{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,18]],"date-time":"2026-03-18T10:02:44Z","timestamp":1773828164317,"version":"3.50.1"},"reference-count":30,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2025,11,28]],"date-time":"2025-11-28T00:00:00Z","timestamp":1764288000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Key R&D Program of Zhejiang","award":["2022C03060"],"award-info":[{"award-number":["2022C03060"]}]},{"DOI":"10.13039\/501100005356","name":"Zhejiang Shuren University","doi-asserted-by":"crossref","award":["202501001"],"award-info":[{"award-number":["202501001"]}],"id":[{"id":"10.13039\/501100005356","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pathogens"],"abstract":"<jats:p>Nicotinamide adenine dinucleotide (NAD+) serves as a critical cofactor in redox reactions and metabolic transformations catalyzed by NAD-dependent enzymes and is essential for bacterial survival and virulence. The biosynthesis of NAD+ in the cariogenic pathogen Streptococcus Sobrinus (S. sobrinus), a pivotal participant in oral cavities of children and adolescents with a history of caries, has yet to be explored. Bioinformatics, genetics, and biochemical techniques were used to identify NAD+ biosynthesis pathways and corresponding regulator in S. Sobrinus. S. sobrinus lacks de novo NAD+ synthesis pathway but comprises NA and Nam salvage pathway I (PncA-PncB-NadD-NadE) and PnuC-NadR salvage pathway III. NiaY and PnuC were involved in the salvage pathways. N-terminal domain of SsNrtR regulator was identified as DNA-binding domain binding to the pnuC and pncB probe, and addition of ADP-ribose reversed the binding of SsNrtR to the target promoters to regulate NAD+ salvage pathways. C-terminal domain of SsNrtR was non-catalytic, consistent with loss of Nudix motif conservation. Furthermore, the abrogation of niaR compromised multiple pathogenic traits, including cellular proliferation, acidogenesis, and the architecture\/mechanical integrity of biofilms. Consequently, this mutant exhibited attenuated virulence in a rat caries model. Our findings conclusively demonstrate that SsNrtR-mediated regulation of NAD+ homeostasis is a critical determinant of the cariogenic potential of S. sobrinus. This study identifies SsNrtR as a previously uncharacterized NAD+-responsive regulator that integrates metabolic homeostasis with the control of virulence in Streptococcus sobrinus. These findings elucidate a novel metabolic\u2013virulence regulatory axis in this species and position SsNrtR as a promising target for the development of anti-caries interventions.<\/jats:p>","DOI":"10.3390\/pathogens14121213","type":"journal-article","created":{"date-parts":[[2025,11,28]],"date-time":"2025-11-28T12:14:16Z","timestamp":1764332056000},"page":"1213","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Regulation of NAD+ Homeostasis by SsNrtR in Streptococcus Sobrinus: A Critical Determinant of Its Cariogenic Potential"],"prefix":"10.3390","volume":"14","author":[{"given":"Shuojie","family":"Lv","sequence":"first","affiliation":[{"name":"Key Laboratory of Artificial Organs and Computational Medicine of Zhejiang Province, Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Shulan International Medical College, Zhejiang Shuren University, Hangzhou 310015, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Haojie","family":"Yu","sequence":"additional","affiliation":[{"name":"Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou 310006, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dandan","family":"Shao","sequence":"additional","affiliation":[{"name":"Departments of Clinical Nutrition, The Second Affiliated Hospital of Zhejiang University, Hangzhou 310009, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yuheng","family":"Zhao","sequence":"additional","affiliation":[{"name":"College of Biology and Environmental Engineering, Zhejiang Shuren University, Hangzhou 310015, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jian","family":"Chen","sequence":"additional","affiliation":[{"name":"Key Laboratory of Artificial Organs and Computational Medicine of Zhejiang Province, Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Shulan International Medical College, Zhejiang Shuren University, Hangzhou 310015, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wanying","family":"Zheng","sequence":"additional","affiliation":[{"name":"Key Laboratory of Artificial Organs and Computational Medicine of Zhejiang Province, Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Shulan International Medical College, Zhejiang Shuren University, Hangzhou 310015, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Qingjing","family":"Wang","sequence":"additional","affiliation":[{"name":"Key Laboratory of Artificial Organs and Computational Medicine of Zhejiang Province, Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Shulan International Medical College, Zhejiang Shuren University, Hangzhou 310015, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,11,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1007\/s00018-003-3161-1","article-title":"Enzymology of NAD+ homeostasis in man","volume":"61","author":"Magni","year":"2004","journal-title":"Cell. Mol. Life Sci."