Fig 1.
The co-infection of S. mutans and C. albicans promotes the process of caries.
The sulcal view of the maxillaries of the model rats, with arrows indicating representative caries lesions.
Table 1.
Statistical chart of the caries scores.
Fig 2.
Interaction between S. mutans and C. albicans via EMVs.
(A) Diagram of the transwell co-culture model depicting the spatial separation of S. mutans and C. albicans. (B) Influence of S. mutans on the Growth Kinetics of C. albicans. (C) Colony-Forming Units (CFU) of C. albicans. (D) Impact of S. mutans on C. albicans Biofilm Formation. (E) Biofilm biomass quantification of C. albicans. (F) TEM image of negative-stained S.m EMVs, highlighting spherical vesicles (indicated by white arrows). (G) NTA profile depicting the size distribution of S.m EMVs. (H) Fluorescent visualization of S.m EMVs (DiD, red) in co-culture with C. albicans cells (SYTO-9, green), indicating co-localization. (I) S.m EMVs’ effect on the planktonic growth of C. albicans. (J) Effect of S.m EMVs on biofilm formation of C. albicans. (K) Quantitative analysis of C. albicans biofilm biomass. S.m: Streptococcus mutans, C.a: Candida albicans, EMVs: Streptococcus mutans extracellular membrane vesicles, ****: P < 0.0001.
Fig 3.
(A) Left: Coomassie Brilliant Blue staining of total C. albicans proteins; Right: Immunoblot analysis of various post-translational modifications in total C. albicans proteins, highlighting ubiquitination patterns. (B) Left: Total protein staining of C. albicans; Right: Immunoblot of ubiquitination modifications in C. albicans proteins treated with S.m EMVs. S.m: Streptococcus mutans, C.a: Candida albicans, EMV: Streptococcus mutans extracellular membrane vesicles. EFS: EMVs-free supernatants of S. mutans cultures.
Fig 4.
Ubiquitination proteomics analysis of in C. albicans.
(A) Proteomics workflow for identifying and quantifying ubiquitinated proteins in C. albicans. (B) Statistical overview of ubiquitinated protein identification in C. albicans. (C-H) Various analyses depicting the ubiquitination landscape: peptide length distribution, motif analysis, subcellular localization, GO enrichment for cellular components, molecular functions, biological processes, and KEGG pathway enrichment.
Fig 5.
Differential Ubiquitination in C. albicans under S. mutans Co-Culture.
(A) Heatmap of differential ubiquitination modification sites. (B) Statistics of differential ubiquitination modifications and proteins. (C) GO enrichment analysis of proteins with altered ubiquitination. (D) Cluster and pathway analysis of proteins with differentially modified ubiquitination sites.
Fig 6.
Comprehensive Analysis of Proteomics and Ubiquitination Proteomics in C. albicans.
(A) Enrichment analysis of biological processes, cellular components and molecular functions of differential protein based on GO analysis. (B) Comparison of Ubiquitin (Ub) peptides and corresponding protein levels.
Fig 7.
S. mutans Mediates SOD3 Ubiquitination-Induced Degradation, Elevating Intracellular ROS Levels, and Promoting C. albicans Growth.
(A) Proteomics of C. albicans SOD3 ubiquitination. (B) MG132 inhibition of SOD3 degradation. (C) Western blot detection of SOD3 protein levels. (D) Intracellular ROS detection in C. albicans. (E) CRISPR/Cas9 construction of Δubi4 strain. (F) Morphological changes in Δubi4 strain. (G) Immunoblot of protein ubiquitination modifications. (H) ROS levels in C. albicans under S. mutans influence. (I) Impact of S. mutans on C. albicans growth and ROS modulation. S.m: Streptococcus mutans, C. a: Candida albicans, EMV: Streptococcus mutans extracellular membrane vesicles, NAC: N-Acetyl-L-cysteine antioxidant, *: P < 0.05, **: P < 0.01, ns: no statistically significant difference.
Fig 8.
Schematic showing a proposed model for the role of S. mutans in modulating ubiquitination of SOD3, influencing ROS levels, and potentially impacting growth of C. albicans.