{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,27]],"date-time":"2026-08-27T14:43:17Z","timestamp":1787841797855,"version":"build-2784847793"},"reference-count":64,"publisher":"American Society for Microbiology","issue":"6","license":[{"start":{"date-parts":[[2014,11,25]],"date-time":"2014-11-25T00:00:00Z","timestamp":1416873600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-sa\/3.0\/"},{"start":{"date-parts":[[2014,12,31]],"date-time":"2014-12-31T00:00:00Z","timestamp":1419984000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.asm.org\/non-commercial-tdm-license"}],"content-domain":{"domain":["journals.asm.org"],"crossmark-restriction":true},"short-container-title":["mBio"],"published-print":{"date-parts":[[2014,12,31]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n          <jats:p>\n            How the obligatory intracellular bacterium\n            <jats:named-content content-type=\"genus-species\">Ehrlichia chaffeensis<\/jats:named-content>\n            begins to replicate upon entry into human monocytes is poorly understood. Here, we examined the potential role of amino acids in initiating intracellular replication. PutA converts proline to glutamate, and GlnA converts glutamate to glutamine.\n            <jats:italic>E.\u00a0chaffeensis<\/jats:italic>\n            PutA and GlnA complemented\n            <jats:named-content content-type=\"genus-species\">Escherichia coli<\/jats:named-content>\n            <jats:italic>putA<\/jats:italic>\n            and\n            <jats:italic>glnA<\/jats:italic>\n            mutants. Methionine sulfoximine, a glutamine synthetase inhibitor, inhibited\n            <jats:italic>E.\u00a0chaffeensis<\/jats:italic>\n            GlnA activity and\n            <jats:italic>E.\u00a0chaffeensis<\/jats:italic>\n            infection of human cells. Incubation of\n            <jats:italic>E.\u00a0chaffeensis<\/jats:italic>\n            with human cells rapidly induced\n            <jats:italic>putA<\/jats:italic>\n            and\n            <jats:italic>glnA<\/jats:italic>\n            expression that peaked at 24\u00a0h postincubation.\n            <jats:italic>E.\u00a0chaffeensis<\/jats:italic>\n            took up proline and glutamine but not glutamate. Pretreatment of\n            <jats:italic>E.\u00a0chaffeensis<\/jats:italic>\n            with a proline transporter inhibitor (protamine), a glutamine transporter inhibitor (histidine), or proline analogs inhibited\n            <jats:italic>E.\u00a0chaffeensis<\/jats:italic>\n            infection, whereas pretreatment with proline or glutamine enhanced infection and upregulated\n            <jats:italic>putA<\/jats:italic>\n            and\n            <jats:italic>glnA<\/jats:italic>\n            faster than no treatment or glutamate pretreatment. The temporal response of\n            <jats:italic>putA<\/jats:italic>\n            and\n            <jats:italic>glnA<\/jats:italic>\n            expression was similar to that of NtrY and NtrX, a two-component system, and electrophoretic mobility shift assays showed specific binding of recombinant\n            <jats:italic>E.\u00a0chaffeensis<\/jats:italic>\n            NtrX (rNtrX) to the promoter regions of\n            <jats:italic>E.\u00a0chaffeensis putA<\/jats:italic>\n            and\n            <jats:italic>glnA<\/jats:italic>\n            . Furthermore, rNtrX transactivated\n            <jats:italic>E.