Role of DegQ in differential stability of flagellin subunits in Vibrio vulnificus

• Published in: NPJ biofilms and microbiomes Vol. 7; no. 1; p. 32
• Main Authors: Jung, You-Chul, Lee, Mi-Ae, Kim, Han-Shin, Lee, Kyu-Ho
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 08.04.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 631/326/1320; 631/326/46; Biofilms; Biomedical and Life Sciences; Developmental stages; Flagella; Flagellin; Life Sciences; Maturation; Medical Microbiology; Methionine; Microbial Ecology; Microbial Genetics and Genomics; Microbiology; Motility; Vibrio vulnificus
• ISSN: 2055-5008; 2055-5008
• DOI: 10.1038/s41522-021-00206-7

Biofilm formation of Vibrio vulnificus is initiated by adherence of flagellated cells to surfaces, and then flagellum-driven motility is not necessary during biofilm maturation. Once matured biofilms are constructed, cells become flagellated and swim to disperse from biofilms. As a consequence, timely regulations of the flagellar components’ expression are crucial to complete a biofilm life-cycle. In this study, we demonstrated that flagellins’ production is regulated in a biofilm stage-specific manner, via activities of a protease DegQ and a chaperone FlaJ. Among four flagellin subunits for V. vulnificus filament, FlaC had the highest affinities to hook-associated proteins, and is critical for maturating flagellum, showed the least susceptibility to DegQ due to the presence of methionine residues in its DegQ-sensitive domains, ND1 and CD0. Therefore, differential regulation by DegQ and FlaJ controls the cytoplasmic stability of flagellins, which further determines the motility-dependent, stage-specific development of biofilms.