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Chen, Y., Ying, Y., Lalsiamthara, J., Zhao, Y., Imani, S., Li, X., Liu, S., and Wang, Q. (2024). From bacteria to biomedicine: Developing therapies exploiting NAD+ metabolism. Bioorganic Chem., 142.","DOI":"10.1016\/j.bioorg.2023.106974"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2032","DOI":"10.1093\/nar\/gkn046","article-title":"Transcriptional regulation of NAD metabolism in bacteria: Genomic reconstruction of NiaR (YrxA) regulon","volume":"36","author":"Rodionov","year":"2008","journal-title":"Nucleic Acids Res."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"648","DOI":"10.1128\/JB.181.2.648-655.1999","article-title":"NAD-dependent DNA-binding activity of the bifunctional NadR regulator of Salmonella typhimurium","volume":"181","author":"Penfound","year":"1999","journal-title":"J. Bacteriol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2774","DOI":"10.1128\/JB.187.8.2774-2782.2005","article-title":"Regulation of NAD synthesis by the trifunctional NadR protein of Salmonella enterica","volume":"187","author":"Grose","year":"2005","journal-title":"J. Bacteriol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"7155","DOI":"10.1128\/JB.187.20.7155-7160.2005","article-title":"YrxA is the transcriptional regulator that represses de novo NAD biosynthesis in Bacillus subtilis","volume":"187","author":"Rossolillo","year":"2005","journal-title":"J. Bacteriol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2047","DOI":"10.1093\/nar\/gkn047","article-title":"Transcriptional regulation of NAD metabolism in bacteria: NrtR family of Nudix-related regulators","volume":"36","author":"Rodionov","year":"2008","journal-title":"Nucleic Acids Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1955","DOI":"10.1007\/s00784-015-1437-0","article-title":"Streptococcus mutans and Streptococcus sobrinus colonization and caries experience in 3- and 5-year-old Thai children","volume":"19","author":"Saraithong","year":"2015","journal-title":"Clin. Oral. Investig."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"402","DOI":"10.1159\/000262099","article-title":"Acid production by human strains of Streptococcus mutans and Streptococcus sobrinus","volume":"29","author":"Birkhed","year":"1995","journal-title":"Caries Res."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1159\/000261148","article-title":"Acidogenesis by oral streptococci at different pH values","volume":"23","author":"Toors","year":"1989","journal-title":"Caries Res."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"6055","DOI":"10.1096\/fj.201802179RR","article-title":"Functional definition of NrtR, a remnant regulator of NAD+ homeostasis in the zoonotic pathogen Streptococcus suis","volume":"33","author":"Wang","year":"2019","journal-title":"FASEB J."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"8746","DOI":"10.1128\/JB.01368-07","article-title":"Escherichia coli physiology in Luria-Bertani broth","volume":"189","author":"Sezonov","year":"2007","journal-title":"J. Bacteriol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"e00804-18","DOI":"10.1128\/MRA.00804-18","article-title":"Complete genome sequences of Streptococcus sobrinus SL1 (ATCC 33478 = DSM 20742), NIDR 6715-7 (ATCC 27351), NIDR 6715-15 (ATCC 27352), and NCTC 10919 (ATCC 33402)","volume":"7","author":"Sales","year":"2018","journal-title":"Microbiol. Resour. Announc."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Chang, J.C., LaSarre, B., Jimenez, J.C., Aggarwal, C., and Federle, M.J. (2011). Two group a streptococcal peptide pheromones act through opposing Rgg regulators to control biofilm development. PLoS Pathog., 7.","DOI":"10.1371\/annotation\/a41fff48-2a84-4cb8-b27c-afd14bcd40f0"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Zhou, J., Li, S., Li, H., Jin, Y., Bai, F., Cheng, Z., and Wu, W. (2021). Identification of a toxin-antitoxin system that contributes to persister formation by reducing NAD in Pseudomonas aeruginosa. Microorganisms, 9.","DOI":"10.3390\/microorganisms9040753"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1088","DOI":"10.1177\/00220345580370060901","article-title":"Dental caries in the molar teeth of rats. II. A method for diagnosing and scoring several types of lesions simultaneously","volume":"37","author":"Keyes","year":"1958","journal-title":"J. Dent. Res."