{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,27]],"date-time":"2026-02-27T05:09:51Z","timestamp":1772168991765,"version":"3.50.1"},"update-to":[{"DOI":"10.12688\/f1000research.2-238.v1","type":"new_version","label":"New version","source":"publisher","updated":{"date-parts":[[2014,5,23]],"date-time":"2014-05-23T00:00:00Z","timestamp":1400803200000}}],"reference-count":37,"publisher":"F1000 Research Ltd","license":[{"start":{"date-parts":[[2014,5,23]],"date-time":"2014-05-23T00:00:00Z","timestamp":1400803200000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":["f1000research.com"],"crossmark-restriction":false},"short-container-title":["F1000Res"],"abstract":"<ns4:p>\n                    <ns4:italic>Candida albicans<\/ns4:italic>\n                    \u00a0is a mucosal commensal organism capable of causing superficial (oral and vaginal thrush) infections in immune normal hosts, but is a major pathogen causing systemic and mucosal infections in immunocompromised individuals. Azoles have been very effective anti-fungal agents and the mainstay in treating opportunistic mold and yeast infections. Azole resistant strains have emerged compromising the utility of this class of drugs. It has been shown that azole resistance can be reversed by the co-administration of a histone deacetylase (HDAC) inhibitor, suggesting that resistance is mediated by epigenetic mechanisms possibly involving Hos2, a fungal deacetylase. We report here the cloning and functional characterization of\u00a0\n                    <ns4:italic>HOS2 (H<\/ns4:italic>\n                    igh\n                    <ns4:italic>O<\/ns4:italic>\n                    smolarity\u00a0\n                    <ns4:italic>S<\/ns4:italic>\n                    ensitive)\n                    <ns4:italic>,<\/ns4:italic>\n                    \u00a0a gene coding for fungal histone deacetylase from\u00a0\n                    <ns4:italic>C. albicans<\/ns4:italic>\n                    . Inhibition studies showed that Hos2 is susceptible to pan inhibitors such as trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA), but is not inhibited by class I inhibitors such as MS-275. This\u00a0\n                    <ns4:italic>in<\/ns4:italic>\n                    \u00a0\n                    <ns4:italic>vitro<\/ns4:italic>\n                    \u00a0enzymatic assay, which is amenable to high throughput could be used for screening potent fungal Hos2 inhibitors that could be a potential anti-fungal adjuvant. Purified Hos2 protein consistently deacetylated tubulins, rather than histones from TSA-treated cells. Hos2 has been reported to be a putative NAD+ dependent histone deacetylase, a feature of sirtuins. We assayed for sirtuin activation with resveratrol and purified Hos2 protein and did not find any sirtuin activity.\n                  <\/ns4:p>","DOI":"10.12688\/f1000research.2-238.v2","type":"journal-article","created":{"date-parts":[[2014,5,23]],"date-time":"2014-05-23T12:47:11Z","timestamp":1400849231000},"page":"238","update-policy":"https:\/\/doi.org\/10.12688\/f1000research.crossmark-policy","source":"Crossref","is-referenced-by-count":1,"title":["Functional characterization of Candida albicans Hos2 histone deacetylase"],"prefix":"10.12688","volume":"2","author":[{"given":"G","family":"Karthikeyan","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Maneesh","family":"Paul-Satyaseela","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nachiappan","family":"Dhatchana Moorthy","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Radha","family":"Gopalaswamy","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shridhar","family":"Narayanan","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"2560","published-online":{"date-parts":[[2014,5,23]]},"reference":[{"key":"ref-1","article-title":"Candida and candidosis: a review and bibliography","author":"F Odds","year":"1988"},{"key":"ref-2","doi-asserted-by":"publisher","first-page":"3254-3259","DOI":"10.1128\/JCM.39.9.3254-3259.2001","article-title":"International surveillance of bloodstream infections due to Candida species: frequency of occurrence and In vitro susceptibilities to fluconazole, ravuconazole, and voriconazole of isolates collected from 1997 through 1999 in the SENTRY antimicrobial surveillance program.","volume":"39","author":"M Pfaller","year":"2001","journal-title":"J Clin Microbiol."