Cell Microbiol"},{"key":"ppat.1010139.ref037","doi-asserted-by":"crossref","first-page":"1814","DOI":"10.3389\/fimmu.2018.01814","article-title":"A Lactate Fermentation Mutant of Toxoplasma Stimulates Protective Immunity Against Acute and Chronic Toxoplasmosis.","volume":"9","author":"N Xia","year":"2018","journal-title":"Front Immunol"},{"issue":"1","key":"ppat.1010139.ref038","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1128\/EC.00301-07","article-title":"Exit from host cells by the pathogenic parasite Toxoplasma gondii does not require motility","volume":"7","author":"MD Lavine","year":"2008","journal-title":"Eukaryot Cell"},{"issue":"9","key":"ppat.1010139.ref039","doi-asserted-by":"crossref","first-page":"341","DOI":"10.1002\/yea.2967","article-title":"An expanded tool kit for the auxin-inducible degron system in budding yeast","volume":"30","author":"M Morawska","year":"2013","journal-title":"Yeast"},{"issue":"1","key":"ppat.1010139.ref040","doi-asserted-by":"crossref","first-page":"210","DOI":"10.1016\/j.celrep.2016.03.001","article-title":"Rapid Protein Depletion in Human Cells by Auxin-Inducible Degron Tagging with Short Homology Donors","volume":"15","author":"T Natsume","year":"2016","journal-title":"Cell Rep"},{"issue":"3\u20134","key":"ppat.1010139.ref041","doi-asserted-by":"crossref","first-page":"253","DOI":"10.1007\/s10577-017-9559-7","article-title":"An efficient method to generate conditional knockout cell lines for essential genes by combination of auxin-inducible degron tag and CRISPR\/Cas9","volume":"25","author":"K Nishimura","year":"2017","journal-title":"Chromosome Res"},{"issue":"6","key":"ppat.1010139.ref042","doi-asserted-by":"crossref","first-page":"1317","DOI":"10.3390\/cells10061317","article-title":"Mitochondrial Ca2+ Signaling in Health, Disease and Therapy.","volume":"10","author":"L Modesti","year":"2021","journal-title":"Cells"},{"issue":"50","key":"ppat.1010139.ref043","doi-asserted-by":"crossref","first-page":"36129","DOI":"10.1074\/jbc.M113.507285","article-title":"Inhibition of Mitochondrial Pyruvate Transport by Zaprinast Causes Massive Accumulation of Aspartate at the Expense of Glutamate in the Retina","volume":"288","author":"J Du","year":"2013","journal-title":"J Biol Chem"},{"issue":"6","key":"ppat.1010139.ref044","doi-asserted-by":"crossref","first-page":"1358","DOI":"10.1111\/j.1365-2958.2010.07165.x","article-title":"Characterization of a novel organelle in Toxoplasma gondii with similar composition and function to the plant vacuole","volume":"76","author":"K Miranda","year":"2010","journal-title":"Mol Microbiol"},{"key":"ppat.1010139.ref045","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1016\/j.biochi.2021.01.018","article-title":"Aquaporins with lactate\/lactic acid permeability at physiological pH conditions","volume":"188","author":"JDR Schmidt","year":"2021","journal-title":"Biochimie"},{"issue":"16","key":"ppat.1010139.ref046","doi-asserted-by":"crossref","first-page":"9710","DOI":"10.1016\/S0021-9258(17)44555-8","article-title":"Mixed type inhibition of the renal Na+\/H+ antiporter by Li+ and amiloride. Evidence for a modifier site","volume":"258","author":"HE Ives","year":"1983","journal-title":"J Biol Chem"},{"issue":"6","key":"ppat.1010139.ref047","doi-asserted-by":"crossref","first-page":"3503","DOI":"10.1016\/S0021-9258(18)32690-5","article-title":"Biochemical characterization of the amiloride-sensitive Na+\/H+ antiport in Chinese hamster lung fibroblasts","volume":"258","author":"S Paris","year":"1983","journal-title":"J Biol Chem"},{"key":"ppat.1010139.ref048","first-page":"777","volume-title":"Toxoplasma gondii: the model apicomplexan: perspectives and methods","author":"LM Weiss","year":"2007","edition":"1"},{"key":"ppat.1010139.ref049","doi-asserted-by":"crossref","first-page":"11703","DOI":"10.1073\/pnas.90.24.11703","article-title":"Stable molecular transformation of Toxoplasma gondii: A selectable DHFR-TS marker based on drug resistance mutations in malaria","volume":"90","author":"RGK Donald","year":"1993","journal-title":"Proc Natl Acad Sci USA"},{"issue":"4","key":"ppat.1010139.ref050","doi-asserted-by":"crossref","DOI":"10.21769\/BioProtoc.2728","article-title":"Conditional Knockdown of Proteins Using Auxin-inducible Degron (AID) Fusions in Toxoplasma gondii.","volume":"8","author":"KM Brown","year":"2018","journal-title":"Bio-Protoc."},{"issue":"9","key":"ppat.1010139.ref051","doi-asserted-by":"crossref","first-page":"1119","DOI":"10.1017\/S003118201800001X","article-title":"New and emerging uses of CRISPR\/Cas9 to genetically manipulate apicomplexan parasites","volume":"145","author":"M Di Cristina","year":"2018","journal-title":"Parasitology"},{"issue":"1","key":"ppat.1010139.ref052","doi-asserted-by":"crossref","first-page":"401","DOI":"10.1038\/s41467-019-08318-7","article-title":"Alveolar proteins stabilize cortical microtubules in Toxoplasma gondii","volume":"10","author":"CR Harding","year":"2019","journal-title":"Nat Commun"},{"issue":"5","key":"ppat.1010139.ref053","doi-asserted-by":"crossref","first-page":"e1006379","DOI":"10.1371\/journal.ppat.1006379","article-title":"Calmodulin-like proteins localized to the conoid regulate motility and cell invasion by Toxoplasma gondii","volume":"13","author":"S Long","year":"2017","journal-title":"PLoS Pathog"}],"updated-by":[{"DOI":"10.1371\/journal.ppat.1010139","type":"new_version","label":"New version","source":"publisher","updated":{"date-parts":[[2022,5,17]],"date-time":"2022-05-17T00:00:00Z","timestamp":1652745600000}}],"container-title":["PLOS Pathogens"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.ppat.1010139","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,5,17]],"date-time":"2022-05-17T13:59:16Z","timestamp":1652795956000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.ppat.1010139"}},"subtitle":[],"editor":[{"given":"Maria Belen","family":"Cassera","sequence":"first","affiliation":[],"role":[{"role":"editor","vocabulary":"crossref"}]}],"short-title":[],"issued":{"date-parts":[[2022,5,5]]},"references-count":53,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2022,5,5]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.ppat.1010139","relation":{"has-preprint":[{"id-type":"doi","id":"10.1101\/2021.11.25.469974","asserted-by":"object"}]},"ISSN":["1553-7374"],"issn-type":[{"value":"1553-7374","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,5,5]]}}}