\u00a0chaffeensis putA<\/jats:italic>\n            and\n            <jats:italic>glnA<\/jats:italic>\n            promoter-\n            <jats:italic>lacZ<\/jats:italic>\n            fusions in\n            <jats:named-content content-type=\"genus-species\">E. coli<\/jats:named-content>\n            . Growth-promoting activities of proline and glutamine were also accompanied by rapid degradation of the DNA-binding protein CtrA. Our results suggest that proline and glutamine uptake regulates\n            <jats:italic>putA<\/jats:italic>\n            and\n            <jats:italic>glnA<\/jats:italic>\n            expression through NtrY\/NtrX and facilitates degradation of CtrA to initiate a new cycle of\n            <jats:italic>E.\u00a0chaffeensis<\/jats:italic>\n            growth.\n          <\/jats:p>\n          <jats:p>\n            <jats:bold>IMPORTANCE<\/jats:bold>\n            Human monocytic ehrlichiosis (HME) is one of the most prevalent, life-threatening emerging infectious zoonoses in the United States. HME is caused by infection with\n            <jats:italic>E.\u00a0chaffeensis<\/jats:italic>\n            , an obligatory intracellular bacterium in the order\n            <jats:italic>Rickettsiales<\/jats:italic>\n            , which includes several category B\/C pathogens, such as those causing Rocky Mountain spotted fever and epidemic typhus. The limited understanding of the mechanisms that control bacterial growth within eukaryotic cells continues to impede the identification of new therapeutic targets against rickettsial diseases. Extracellular rickettsia cannot replicate, but rickettsial replication ensues upon entry into eukaryotic host cells. Our findings will provide insights into a novel mechanism of the two-component system that regulates\n            <jats:italic>E.\u00a0chaffeensis<\/jats:italic>\n            growth initiation in human monocytes. The result is also important because little is known about the NtrY\/NtrX two-component system in any bacteria, let alone obligatory intracellular bacteria. Our findings will advance the field\u2019s current conceptual paradigm on regulation of obligatory intracellular nutrition, metabolism, and growth.\n          <\/jats:p>","DOI":"10.1128\/mbio.02141-14","type":"journal-article","created":{"date-parts":[[2014,11,26]],"date-time":"2014-11-26T05:18:09Z","timestamp":1416979089000},"update-policy":"https:\/\/doi.org\/10.1128\/asmj-crossmark-policy-page","source":"Crossref","is-referenced-by-count":38,"title":["Ehrlichia chaffeensis Proliferation Begins with NtrY\/NtrX and PutA\/GlnA Upregulation and CtrA Degradation Induced by Proline and Glutamine Uptake"],"prefix":"10.1128","volume":"5","author":[{"given":"Zhihui","family":"Cheng","sequence":"first","affiliation":[{"name":"Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mingqun","family":"Lin","sequence":"additional","affiliation":[{"name":"Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yasuko","family":"Rikihisa","sequence":"additional","affiliation":[{"name":"Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"235","reference":[{"key":"e_1_3_3_2_2","first-page":"1","article-title":"Summary of notifiable diseases\u2014United States, 2012","volume":"61","author":"Adams DA","year":"2014","unstructured":"AdamsDA JajoskyRA AjaniU KrisemanJ SharpP OnwenDH SchleyAW AndersonWJ GrigoryanA AranasAE WodajoMS AbelleraJP Centers for Disease Control and Prevention . 2014. Summary of notifiable diseases\u2014United States, 2012. MMWR Morb. Mortal. Wkly. Rep. 61:1\u2013121.","journal-title":"MMWR Morb. Mortal. Wkly. Rep."