Laboratoire d'Ingénierie des Systèmes Macromoléculaires, CNRS - Aix Marseille Université, 31 Chemin Joseph Aiguier, Marseille, France.
Environ Microbiol. 2011 Mar;13(3):666-83. doi: 10.1111/j.1462-2920.2010.02372.x. Epub 2010 Nov 22.
The opportunistic pathogen Pseudomonas aeruginosa has redundant molecular systems that contribute to its pathogenicity. Those assembling fimbrial structures promote complex organized community lifestyle. We characterized a new 5.8 kb genetic locus, cupE, that includes the conserved usher- and chaperone-encoding genes. This locus, widely conserved in different bacterial species, contains four additional genes encoding non-archetypal fimbrial subunits. We first evidenced that the cupE gene cluster was specifically expressed in biofilm conditions and was responsible for fibre assembly containing at least CupE1 protein, at the bacterial cell surface. These fimbriae not only played a significant role in the early stages (microcolony and macrocolony formation) but also in shaping 3D mushrooms during P. aeruginosa biofilm development. Using wide-genome transposon mutagenesis, we identified the PprAB two-component system (TCS) as a regulator of cupE expression, and further demonstrated the involvement of the PprAB TCS in direct CupE fimbrial assembly activation. Thus, this TCS represents a new regulatory element controlling the transition between planktonic and community lifestyles in P. aeruginosa.
机会性病原体铜绿假单胞菌具有冗余的分子系统，这些系统有助于其致病性。那些组装菌毛结构的系统促进了复杂的有组织的社区生活方式。我们描述了一个新的 5.8 kb 遗传基因座 cupE，该基因座包含保守的 usher 和 chaperone 编码基因。该基因座在不同的细菌物种中广泛保守，包含另外四个编码非典型菌毛亚基的基因。我们首先证明 cupE 基因簇在生物膜条件下特异性表达，并负责在细菌细胞表面组装纤维，至少包含 CupE1 蛋白。这些菌毛不仅在早期（微菌落和大菌落形成）阶段发挥了重要作用，而且在铜绿假单胞菌生物膜发育过程中也对 3D 蘑菇的形成起到了重要作用。通过广泛的基因组转座子诱变，我们确定了 PprAB 双组分系统（TCS）是 cupE 表达的调节剂，并进一步证明了 PprAB TCS 参与了直接 CupE 菌毛组装的激活。因此，该 TCS 代表了一个新的调控元件，控制铜绿假单胞菌从浮游和社区生活方式之间的转变。
