The Diverse Roles of the Histone‐Like Nucleoid Structuring (H‐NS) Protein in Vibrio parahaemolyticus

The histone‐like nucleoid structuring (H‐NS) protein is a global transcriptional regulator critical for bacterial genome organization and gene expression. In Vibrio parahaemolyticus , H‐NS represses virulence factors such as thermostable direct hemolysin (TDH), type III secretion systems (T3SS1/T3SS2), and type VI secretion systems (T6SS1/T6SS2). It also modulates swimming motility by activating polar flagellar genes while repressing swarming motility and lateral flagellar systems. Additionally, H‐NS influences biofilm formation through regulation of exopolysaccharide synthesis and cyclic di‐GMP (c‐di‐GMP) metabolism. Emerging evidence suggests cross‐regulation with quorum sensing (QS) systems, though direct mechanistic insights into V. parahaemolyticus remain sparse. Furthermore, a recent study indicates H‐NS roles extend to osmotic stress adaptation, such as regulating the ectoine biosynthetic pathway. This review synthesizes current knowledge on H‐NS‐mediated regulation in V. parahaemolyticus and offers new insights for future research.