Regulation of adhesin synthesis in aggregatibacter actinomycetemcomitans

This study aimed to characterize the extracellular matrix protein adhesin A (EmaA) promoter region in Aggregatibacter actinomycetemcomitans, a Gram-negative bacterium associated with periodontal disease and extra-oral infections. The researchers used deletion constructs to identify two regions of the promoter sequence that regulate gene transcription and in silico analysis to identify multiple transcriptional regulatory binding sequences. They focused on four regulatory elements, CpxR, ArcA, OxyR, and DeoR. They found that the inactivation of arcA, a regulator of the ArcAB two-component signaling pathway involved in redox homeostasis, decreased EmaA synthesis and biofilm formation. The study suggests that these regulatory proteins coordinate the regulation of adhesins required for colonization and pathogenesis.