Glucose induces delocalization of a flagellar biosynthesis protein from the flagellated pole

• Published in: Molecular microbiology Vol. 101; no. 5; pp. 795 - 808
• Main Authors: Park, Soyoung, Park, Young‐Ha, Lee, Chang‐Ro, Kim, Yeon‐Ran, Seok, Yeong‐Jae
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01.09.2016
• Subjects: Bacterial proteins; Bacterial Proteins - metabolism; Biosynthesis; Cell Movement - physiology; Chemotaxis - physiology; Enterobacteriaceae; Escherichia coli Proteins - biosynthesis; Escherichia coli Proteins - metabolism; Flagella - metabolism; Glucose; Glucose - metabolism; Glucose - pharmacology; Microbiology; Motility; Phosphoenolpyruvate Sugar Phosphotransferase System - biosynthesis; Phosphoenolpyruvate Sugar Phosphotransferase System - metabolism; Phosphorylation; Protein Biosynthesis; Vibrio vulnificus; Vibrio vulnificus - metabolism
• ISSN: 0950-382X; 1365-2958
• DOI: 10.1111/mmi.13424

Summary To survive in a continuously changing environment, bacteria sense concentration gradients of attractants or repellents, and purposefully migrate until a more favourable habitat is encountered. While glucose is known as the most effective attractant, the flagellar biosynthesis and hence chemotactic motility has been known to be repressed by glucose in some bacteria. To date, the only known regulatory mechanism of the repression of flagellar synthesis by glucose is via downregulation of the cAMP level, as shown in a few members of the family Enterobacteriaceae. Here we show that, in Vibrio vulnificus, the glucose‐mediated inhibition of flagellar motility operates by a completely different mechanism. In the presence of glucose, EIIAGlc is dephosphorylated and inhibits the polar localization of FapA (flagellar assembly protein A) by sequestering it from the flagellated pole. A loss or delocalization of FapA results in a complete failure of the flagellar biosynthesis and motility. However, when glucose is depleted, EIIAGlc is phosphorylated and releases FapA such that free FapA can be localized back to the pole and trigger flagellation. Together, these data provide new insight into a bacterial strategy to reach and stay in the glucose‐rich area. Making a right decision to stay or move is critical for survival in a changing environment. Here we identify a novel mechanism for glucose‐dependent on‐off switching of flagellar synthesis in Vibrio vulnificus: When enzyme IIAGlc of the bacterial PEP:carbohydrate phosphotransferase system is dephosphorylated in the presence glucose, it delocalizes a protein required for flagellar biosynthesis from the flagellated pole. This leads to a loss of motility and enables bacteria to stay in a favorable habitat.