},{"key":"e_1_3_3_3_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0025-7125(03)00093-2"},{"key":"e_1_3_3_4_2","doi-asserted-by":"publisher","DOI":"10.1128\/CMR.16.1.37-64.2003"},{"key":"e_1_3_3_5_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.tim.2011.04.003"},{"key":"e_1_3_3_6_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pgen.0020021"},{"key":"e_1_3_3_7_2","doi-asserted-by":"publisher","DOI":"10.1146\/annurev.micro.61.080706.093409"},{"key":"e_1_3_3_8_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0021-9258(18)42384-8"},{"key":"e_1_3_3_9_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0021-9258(18)67425-3"},{"key":"e_1_3_3_10_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0021-9258(19)44642-5"},{"key":"e_1_3_3_11_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jmb.2008.05.084"},{"key":"e_1_3_3_12_2","doi-asserted-by":"publisher","DOI":"10.1128\/JB.00744-09"},{"key":"e_1_3_3_13_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1462-5822.2006.00704.x"},{"key":"e_1_3_3_14_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.pep.2007.01.003"},{"key":"e_1_3_3_15_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-2958.2012.08095.x"},{"key":"e_1_3_3_16_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1574-6968.2006.00228.x"},{"key":"e_1_3_3_17_2","doi-asserted-by":"publisher","DOI":"10.1590\/S0100-879X2002000600004"},{"key":"e_1_3_3_18_2","doi-asserted-by":"publisher","DOI":"10.1128\/IAI.00735-06"},{"key":"e_1_3_3_19_2","doi-asserted-by":"publisher","DOI":"10.1152\/jappl.1974.36.6.693"},{"key":"e_1_3_3_20_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-2958.2011.07885.x"},{"key":"e_1_3_3_21_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-2958.2004.04459.x"},{"key":"e_1_3_3_22_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0021-9258(19)68829-0"},{"key":"e_1_3_3_23_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.177.22.6432-6439.1995"},{"key":"e_1_3_3_24_2","doi-asserted-by":"publisher","DOI":"10.1046\/j.1365-2958.1996.01524.x"},{"key":"e_1_3_3_25_2","doi-asserted-by":"publisher","DOI":"10.1128\/JB.182.7.1935-1941.2000"},{"key":"e_1_3_3_26_2","doi-asserted-by":"publisher","DOI":"10.1016\/0022-2836(81)90233-3"},{"key":"e_1_3_3_27_2","doi-asserted-by":"publisher","DOI":"10.1007\/s00726-008-0053-6"},{"key":"e_1_3_3_28_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.146.3.895-901.1981"},{"key":"e_1_3_3_29_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jmb.2006.06.026"},{"key":"e_1_3_3_30_2","doi-asserted-by":"publisher","DOI":"10.1007\/BF02602912"},{"key":"e_1_3_3_31_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0167-4838(99)00270-8"},{"key":"e_1_3_3_32_2","doi-asserted-by":"publisher","DOI":"10.1186\/1745-6150-2-18"},{"key":"e_1_3_3_33_2","doi-asserted-by":"publisher","DOI":"10.1002\/bit.22722"},{"key":"e_1_3_3_34_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi00834a066"},{"key":"e_1_3_3_35_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0021-9258(19)43830-1"},{"key":"e_1_3_3_36_2","doi-asserted-by":"publisher","DOI":"10.1084\/jem.189.9.1425"},{"key":"e_1_3_3_37_2","doi-asserted-by":"publisher","DOI":"10.1099\/13500872-142-12-3389"},{"key":"e_1_3_3_38_2","doi-asserted-by":"publisher","DOI":"10.1007\/s10482-011-9552-7"},{"key":"e_1_3_3_39_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0197-0186(99)00142-4"},{"key":"e_1_3_3_40_2","doi-asserted-by":"publisher","DOI":"10.1007\/BF00293830"},{"key":"e_1_3_3_41_2","doi-asserted-by":"publisher","DOI":"10.3389\/fmicb.2011.00024"},{"key":"e_1_3_3_42_2","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.271.11.6530"},{"key":"e_1_3_3_43_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0092-8674(00)80995-2"},{"key":"e_1_3_3_44_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.tim.2004.06.002"},{"key":"e_1_3_3_45_2","doi-asserted-by":"publisher","DOI":"10.1128\/IAI.70.2.889-898.2002"},{"key":"e_1_3_3_46_2","doi-asserted-by":"publisher","DOI":"10.1128\/IAI.71.7.3927-3936.2003"},{"key":"e_1_3_3_47_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-2958.2005.04899.x"},{"key":"e_1_3_3_48_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.170.11.5012-5017.1988"},{"key":"e_1_3_3_49_2","doi-asserted-by":"publisher","DOI":"10.1128\/iai.61.9.3803-3810.1993"},{"key":"e_1_3_3_50_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.134.3.884-892.1978"},{"key":"e_1_3_3_51_2","first-page":"1991","article-title":"Differential amino acid utilization by Chlamydia psittaci (strain guinea pig inclusion conjunctivitis) and its regulatory effect on chlamydial growth","volume":"129","author":"Allan I","year":"1983","unstructured":"AllanI PearceJH . 