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Full-Text Articles in Organisms

Impacts Of A Duf2207 Family Protein On Streptococcus Mutans Stress Tolerance Responses And Biofilm Formation, Xiaochang Huang, Camile G. Laird, Paul P. Riley, Zezhang Tom Wen Aug 2023

Impacts Of A Duf2207 Family Protein On Streptococcus Mutans Stress Tolerance Responses And Biofilm Formation, Xiaochang Huang, Camile G. Laird, Paul P. Riley, Zezhang Tom Wen

School of Dentistry Faculty Publications

Locus SMU.243 in Streptococcus mutans was annotated as a member of the DUF2207 family proteins highly conserved in all bacteria but with unknown function. To investigate its role in S. mutans physiology, a SMU.243-deficient mutant was constructed using allelic exchange mutagenesis, and the impacts of SMU.243 deletion on bacterial growth, stress tolerance response, and biofilm formation were analyzed. Compared to the wild-type UA159, S. mutans lacking SMU.243 displayed a reduced growth rate and a reduced overnight culture density (p < 0.01) when grown at low pH and in the presence of methyl viologen. Relative to the parent strain, the deficient mutant also had a reduced survival rate following incubation in a buffer of pH 2.8 (p < 0.01) and in a buffer containing hydrogen peroxide at 58 mM after 60 min (p < 0.001) and had a reduced capacity in biofilm formation especially in the presence of sucrose (p < 0.01). To study any ensuing functional/phenotypical links between SMU.243 and uppP, which is located immediately downstream of SMU.243 and encodes an undecaprenyl pyrophosphate phosphatase involved in recycling of carrier lipid undecaprenyl phosphate, a uppP deficient mutant was generated using allelic exchange mutagenesis. Unlike the SMU.243 mutant, deletion of uppP affected cell envelope biogenesis and caused major increases in susceptibility to bacitracin. In addition, two variant morphological mutants, one forming rough colonies and the other forming mucoid, smooth colonies, also emerged following the deletion of uppP. The results suggest that the SMU.243-encoded protein of the DUF2207 family in S. mutans plays an important role in stress tolerance response and biofilm formation, but unlike the downstream uppP, does not seem to be involved in cell envelope biogenesis, although the exact roles in S. mutans’ physiology awaits further investigation.


Moerv14 Mediates The Intracellular Transport Of Cell Membrane Receptors To Govern The Appressorial Formation And Pathogenicity Of Magnaporthe Oryzae, Bin Qian, Xiaotong Su, Ziyuan Ye, Xinyu Liu, Muxing Liu, Haifeng Zhang, Ping Wang, Zhengguang Zhang Apr 2023

Moerv14 Mediates The Intracellular Transport Of Cell Membrane Receptors To Govern The Appressorial Formation And Pathogenicity Of Magnaporthe Oryzae, Bin Qian, Xiaotong Su, Ziyuan Ye, Xinyu Liu, Muxing Liu, Haifeng Zhang, Ping Wang, Zhengguang Zhang

School of Graduate Studies Faculty Publications

Magnaporthe oryzae causes rice blasts posing serious threats to food security worldwide. During infection, M. oryzae utilizes several transmembrane receptor proteins that sense cell surface cues to induce highly specialized infectious structures called appressoria. However, little is known about the mechanisms of intracellular receptor tracking and their function. Here, we described that disrupting the coat protein complex II (COPII) cargo protein MoErv14 severely affects appressorium formation and pathogenicity as the ΔMoerv14 mutant is defective not only in cAMP production but also in the phosphorylation of the mitogen-activated protein kinase (MAPK) MoPmk1. Studies also showed that either externally supplementing cAMP or …


Solid-State Nmr Analysis Of Unlabeled Fungal Cell Walls From Aspergillus And Candida Species, Liyanage D. Fernando, Malitha C. Dickwella Widanage, S. Chandra Shekar, Frederic Mentink-Vigier, Ping Wang, Sungsool Wi, Tuo Wang Jul 2022

Solid-State Nmr Analysis Of Unlabeled Fungal Cell Walls From Aspergillus And Candida Species, Liyanage D. Fernando, Malitha C. Dickwella Widanage, S. Chandra Shekar, Frederic Mentink-Vigier, Ping Wang, Sungsool Wi, Tuo Wang

School of Medicine Faculty Publications

Fungal infections cause high mortality in immunocompromised individuals, which has emerged as a significant threat to human health. The efforts devoted to the development of antifungal agents targeting the cell wall polysaccharides have been hindered by our incomplete picture of the assembly and remodeling of fungal cell walls. High-resolution solid-state nuclear magnetic resonance (ss NMR) studies have substantially revised our understanding of the polymorphic structure of polysaccharides and the nanoscale organization of cell walls in Aspergillus fumigatus and multiple other fungi. However, this approach requires 13C/15N-enrichment of the sample being studied, severely restricting its application. Here we employ the dynamic …