},{"key":"ref-3","doi-asserted-by":"publisher","first-page":"981-998","DOI":"10.1586\/eri.09.67","article-title":"New triazoles and echinocandins: mode of action, In vitro activity and mechanisms of resistance.","volume":"7","author":"M Fera","year":"2009","journal-title":"Expert Rev Anti Infect Ther."},{"key":"ref-4","doi-asserted-by":"crossref","first-page":"241-253","DOI":"10.1128\/AAC.42.2.241","article-title":"Amino acid substitutions in the cytochrome P-450 lanosterol 14alpha-demethylase (CYP51A1) from azole-resistant Candida albicans clinical isolates contribute to resistance to azole antifungal agents.","volume":"42","author":"D Sanglard","year":"1998","journal-title":"Antimicrob Agents Chemother."},{"key":"ref-5","doi-asserted-by":"crossref","first-page":"1488-1494","DOI":"10.1128\/AAC.41.7.1488","article-title":"The presence of an R467K amino acid substitution and loss of allelic variation correlate with an azole-resistant lanosterol 14alpha demethylase in Candida albicans.","volume":"41","author":"T White","year":"1997","journal-title":"Antimicrob Agents Chemother."},{"key":"ref-6","doi-asserted-by":"publisher","first-page":"1136-1144","DOI":"10.1128\/AAC.48.4.1136-1144.2004","article-title":"The Candida albicans lanosterol 14-alpha-demethylase (ERG11) gene promoter is maximally induced after prolonged growth with antifungal drugs.","volume":"48","author":"J Song","year":"2004","journal-title":"Antimicrob Agents Chemother."},{"key":"ref-7","doi-asserted-by":"publisher","first-page":"2378-2386","DOI":"10.1128\/AAC.39.11.2378","article-title":"Mechanisms of resistance to azole antifungal agents in Candida albicans isolates from AIDS patients involve specific multidrug transporters.","volume":"39","author":"D Sanglard","year":"1995","journal-title":"Antimicrob Agents Chemother."},{"key":"ref-8","doi-asserted-by":"crossref","first-page":"2835-2841","DOI":"10.1128\/AAC.40.12.2835","article-title":"Multiple efflux mechanisms are involved in Candida albicans fluconazole resistance.","volume":"40","author":"G Albertson","year":"1996","journal-title":"Antimicrob Agents Chemother."},{"key":"ref-9","doi-asserted-by":"crossref","first-page":"2584-2589","DOI":"10.1128\/AAC.42.10.2584","article-title":"Rapid, transient fluconazole resistance in Candida albicans is associated with increased mRNA levels of CDR.","volume":"42","author":"K Marr","year":"1998","journal-title":"Antimicrob Agents Chemother."},{"key":"ref-10","doi-asserted-by":"publisher","first-page":"289-296","DOI":"10.1016\/j.molcel.2006.06.017","article-title":"Enhanced histone acetylation and transcription: a dynamic perspective.","volume":"23","author":"A Clayton","year":"2006","journal-title":"Mol Cell."},{"key":"ref-11","doi-asserted-by":"publisher","first-page":"1351-1356","DOI":"10.1038\/sj.onc.1210204","article-title":"Discovery and development of SAHA as an anticancer agent.","volume":"26","author":"P Marks","year":"2007","journal-title":"Oncogene."},{"key":"ref-12","doi-asserted-by":"publisher","first-page":"787-795","DOI":"10.1358\/dot.2009.45.11.1437052","article-title":"Romidepsin for the treatment of cutaneous T-cell lymphoma.","volume":"45","author":"C Campas-Moya","year":"2009","journal-title":"Drugs Today (Barc.)."},{"key":"ref-13","first-page":"377-392","article-title":"Update on the treatment of cutaneous T-cell lymphoma (CTCL): Focus on vorinostat.","volume":"1","author":"M Duvic","year":"2007","journal-title":"Biologics."},{"key":"ref-14","doi-asserted-by":"publisher","first-page":"981-989","DOI":"10.1158\/1541-7786.MCR-07-0324","article-title":"Histone deacetylase inhibitors: overview and perspectives.","volume":"5","author":"M Dokmanovic","year":"2007","journal-title":"Mol Cancer Res."},{"key":"ref-15","doi-asserted-by":"publisher","first-page":"835-851","DOI":"10.1517\/14728222.11.6.835","article-title":"The therapeutic uses of chromatin-modifying agents.","volume":"11","author":"A Mai","year":"2007","journal-title":"Expert Opin Ther Targets."