{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"bioRxiv"}],"indexed":{"date-parts":[[2026,2,6]],"date-time":"2026-02-06T10:20:34Z","timestamp":1770373234741,"version":"3.49.0"},"posted":{"date-parts":[[2026,1,29]]},"group-title":"Microbiology","reference-count":39,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2026,1,29]],"date-time":"2026-01-29T00:00:00Z","timestamp":1769644800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2026,1,29]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                <jats:p>\n                  <jats:italic>Mycobacterium abscessus<\/jats:italic>\n                  is an emerging threat, causing infections that are difficult to treat due to intrinsic resistance to most antibiotics. Determinants of\n                  <jats:italic>M. abscessus<\/jats:italic>\n                  physiology and pathogenesis remain poorly understood, hampering therapeutic development. Here, we show that in\n                  <jats:italic>M. abscessus<\/jats:italic>\n                  , the\n                  <jats:italic>lprg-mfs<\/jats:italic>\n                  operon is essential for virulence in macrophages and in mice. Loss of\n                  <jats:italic>lprg-mfs<\/jats:italic>\n                  in\n                  <jats:italic>M. abscessus<\/jats:italic>\n                  causes accumulation of the glycolipid lipoarabinomannan (LAM) on the cell surface and in culture supernatant suggesting that this system participates in LAM import. This contrasts with its proposed role in\n                  <jats:italic>M. tuberculosis<\/jats:italic>\n                  where\n                  <jats:italic>lprg-mfs<\/jats:italic>\n                  has been implicated in the export of various lipids. Consistent with altered lipid distribution, the\n                  <jats:italic>lprg-mfs<\/jats:italic>\n                  mutant displays severe defects in mycomembrane permeability, fluidity, and integrity, and expression of\n                  <jats:italic>mfs<\/jats:italic>\n                  alone restores only a subset of these phenotypes, revealing a surprising uncoupling of envelope fluidity and permeability. Using a suppressor screen to further investigate factors that control the distribution of lipoarabinomannan we find that a point mutation in the unannotated gene\n                  <jats:italic>MAB_0995<\/jats:italic>\n                  can fully or partially complement all deletion mutant phenotypes. Our data also show that lipoarabinomannan in the mycomembrane is dynamically regulated in response to environmental conditions, including hypoxia and macrophage infection. Together, these findings redefine the role of LprG\/Mfs in mycobacterial cell envelope homeostasis and reveal unexpected plasticity in mycomembrane lipid regulation in\n                  <jats:italic>M. abscessus<\/jats:italic>\n                  .\n                <\/jats:p>\n                <jats:sec>\n                  <jats:title>Importance<\/jats:title>\n                  <jats:p>\n                    The emerging pathogen\n                    <jats:italic>Mycobacterium abscessus<\/jats:italic>\n                    causes life-threatening lung infections in certain patients that are extremely difficult to treat due to its intrinsic resistance to most antibiotics. However, the process by which this organism establishes infection is poorly understood, as are the specific determinants of antibiotic tolerance. Better knowledge of the genes required for virulence and impermeability to antibiotics in\n                    <jats:italic>M. abscessus<\/jats:italic>\n                    could enable to development of more effective treatments. The significance of this study is the demonstration that the\n                    <jats:italic>lprg-mfs<\/jats:italic>\n                    operon is required both for pathogenesis and for impermeability in\n                    <jats:italic>M. abscessus<\/jats:italic>\n                    . Further, our study shows a correlation between cell envelope characteristics and the distribution of the molecule lipoarabinomannan, suggesting a specific mechanism by which these crucial characteristics are mediated.