Medicine and Health Sciences Commons^™

Structural Modeling And Functional Analysis Of The Essential Ribosomal Processing Protease Prp From Staphylococcus Aureus, Erin A. Wall, Adam L. Johnson, Darrell L. Peterson, Gail E. Christie

Microbiology and Immunology Publications

In Firmicutes and related bacteria, ribosomal large subunit protein L27 is encoded with a conserved N-terminal extension that is removed to expose residues critical for ribosome function. Bacteria encoding L27 with this N-terminal extension also encode a sequence-specific cysteine protease, Prp, which carries out this cleavage. In this work, we demonstrate that L27 variants with an un-cleavable N-terminal extension, or lacking the extension (pre-cleaved), are unable to complement an L27 deletion in Staphylococcus aureus. This indicates that N-terminal processing of L27 is not only essential but possibly has a regulatory role. Prp represents a new clade of previously uncharacterized cysteine …

Tetr Family Regulator Brpt Modulates Biofilm Formation In Streptococcus Sanguinis, Jinlin Liu, Victoria N. Stone, Xiuchun Ge, Madison Tang, Fadi Elrami, Ping Xu

Microbiology and Immunology Publications

Biofilms are a key component in bacterial communities providing protection and contributing to infectious diseases. However, mechanisms involved in S. sanguinis biofilm formation have not been clearly elucidated. Here, we report the identification of a novel S. sanguinis TetR repressor, brpT (Biofilm Regulatory Protein TetR), involved in biofilm formation. Deletion of brpT resulted in a significant increase in biofilm formation. Interestingly, the mutant accumulated more water soluble and water insoluble glucans in its biofilm compared to the wild-type and the complemented mutant. The brpT mutation led to an altered biofilm morphology and structure exhibiting a rougher appearance, uneven …

Identification Of Naegleria Fowleri Proteins Linked To Primary Amoebic Meningoencephalitis, Melissa Jamerson, Jacqueline A. Schmoyer, Jay Park, Francine Marciano-Cabral, Guy A. Cabral

Microbiology and Immunology Publications

Naegleria fowleri (N. fowleri) causes primary amoebic meningoencephalitis, a rapidly fatal disease of the central nervous system. N. fowleri can exist in cyst, flagellate or amoebic forms, depending on environmental conditions. The amoebic form can invade the brain following introduction into the nasal passages. When applied intranasally to a mouse model, cultured N. fowleri amoebae exhibit low virulence. However, upon serial passage in mouse brain, the amoebae acquire a highly virulent state. In the present study, a proteomics approach was applied to the identification of N. fowleri amoeba proteins whose expression was associated with the highly virulent state …

Saikosaponins Induced Hepatotoxicity In Mice Via Lipid Metabolism Dysregulation And Oxidative Stress: A Proteomic Study, Xiaoyu Li, Xiaojiaoyang Li, Junxian Lu, Youyi Huang, Lili Lv, Yongfu Luan, Runping Liu, Rong Sun

Microbiology and Immunology Publications

Background

Radix Bupleuri (RB) has been popularly used for treating many liver diseases such as chronic hepatic inflammation and viral Hepatitis in China. Increasing clinical and experimental evidence indicates the potential hepatotoxicity of RB or prescriptions containing RB. Recently, Saikosaponins (SS) have been identified as major bioactive compounds isolated from RB, which may be also responsible for RB-induced liver injury.

Methods

Serum AST, ALT and LDH levels were determined to evaluate SS-induced liver injury in mice. Serum and liver total triglyceride and cholesterol were used to indicate lipid metabolism homeostasis. Liver ROS, GSH, MDA and iNOS were used to examine …