},{"key":"ref-16","doi-asserted-by":"publisher","first-page":"499-514","DOI":"10.1007\/s00253-007-0912-1","article-title":"Histone deacetylase inhibitors--turning epigenic mechanisms of gene regulation into tools of therapeutic intervention in malignant and other diseases.","volume":"75","author":"D Riester","year":"2007","journal-title":"Appl Microbiol Biotechnol."},{"key":"ref-17","doi-asserted-by":"publisher","first-page":"3532-3539","DOI":"10.1128\/AAC.46.11.3532-3539.2002","article-title":"Histone deacetylase inhibitors enhance Candida albicans sensitivity to azoles and related antifungals: correlation with reduction in CDR and ERG upregulation.","volume":"46","author":"W Smith","year":"2002","journal-title":"Antimicrob Agents Chemother."},{"key":"ref-18","doi-asserted-by":"publisher","first-page":"3797-3804","DOI":"10.1128\/JCM.00618-09","article-title":"Activity of MGCD290, a Hos2 histone deacetylase inhibitor, in combination with azole antifungals against opportunistic fungal pathogens.","volume":"47","author":"M Pfaller","year":"2009","journal-title":"J Clin Microbiol."},{"key":"ref-19","doi-asserted-by":"publisher","first-page":"1371-1380","DOI":"10.1111\/j.1567-1364.2007.00276.x","article-title":"Histone deacetylase inhibitors may reduce pathogenicity and virulence in Candida albicans.","volume":"7","author":"G Simonetti","year":"2007","journal-title":"FEMS Yeast Res."},{"key":"ref-20","doi-asserted-by":"publisher","first-page":"1412-1414","DOI":"10.1126\/science.1077790","article-title":"Requirement of Hos2 histone deacetylase for gene activity in yeast.","volume":"298","author":"A Wang","year":"2002","journal-title":"Science."},{"key":"ref-21","doi-asserted-by":"publisher","first-page":"1-15","DOI":"10.1111\/j.1365-2958.2009.06772.x","article-title":"Transcriptional loops meet chromatin: a dual-layer network controls white-opaque switching in Candida albicans.","volume":"74","author":"D Hnisz","year":"2009","journal-title":"Mol Microbiol."},{"key":"ref-22","doi-asserted-by":"publisher","first-page":"e1000889","DOI":"10.1371\/journal.ppat.1000889","article-title":"The Set3\/Hos2 histone deacetylase complex attenuates cAMP\/PKA signaling to regulate morphogenesis and virulence of Candida albicans.","volume":"6","author":"D Hnisz","year":"2010","journal-title":"PLoS Pathog."},{"key":"ref-23","article-title":"Candida Genome Database","author":"I Arnaud MB"},{"key":"ref-24","doi-asserted-by":"publisher","first-page":"774-780","DOI":"10.1038\/nm.2175","article-title":"Modulation of histone H3 lysine 56 acetylation as an antifungal therapeutic strategy.","volume":"16","author":"H Wurtele","year":"2010","journal-title":"Nat Med."},{"key":"ref-25","doi-asserted-by":"publisher","first-page":"e49761","DOI":"10.1371\/journal.pone.0049761","article-title":"A molecular mechanism for direct sirtuin activation by resveratrol.","volume":"7","author":"M Gertz","year":"2012","journal-title":"PLoS One."},{"key":"ref-26","doi-asserted-by":"publisher","DOI":"10.1002\/0471142727.mb1104s18","article-title":"Immunization of Mice.","author":"S Fuller","year":"2001","journal-title":"Curr Protoc Mol Biol."},{"key":"ref-27","doi-asserted-by":"publisher","first-page":"1445-1457","DOI":"10.1038\/nprot.2007.202","article-title":"Extraction, purification and analysis of histones.","volume":"2","author":"D Shechter","year":"2007","journal-title":"Nat Protoc."},{"key":"ref-28","article-title":"Yeast Nuclei Isolation"},{"key":"ref-29","doi-asserted-by":"publisher","first-page":"312-319","DOI":"10.1016\/j.ymeth.2006.08.017","article-title":"Quantitative profiling of histone post-translational modifications by stable isotope labeling.","volume":"41","author":"A Knapp","year":"2007","journal-title":"Methods."},{"key":"ref-30","doi-asserted-by":"publisher","first-page":"2906-2918","DOI":"10.1038\/sj.emboj.7600758","article-title":"Genomewide analysis of nucleosome density histone acetylation and HDAC function in fission yeast.","volume":"24","author":"M Wiren","year":"2005","journal-title":"EMBO J."},{"key":"ref-31","doi-asserted-by":"publisher","first-page":"e1003118","DOI":"10.1371\/journal.pgen.1003118","article-title":"A histone deacetylase adjusts transcription kinetics at coding sequences during Candida albicans morphogenesis.","volume":"8","author":"D Hnisz","year":"2012","journal-title":"PLoS Genet."