\n                  <\/jats:p>\n                <\/jats:sec>","DOI":"10.64898\/2026.01.29.702501","type":"posted-content","created":{"date-parts":[[2026,1,30]],"date-time":"2026-01-30T03:10:13Z","timestamp":1769742613000},"source":"Crossref","is-referenced-by-count":0,"title":["A highly conserved two-gene operon is crucial for lipoarabinomannan localization, pathogenesis, and cell envelope function in\n                  <i>Mycobacterium abscessus<\/i>"],"prefix":"10.64898","author":[{"given":"Nicholas","family":"Campbell-Kruger","sequence":"first","affiliation":[{"name":"Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Amir","family":"Balakhmet","sequence":"additional","affiliation":[{"name":"Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4182-9048","authenticated-orcid":false,"given":"Sarah A.","family":"Stanley","sequence":"additional","affiliation":[{"name":"Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"54368","reference":[{"key":"2026020511124373000_2026.01.29.702501v1.1","unstructured":"World Health Organization. 2025. Global tuberculosis report 2025. World Health Organization, Geneva."},{"key":"2026020511124373000_2026.01.29.702501v1.2","doi-asserted-by":"crossref","unstructured":"Daff\u00e9 M , Marrakchi H. 2019. Unraveling the structure of the mycobacterial envelope. Gram-Positive Pathogens 1087\u20131095.","DOI":"10.1128\/9781683670131.ch65"},{"key":"2026020511124373000_2026.01.29.702501v1.3","doi-asserted-by":"publisher","DOI":"10.1038\/srep41926"},{"key":"2026020511124373000_2026.01.29.702501v1.4","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1403078111"},{"key":"2026020511124373000_2026.01.29.702501v1.5","doi-asserted-by":"publisher","DOI":"10.1016\/j.cmi.2023.08.035"},{"key":"2026020511124373000_2026.01.29.702501v1.6","doi-asserted-by":"crossref","first-page":"e0008023","DOI":"10.1128\/cmr.00080-23","article-title":"Toward better cures for Mycobacterium abscessus lung disease","volume":"37","year":"2024","journal-title":"Clin Microbiol Rev"},{"key":"2026020511124373000_2026.01.29.702501v1.7","doi-asserted-by":"publisher","DOI":"10.1371\/journal.ppat.1011318"},{"key":"2026020511124373000_2026.01.29.702501v1.8","doi-asserted-by":"crossref","unstructured":"Martinot AJ , Farrow M , Bai L , Layre E , Cheng TY , Tsai JH , Iqbal J , Annand JW , Sullivan ZA , Hussain MM , Sacchettini J , Moody DB , Seeliger JC , Rubin EJ . 2016. Mycobacterial Metabolic Syndrome: LprG and Rv1410 Regulate Triacylglyceride Levels, Growth Rate and Virulence in Mycobacterium tuberculosis. PLoS Pathog 12.","DOI":"10.1371\/journal.ppat.1005351"},{"key":"2026020511124373000_2026.01.29.702501v1.9","doi-asserted-by":"publisher","DOI":"10.1016\/j.micinf.2003.10.010"},{"key":"2026020511124373000_2026.01.29.702501v1.10","doi-asserted-by":"publisher","DOI":"10.1038\/nsmb.1869"},{"key":"2026020511124373000_2026.01.29.702501v1.11","doi-asserted-by":"publisher","DOI":"10.1371\/journal.ppat.1004376"},{"key":"2026020511124373000_2026.01.29.702501v1.12","doi-asserted-by":"publisher","DOI":"10.1111\/mmi.14220"},{"key":"2026020511124373000_2026.01.29.702501v1.13","doi-asserted-by":"crossref","unstructured":"Lissner R , Franklin A , Benedict ST , Charitou V , Speer A , Knol J , Jimenez C , Moynihan PJ , Nejentsev S , Kuijl C , Bitter W. 2025. A new role for lipoproteins LpqZ and FecB in orchestrating mycobacterial cell envelope biogenesis. MBio e0211925.","DOI":"10.1101\/2025.06.19.660376"},{"key":"2026020511124373000_2026.01.29.702501v1.14","doi-asserted-by":"publisher","DOI":"10.1128\/mBio.01256-18"},{"key":"2026020511124373000_2026.01.29.702501v1.15","doi-asserted-by":"publisher","DOI":"10.1128\/IAI.00014-07"},{"key":"2026020511124373000_2026.01.29.702501v1.16","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.00459-15"},{"key":"2026020511124373000_2026.01.29.702501v1.17","doi-asserted-by":"publisher","DOI":"10.1093\/jac\/dkt451"},{"key":"2026020511124373000_2026.01.29.702501v1.18","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-022-28638-5"},{"key":"2026020511124373000_2026.01.29.702501v1.19","doi-asserted-by":"crossref","first-page":"910","DOI":"10.1016\/j.chembiol.2022.03.008","article-title":"Glycopeptidolipid glycosylation controls surface properties