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"3012","DOI":"10.1128\/JB.188.8.3012-3023.2006","article-title":"Comparative genomics of NAD biosynthesis in cyanobacteria","volume":"188","author":"Gerdes","year":"2006","journal-title":"J. Bacteriol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"6906","DOI":"10.1128\/JB.184.24.6906-6917.2002","article-title":"Ribosylnicotinamide kinase domain of NadR protein: Identification and implications in NAD biosynthesis","volume":"184","author":"Kurnasov","year":"2002","journal-title":"J. Bacteriol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"3785","DOI":"10.1128\/jb.178.13.3785-3790.1996","article-title":"Changes in patterns of ADP-ribosylated proteins during differentiation of streptomyces coelicolor A3(2) and its development mutants","volume":"178","author":"Shima","year":"1996","journal-title":"J. Bacteriol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"939","DOI":"10.1016\/j.str.2009.05.012","article-title":"Structure and function of an ADP-ribose-dependent transcriptional regulator of NAD metabolism","volume":"17","author":"Huang","year":"2009","journal-title":"Structure"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"25059","DOI":"10.1074\/jbc.271.41.25059","article-title":"The MutT proteins or \u201cNudix\u201d hydrolases, a family of versatile, widely distributed, \u201chousecleaning\u201d enzymes","volume":"271","author":"Bessman","year":"1996","journal-title":"J. Biol. Chem."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"245","DOI":"10.1016\/S1570-9639(04)00069-X","article-title":"Identification and characterization of NuhA, a novel Nudix hydrolase specific for ADP-ribose in the cyanobacterium Synechococcus sp. PCC 7002","volume":"1699","author":"Okuda","year":"2004","journal-title":"Biochim. Biophys. Acta"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"39490","DOI":"10.1074\/jbc.M110.185629","article-title":"Genomics-driven reconstruction of acinetobacter NAD metabolism: Insights for antibacterial target selection","volume":"285","author":"Sorci","year":"2010","journal-title":"J. Biol. Chem."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"4295","DOI":"10.1073\/pnas.90.9.4295","article-title":"PutA protein, a membrane-associated flavin dehydrogenase, acts as a redox-dependent transcriptional regulator","volume":"90","author":"Maloy","year":"1993","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"5509","DOI":"10.1128\/JB.181.17.5509-5511.1999","article-title":"The Escherichia coli NadR regulator is endowed with nicotinamide mononucleotide adenylyltransferase activity","volume":"181","author":"Raffaelli","year":"1999","journal-title":"J. Bacteriol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"83","DOI":"10.1016\/j.ijmm.2016.09.007","article-title":"Key role of an ADP\u2014Ribose\u2014Dependent transcriptional regulator of NAD metabolism for fitness and virulence of Pseudomonas aeruginosa","volume":"307","author":"Okon","year":"2017","journal-title":"Int. J. Med. Microbiol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"2127","DOI":"10.1099\/mic.0.000164","article-title":"Characterization of NAD salvage pathways and their role in virulence in Streptococcus pneumoniae","volume":"161","author":"Johnson","year":"2015","journal-title":"Microbiology"},{"key":"ref_28","first-page":"303","article-title":"Comparative virulence of NAD-dependent and NAD-independent Actinobacillus pleuropneumoniae strains","volume":"39","author":"Dom","year":"1992","journal-title":"Zentralbl Vet. B"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Jin, Y., Zhang, M., Zhu, F., Peng, Q., Weng, Y., Zhao, Q., Liu, C., Bai, F., Cheng, Z., and Jin, S. (2019). NrtR regulates the type III secretion system through cAMP\/Vfr pathway in Pseudomonas aeruginosa. Front. Microbiol., 10.","DOI":"10.3389\/fmicb.2019.00085"},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Zhang, X., Yin, L., Liu, Q., Wang, D., Xu, C., Pan, X., Bai, F., Cheng, Z., Wu, W., and Jin, Y. (2022). NrtR mediated regulation of H1-T6SS in Pseudomonas aeruginosa. Microbiol. Spectr., 10.","DOI":"10.1128\/spectrum.01858-21"}],"container-title":["Pathogens"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-0817\/14\/12\/1213\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,18]],"date-time":"2026-03-18T07:51:09Z","timestamp":1773820269000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-0817\/14\/12\/1213"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,11,28]]},"references-count":30,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2025,12]]}},"alternative-id":["pathogens14121213"],"URL":"https:\/\/doi.org\/10.3390\/pathogens14121213","relation":{},"ISSN":["2076-0817"],"issn-type":[{"value":"2076-0817","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,11,28]]}}}