Second messenger–mediated tactile response by a bacterial rotary motor

• Autores: Isabelle Hug, Siddharth Deshpande, Kathrin S. Sprecher
• Localización: Science, ISSN 0036-8075, Vol. 358, Nº 6362, 2017, págs. 531-534
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • When bacteria encounter surfaces, they respond with surface colonization and virulence induction. The mechanisms of bacterial mechanosensation and downstream signaling remain poorly understood. Here, we describe a tactile sensing cascade in Caulobacter crescentus in which the flagellar motor acts as sensor. Surface-induced motor interference stimulated the production of the second messenger cyclic diguanylate by the motor-associated diguanylate cyclase DgcB. This led to the allosteric activation of the glycosyltransferase HfsJ to promote rapid synthesis of a polysaccharide adhesin and surface anchoring. Although the membrane-embedded motor unit was essential for surface sensing, mutants that lack external flagellar structures were hypersensitive to mechanical stimuli. Thus, the bacterial flagellar motor acts as a tetherless sensor reminiscent of mechanosensitive channels.