Gene Expression Regulation of sRNA Hpnc2525 in the Clinically Relevant Helicobacter pylori cagPAI Genomic Region

Faculty Mentor

Andrea Castillo


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Document Type

Oral Presentation

Publication Date

Spring 5-27-2020




Helicobacter pylori is a common microaerophilic gram-negative bacterium that infects approximately 50% of the human population. Although all H. pylori infections result in inflammation of the gastric epithelium, only 10-15% of infections are symptomatic and progress to severe gastric diseases such as gastric and duodenal ulcers and gastric cancer. Different disease outcomes are due in part to genetic variations among H. pylori strains. Strains with a genomic region called the cytotoxin-associated pathogenicity island (cagPAI) are associated with an increased risk of severe disease. The cagPAI region encodes a type IV secretion system that transports the cagA effector into host gastric epithelial cells. Previous studies of other bacteria have found that sRNAs play a role in gene regulation. These transcripts are 50-300 nucleotides in length and act independently on expressed targets. Interactions serve to regulate and fine-tune gene expression by interacting with target mRNA molecules to inhibit or accelerate gene translation or function. Understanding how cagPAI genes are regulated is key to understanding how they promote disease. A previous study discovered three sRNAs located in cagPAI: Hpnc2665, Hpnc2525, and Hpnc2645. My goal is to understand what genes are regulated by Hpnc2525. Using a computational approach, the promoter and terminator sequence for Hpnc2525 has been identified. TargetRNA2, a computer prediction program, has narrowed down potential genes that may be regulated by Hpnc2525, engA and fliA. A GFP plasmid-based gene expression reporter system will be used to quantitatively analyze if expression of engA and fliA are regulated by Hpnc2525.

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