Identifying Protein Motifs in Cas9 Essential for Bacterial Virulence
Abstract
Critical Problem: Bacterial infections are a serious threat to human health. The advances in developing new antibiotics have slowed down recently. In addition, several bacteria are developing antibiotic resistance at alarming rates. Thus, there is a critical need for developing novel approaches and targets for antibacterial development. Characterizing a novel protein target for each specific bacterial infection is a time-consuming process. An attractive strategy is to identify a new antimicrobial target that has been implicated in pathogenicity of several harmful bacteria. Towards this, we propose Cas9 as a novel target for antibacterial development since several studies in multiple human pathogenic bacteria have demonstrated the need of Cas9 in virulence and host cell invasion mechanisms. Additionally, since Cas9 is predominantly present in pathogenic bacteria, and not in commensal and environmental bacteria, a drug targeting Cas9 provides an avenue to remove harmful effects following an antibiotic treatment regime. The proposed work closely relates to the Peer Reviewed Medical Research Program Topic Area of Respiratory Health and Pulmonary Fibrosis and the Strategic Goal of develop and test novel treatments to slow progression or reverse lung injury/disease since streptococci, the causative agent of respiratory and pulmonary diseases, possess Cas9. The idea can also be related to Topic Area of Guillain-Barré Syndrome, and Inflammatory Bowel Diseases, since its causative agent, Campylobacter, uses Cas9 to infect the host. Innovation: The most innovative aspect of the proposed study is using Cas9 as a universal protein to tackle harmful bacterial infections, with minimal impact on beneficial bacteria due to the unique protein sequence patterns of Cas9 between these groups of bacteria. Our preliminary data analyzed sequence patterns of Cas9 using computational approaches, including the use of artificial intelligence, and have identified sequence patterns (termed motifs) that are unique to pathogenic and environmental bacteria with great statistical significance. In the proposed work, we will use computational methods for reliable identification of unique motifs from Cas9 belonging to three unique habitats (pathogenic, commensal, and environmental). Unique motifs selected for pathogenic bacteria will be tested experimentally using Streptococcus pyogenes as the model organism since it is involved in respiratory health and pulmonary fibrosis. The combinatorial use of computational and experimental approaches is advantageous than the cumbersome, unguided experimental approaches. Applicability: CRISPR-Cas systems were discovered as bacterial immune systems where intruding viruses are cleaved by sequence-specifically by protein-RNA complexes belonging to this system. Interestingly, emerging studies show that Cas9, a protein component of the CRISPR system, can regulate other bacterial processes, such as virulence. Currently, fundamental mechanisms by which Cas9 regulates bacterial virulence and regions of Cas9 that are specific to virulence, but not contributing to viral protection, are unknown. Cas9 being a large, multi-domain protein, identifying unique pockets related to virulence will enable targeted drug development. The proposed study will address this by large-scale bioinformatics and machine learning studies across several bacteria belonging to different habitats to identify Cas9 motifs that are unique among them. The effect of the identified motifs in virulence will be tested experimentally using streptococcus. If established, the pathogenic motifs can be targeted for novel antimicrobial strategies against several harmful bacteria, without impacting beneficial bacteria. Impact: The main impact will be developing Cas9 as a universal molecule to treat infections that are caused by divergent bacteria. Several of the devastating diseases affecting military and civilian communities as well as issues related to a
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 04, 2024
- Source ID
- HT94252310256
Entities
People
- Rakhi Rajan
Organizations
- United States Army
- University of Oklahoma