1983. Differential amino acid utilization by Chlamydia psittaci (strain guinea pig inclusion conjunctivitis) and its regulatory effect on chlamydial growth. J. Gen. Microbiol. 129:1991\u20132000.","journal-title":"J. Gen. Microbiol."},{"key":"e_1_3_3_52_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1749-6632.2002.tb04366.x"},{"key":"e_1_3_3_53_2","doi-asserted-by":"publisher","DOI":"10.1159\/000103604"},{"key":"e_1_3_3_54_2","first-page":"175","article-title":"Sensory components controlling bacterial nitrogen assimilation","volume":"40","author":"Kamberov ES","year":"1994","unstructured":"KamberovES AtkinsonMR FengJ ChandranP NinfaAJ . 1994. Sensory components controlling bacterial nitrogen assimilation. Cell. Mol. Biol. Res. 40:175\u2013191.","journal-title":"Cell. Mol. Biol. Res."},{"key":"e_1_3_3_55_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.062065699"},{"key":"e_1_3_3_56_2","doi-asserted-by":"publisher","DOI":"10.1038\/nrmicro864"},{"key":"e_1_3_3_57_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.ppat.1003666"},{"key":"e_1_3_3_58_2","doi-asserted-by":"publisher","DOI":"10.1128\/jcm.29.12.2741-2745.1991"},{"key":"e_1_3_3_59_2","doi-asserted-by":"publisher","DOI":"10.1016\/0076-6879(74)32058-7"},{"key":"e_1_3_3_60_2","doi-asserted-by":"publisher","DOI":"10.1016\/0378-1119(89)90358-2"},{"key":"e_1_3_3_61_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.175.11.3679-3684.1993"},{"key":"e_1_3_3_62_2","doi-asserted-by":"publisher","DOI":"10.1128\/JB.01813-07"},{"key":"e_1_3_3_63_2","doi-asserted-by":"publisher","DOI":"10.1128\/iai.62.11.5126-5132.1994"},{"key":"e_1_3_3_64_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.92.19.8866"},{"key":"e_1_3_3_65_2","doi-asserted-by":"publisher","DOI":"10.1128\/JB.00318-07"}],"updated-by":[{"DOI":"10.1128\/mbio.00242-15","type":"correction","label":"Correction","source":"publisher","updated":{"date-parts":[[2015,3,17]],"date-time":"2015-03-17T00:00:00Z","timestamp":1426550400000}}],"container-title":["mBio"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/mBio.02141-14","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/mBio.02141-14","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,3,8]],"date-time":"2022-03-08T01:47:16Z","timestamp":1646704036000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.asm.org\/doi\/10.1128\/mBio.02141-14"}},"subtitle":[],"editor":[{"given":"Michele S.","family":"Swanson","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2014,12,31]]},"references-count":64,"journal-issue":{"issue":"6","published-print":{"date-parts":[[2014,12,31]]}},"alternative-id":["10.1128\/mBio.02141-14"],"URL":"https:\/\/doi.org\/10.1128\/mbio.02141-14","relation":{"correction":[{"id-type":"doi","id":"10.1128\/mBio.00242-15","asserted-by":"object"}]},"ISSN":["2161-2129","2150-7511"],"issn-type":[{"value":"2161-2129","type":"print"},{"value":"2150-7511","type":"electronic"}],"subject":[],"published":{"date-parts":[[2014,12,31]]},"assertion":[{"value":"2014-10-29","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2014-11-04","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2014-11-25","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e02141-14"}}