It is well known that salivary components can interact with microbes to influence their colonization of the oral cavity. One such interaction involves the abundant salivary enzyme, amylase, which binds specifically and with high affinity to commensal oral streptococci that are early colonizers of the saliva-coated tooth and numerous in supragingival dental plaque. Amylase-binding streptococci (ABS) colonize only hosts with detectable salivary amylase activity suggesting that amylase interactions modulate oral colonization by ABS and have an evolutionary basis. The ABS S. gordonii produces two amylase-binding proteins (ABPs) [AbpA (20-kDa) and AbpB (82-kDa) of Streptococcus gordonii. The binding of amylase to this species is dependent only on AbpA in S. gordonii (and likely its homologs in other species), and not on AbpB. In vitro studies found ABPs to play a role in bacterial adhesion and biofilm formation. Interestingly, AbpA defective S. gordonii mutants were able to colonize rat mouths as well as the parental strains, suggesting that additional bacterial factors are involved in colonization and survival in vivo. In light of these findings, we have considered potentially novel functions for these proteins. Preliminary studies suggest that amylase-binding to S. gordonii elicits differential gene expression in the bacterial cell. Thus, th Specific Aims of this proposal are to: 1: identify streptococcal components that interact with AbpA that may participate in a novel signaling pathway. 2: determine the three-dimensional structure of AbpA, identify amylase binding motifs and to address the evolutionary basis for the divergence of ABP gene sequence. 3: compare the global gene expression response of S. gordonii following binding of amylase to the response induced by the binding of whole- and ductal-saliva and other purified salivary components (such as mucins, sIgA, etc). Knowledge of saliva-mediated bacterial signaling pathways could have clinical application, for example by devising analog agents that serve as inhibitors or promoters of microbial colonization. Such agents may enable selective manipulation of bacterial colonization, and by extension, impact disease prevention or control. This knowledge could well extend beyond biofilm development in the oral cavity, with application to other microbial communities affecting systemic disease.

Public Health Relevance

Components of saliva are thought to contribute to the formation of dental plaque, the biofilm that forms on teeth that causes dental decay and gum disease. This proposal will address details of the mechanism by which an abundant enzyme in saliva, amylase, interacts with a common oral organism, Streptococcus gordonii and the function of this interaction. Understanding of this interaction could lead to new strategies to control dental plaque formation and thus prevent oral disease.

National Institute of Health (NIH)
National Institute of Dental & Craniofacial Research (NIDCR)
Research Project (R01)
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Oral, Dental and Craniofacial Sciences Study Section (ODCS)
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Lunsford, Dwayne
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State University of New York at Buffalo
Schools of Dentistry/Oral Hygn
United States
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Haase, Elaine M; Kou, Yurong; Sabharwal, Amarpreet et al. (2017) Erratum to: comparative genomics and evolution of the amylase-binding proteins of oral streptococci. BMC Microbiol 17:149
Haase, Elaine M; Kou, Yurong; Sabharwal, Amarpreet et al. (2017) Comparative genomics and evolution of the amylase-binding proteins of oral streptococci. BMC Microbiol 17:94
Liang, Xiaobo; Liu, Bing; Zhu, Fan et al. (2016) A distinct sortase SrtB anchors and processes a streptococcal adhesin AbpA with a novel structural property. Sci Rep 6:30966
Liao, Yu-Chieh; Lin, Hsin-Hung; Sabharwal, Amarpreet et al. (2015) MyPro: A seamless pipeline for automated prokaryotic genome assembly and annotation. J Microbiol Methods 113:72-4
Vickerman, M Margaret; Mansfield, Jillian M; Zhu, Min et al. (2015) Codon-optimized fluorescent mTFP and mCherry for microscopic visualization and genetic counterselection of streptococci and enterococci. J Microbiol Methods 116:15-22
Liu, Bing; Zhu, Fan; Wu, Hui et al. (2015) NMR assignment of the amylase-binding protein A from Streptococcus parasanguinis. Biomol NMR Assign 9:173-5
Haase, Elaine M; Feng, Xianghui; Pan, Jiachuan et al. (2015) Dynamics of the Streptococcus gordonii Transcriptome in Response to Medium, Salivary ?-Amylase, and Starch. Appl Environ Microbiol 81:5363-74
Sabharwal, Amarpreet; Liao, Yu-Chieh; Lin, Hsin-Hung et al. (2015) Draft genome sequences of 18 oral streptococcus strains that encode amylase-binding proteins. Genome Announc 3:
Maddi, A; Haase, Em; Scannapieco, Fa (2014) Mass Spectrometric Analysis of Whole Secretome and Amylase-precipitated Secretome Proteins from Streptococcus gordonii. J Proteomics Bioinform 7:287-295
Heo, Seok-Mo; Ruhl, Stefan; Scannapieco, Frank A (2013) Implications of salivary protein binding to commensal and pathogenic bacteria. J Oral Biosci 55:169-174

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