},{"key":"ref-32","doi-asserted-by":"publisher","first-page":"e12171","DOI":"10.1371\/journal.pone.0012171","article-title":"HOS2 and HDA1 encode histone deacetylases with opposing roles in Candida albicans morphogenesis.","volume":"5","author":"L Zacchi","year":"2010","journal-title":"PLoS One."},{"key":"ref-33","doi-asserted-by":"publisher","first-page":"437-446","DOI":"10.1016\/S0092-8674(02)00746-8","article-title":"Microarray deacetylation maps determine genome-wide functions for yeast histone deacetylases.","volume":"109","author":"D Robyr","year":"2002","journal-title":"Cell."},{"key":"ref-34","doi-asserted-by":"publisher","first-page":"1697-1711","DOI":"10.1128\/EC.4.10.1697-1711.2005","article-title":"Microtubules in Candida albicans Hyphae Drive Nuclear Dynamics and Connect Cell Cycle Progression to Morphogenesis.","volume":"4","author":"K Finley","year":"2005","journal-title":"Eukaryot Cell."},{"key":"ref-35","doi-asserted-by":"publisher","DOI":"10.6084\/m9.figshare.841666","article-title":"Tubulin deacetylation and rHos2 protein blots.","author":"G Karthikeyan","year":"2014","journal-title":"figshare."},{"key":"ref-36","doi-asserted-by":"publisher","DOI":"10.6084\/m9.figshare.841655","article-title":"Deacetylase activities of rHos2 and dose response curves of rHos2 inhibition by standard HDAC inhibitors.","author":"G Karthikeyan","year":"2014","journal-title":"figshare."},{"key":"ref-37","doi-asserted-by":"publisher","DOI":"10.6084\/m9.figshare.841658","article-title":"Sirtuin assay of purified Hos2 preparations using resveratrol.","author":"G Karthikeyan","year":"2014","journal-title":"figshare."}],"updated-by":[{"DOI":"10.12688\/f1000research.2-238.v3","type":"new_version","label":"New version","source":"publisher","updated":{"date-parts":[[2014,7,22]],"date-time":"2014-07-22T00:00:00Z","timestamp":1405987200000}}],"container-title":["F1000Research"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/f1000research.com\/articles\/2-238\/v2\/xml","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/f1000research.com\/articles\/2-238\/v2\/pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/f1000research.com\/articles\/2-238\/v2\/iparadigms","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2020,8,19]],"date-time":"2020-08-19T21:30:01Z","timestamp":1597872601000},"score":1,"resource":{"primary":{"URL":"https:\/\/f1000research.com\/articles\/2-238\/v2"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2014,5,23]]},"references-count":37,"aliases":["10.12688\/f1000research.2-238.v3"],"URL":"https:\/\/doi.org\/10.12688\/f1000research.2-238.v2","relation":{"has-review":[{"id-type":"doi","id":"10.5256\/f1000research.4538.r5126","asserted-by":"subject"},{"id-type":"doi","id":"10.5256\/f1000research.4538.r4908","asserted-by":"subject"},{"id-type":"doi","id":"10.5256\/f1000research.4538.r5126","asserted-by":"object"},{"id-type":"doi","id":"10.5256\/f1000research.4538.r4908","asserted-by":"object"}]},"ISSN":["2046-1402"],"issn-type":[{"value":"2046-1402","type":"electronic"}],"subject":[],"published":{"date-parts":[[2014,5,23]]},"assertion":[{"value":"Indexed","URL":"https:\/\/f1000research.com\/articles\/2-238\/v2#article-reports","order":0,"name":"referee-status","label":"Referee status","group":{"name":"current-referee-status","label":"Current Referee Status"}},{"value":"10.5256\/f1000research.4538.r4908, Donna MacCallum, Aberdeen Fungal Group, University of Aberdeen, Aberdeen, UK, 11 Jun 2014, version 2, indexed","URL":"https:\/\/f1000research.com\/articles\/2-238\/v2#referee-response-4908","order":0,"name":"referee-response-4908","label":"Referee Report","group":{"name":"article-reports","label":"Article Reports"}},{"value":"10.5256\/f1000research.2168.r4017, David Soll, Department of Biology, University of Iowa, Iowa City, IA, USA, 16 Apr 2014, version 1, 2 approved with reservations","URL":"https:\/\/f1000research.com\/articles\/2-238\/v1#referee-response-4017","order":1,"name":"referee-response-4017","label":"Referee Report","group":{"name":"article-reports","label":"Article Reports"}},{"value":"<b>Karthikeyan Ganesan<\/b>; <i>Posted: 13 May 2014<\/i>; As a pharmaceutical organization, involved in drug discovery, our initial compound libraries are screened for <i> in vitro<\/i> activity\/inhibition assays. These <i>in vitro<\/i> assays act as important filters removing in-active compounds to progress only the most potent ones to <i>in vivo<\/i> screening.Deacetylase assays using recombinant Hos2 enzyme and synthetic substrate Boc (Lys) AMC showed that the enzyme is active in standard fluorogenic assays.