and pathogenicity in Mycobacterium abscessus","volume":"29","year":"2022","journal-title":"Cell Chemical Biology"},{"key":"2026020511124373000_2026.01.29.702501v1.20","doi-asserted-by":"publisher","DOI":"10.1099\/mic.0.28625-0"},{"key":"2026020511124373000_2026.01.29.702501v1.21","first-page":"6234","article-title":"Lipoarabinomannan of Mycobacterium tuberculosis","volume":"267","year":"1992","journal-title":"Capping with mannosyl residues in some strains. J Biol Chem"},{"key":"2026020511124373000_2026.01.29.702501v1.22","doi-asserted-by":"publisher","DOI":"10.1099\/00221287-148-10-3049"},{"key":"2026020511124373000_2026.01.29.702501v1.23","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.0603049103"},{"key":"2026020511124373000_2026.01.29.702501v1.24","doi-asserted-by":"publisher","DOI":"10.1371\/journal.ppat.1004471"},{"key":"2026020511124373000_2026.01.29.702501v1.25","doi-asserted-by":"publisher","DOI":"10.1016\/j.chom.2015.06.001"},{"key":"2026020511124373000_2026.01.29.702501v1.26","doi-asserted-by":"crossref","first-page":"1144210","DOI":"10.3389\/fcimb.2023.1144210","article-title":"Mycobacterium abscessus DosRS two-component system controls a species-specific regulon required for adaptation to hypoxia","volume":"13","year":"2023","journal-title":"Front Cell Infect Microbiol"},{"key":"2026020511124373000_2026.01.29.702501v1.27","doi-asserted-by":"publisher","DOI":"10.3389\/fmicb.2019.01347"},{"key":"2026020511124373000_2026.01.29.702501v1.28","doi-asserted-by":"publisher","DOI":"10.3390\/cells11030361"},{"key":"2026020511124373000_2026.01.29.702501v1.29","doi-asserted-by":"crossref","first-page":"1168","DOI":"10.1080\/22221751.2019.1649097","article-title":"Mycobacterial mannose-capped lipoarabinomannan: a modulator bridging innate and adaptive immunity","volume":"8","year":"2019","journal-title":"Emerg Microbes Infect"},{"key":"2026020511124373000_2026.01.29.702501v1.30","doi-asserted-by":"publisher","DOI":"10.1016\/j.tube.2015.09.005"},{"key":"2026020511124373000_2026.01.29.702501v1.31","doi-asserted-by":"publisher","DOI":"10.3389\/fmicb.2018.00803"},{"key":"2026020511124373000_2026.01.29.702501v1.32","doi-asserted-by":"publisher","DOI":"10.1016\/j.jlr.2022.100262"},{"key":"2026020511124373000_2026.01.29.702501v1.33","doi-asserted-by":"crossref","first-page":"352","DOI":"10.1021\/acsinfecdis.5b00148","article-title":"Cell-Envelope Remodeling as a Determinant of Phenotypic Antibacterial Tolerance in Mycobacterium tuberculosis","volume":"2","year":"2016","journal-title":"ACS Infect Dis"},{"key":"2026020511124373000_2026.01.29.702501v1.34","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.M200408200"},{"key":"2026020511124373000_2026.01.29.702501v1.35","doi-asserted-by":"crossref","first-page":"1497","DOI":"10.1002\/prot.26170","article-title":"On the diversity of F420-dependent oxidoreductases: A sequence- and structure-based classification","volume":"89","year":"2021","journal-title":"Proteins"},{"key":"2026020511124373000_2026.01.29.702501v1.36","doi-asserted-by":"publisher","DOI":"10.1038\/s41598-018-35590-2"},{"key":"2026020511124373000_2026.01.29.702501v1.37","doi-asserted-by":"crossref","first-page":"481","DOI":"10.1038\/s41564-022-01307-5","article-title":"Biotin-dependent cell envelope remodelling is required for Mycobacterium abscessus survival in lung infection","volume":"8","year":"2023","journal-title":"Nat Microbiol"},{"key":"2026020511124373000_2026.01.29.702501v1.38","doi-asserted-by":"publisher","DOI":"10.1128\/aac.01350-22"},{"key":"2026020511124373000_2026.01.29.702501v1.39","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.M113.473371"}],"container-title":[],"original-title":[],"link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.64898\/2026.01.29.702501","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,2,5]],"date-time":"2026-02-05T19:12:57Z","timestamp":1770318777000},"score":1,"resource":{"primary":{"URL":"http:\/\/biorxiv.org\/lookup\/doi\/10.64898\/2026.01.29.702501"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,1,29]]},"references-count":39,"URL":"https:\/\/doi.org\/10.64898\/2026.01.29.702501","relation":{},"subject":[],"published":{"date-parts":[[2026,1,29]]},"subtype":"preprint"}}