Role of the DksA-like protein in the pathogenesis and diverse metabolic activity of Campylobacter jejuni

Department of Food and Animal Biotechnology, School of Agricultural Biotechnology, and Center for Agricultural Biomaterials, Seoul National University, Seoul 151-921, Korea; Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA, 50011-1250

^* To whom correspondence should be addressed. Email: sangryu{at}snu.ac.kr.

	Abstract

DksA is well-known for its regulatory role in the transcription of ribosomal RNA and genes involved in amino acid synthesis in many bacteria. DksA is also reported to control expression of virulence genes in pathogenic bacteria. Here, we elucidated the roles of the DksA-like protein (CJJ81176_0160, Cj0125c) in the pathogenesis of Campylobacter jejuni. Like in other bacteria, transcription of stable RNA was repressed by the DksA-like protein under stressful conditions in C. jejuni. Transcriptomic and proteomic analyses of C. jejuni 81-176 and its isogenic mutant of the DksA-like protein showed differential expression of many genes involved in amino acid metabolism, iron-related metabolism, and other metabolic reactions. Also the C. jejuni mutant of the DksA-like protein demonstrated a decreased ability to invade intestinal cells and induce release of interleukin-8 from intestinal cells. These results suggest the DksA-like protein plays an important regulatory role in diverse metabolism and virulence of C. jejuni.