&nbsp; Absence of deacetylase activity with histone preparations&nbsp;(Human\/ <i>Candida<\/i>) in the <i>in vitro<\/i> histone deacetylation assays was a surprise but the fact that Class I HDAC inhibitor like MS-275 did not inhibit rHos2 in standard fluorogenic assays, led us to explore alternate substrate, namely tubulins.We do agree with the reviewer that anti-tubulin deacetylase activity could be an artifact of recombinant protein, but we strongly feel that it is a remote possibility.Any small molecule that shows anti-tubulin or anti-HDAC6 activity would be picked up in the <i>in vitro<\/i> screen and would be prevented from moving further up the discovery path. (Which can be re-purposed for different therapeutic )We are indeed aware of the previous studies showing the effect of Set3\/Hos2 complex and the opposing roles of Hda1 and Hos2 in <i>Candida <\/i>morphogenesis as well as the role of Hos2 in S. cerevisiae. In these studies Histone H4 acetylation levels vary dramatically, especially H4-K16, however the Histone H3 levels more or less remain constant, (supplementary materials from Wang <i>et al.<\/i>, 2002) and that`s probably the reason why we don`t see any dramatic deacetylation when probed with Histone H3-K9. The study by Pfaller <i>et al.<\/i> did have <i>in vivo<\/i> data, but did not have any <i>in vitro<\/i> data.Error bars and statistical analysis have been incorporated for Figs. 1 and 5. Units for Fig. 2 and Table 2 corrected.Label has been changed for Fig. 4Fold activity and Fold activation is with respect to Blank and has been reflected in the figures.","URL":"https:\/\/f1000research.com\/articles\/2-238\/v2#referee-comment-819","order":2,"name":"referee-comment-819","label":"Referee Comment","group":{"name":"article-reports","label":"Article Reports"}},{"value":"10.5256\/f1000research.4538.r5126, Malcolm S. Whiteway, Department of Biology, Concordia University, Montr\u00e9al, QC, Canada, 26 Jun 2014, version 2, indexed","URL":"https:\/\/f1000research.com\/articles\/2-238\/v2#referee-response-5126","order":3,"name":"referee-response-5126","label":"Referee Report","group":{"name":"article-reports","label":"Article Reports"}},{"value":"<b>Karthikeyan Ganesan<\/b>; <i>Posted: 07 Jul 2014<\/i>; The points raised by the referee are addressed in the new version of the article.We have carried out a separate experiment to show that the signal in the western blot is specific (this can be downloaded here&nbsp;but is&nbsp;not included in the revised article).Fig 1B was specifically modified at the request of the editorial team during the initial stage and subsequently modified based on inputs from other referee(s).The title has now been modified to reflect that tubulins are deacetylated and not histones.We used HeLa nuclear extracts as positive control for Sirtuin assay and Resveratrol did show Sirtuin activation.Minor Comment regarding the mention of 1st and 271st CUG codon will be modified&nbsp;in the revised article.","URL":"https:\/\/f1000research.com\/articles\/2-238\/v2#referee-comment-892","order":4,"name":"referee-comment-892","label":"Referee Comment","group":{"name":"article-reports","label":"Article Reports"}},{"value":"This was an exploratory in-house project funded solely by Orchid Chemicals and Pharmaceuticals Limited. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.","order":5,"name":"grant-information","label":"Grant Information"},{"value":"This is an open access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Data associated with the article are available under the terms of the Creative Commons Zero \"No rights reserved\" data waiver (CC0 1.0 Public domain dedication).","order":0,"name":"copyright-info","label":"Copyright"}]}}