Gene Regulation of Biofilm-Associated Functional Amyloids

Abstract

Biofilms are bacterial communities encased in a rigid yet dynamic extracellular matrix. The sociobiology of bacterial communities within a biofilm is astonishing, with environmental factors playing a crucial role in determining the switch from planktonic to a sessile form of life. The mechanism of biofilm biogenesis is an intriguingly complex phenomenon governed by the tight regulation of expression of various biofilm-matrix components. One of the major constituents of the biofilm matrix is proteinaceous polymers called amyloids. Since the discovery, the significance of biofilm-associated amyloids in adhesion, aggregation, protection, and infection development has been much appreciated. The amyloid expression and assembly is regulated spatio-temporarily within the bacterial cells to perform a diverse function. This review provides a comprehensive account of the genetic regulation associated with the expression of amyloids in bacteria. The stringent control ensures optimal utilization of amyloid scaffold during biofilm biogenesis. We conclude the review by summarizing environmental factors influencing the expression and regulation of amyloids.

The Amyloid Region of Hfq Riboregulator Promotes DsrA:rpoS RNAs Annealing

“…While amyloids are associated with diseases such as Alzheimer’s [ 48 ], they have also useful features [ 49 , 50 ]. This is, for instance, the case of bacterial amyloids that play important and positive roles for the cell [ 51 , 52 ]. Bacterial functional amyloids usually contain a particularly high prevalence of alanine, asparagine, and threonine, and this applies to Hfq-CTR [ 53 ].…”

Anti-Biofilm Molecules Targeting Functional Amyloids

“…In addition, CsgF interacts with CsgB, ensuring the attachment of the subunit on the cell surface and thus, the fiber formation [30]. CsgD controls at the transcriptional level the expression of the csgBAC operon [31,32] which is triggered by environmental and chemical signals such as osmolality, oxygen, and temperature [33,34]. Curli are implicated in surface colonization, cell-cell contact, biofilm matrix scaffolding, protection against antimicrobial agents and desiccation.…”

“…level the expression of the csgBAC operon [31,32] which is triggered by environmental and chemical signals such as osmolality, oxygen, and temperature [33,34]. Curli are implicated in surface colonization, cell-cell contact, biofilm matrix scaffolding, protection against antimicrobial agents and desiccation.…”

Identifying interaction interface betweenPseudomonasmajor biofilm forming functional amyloid FapC and disordered chaperone FapA during fibrillation deceleration

“…[8][9][10][11] For a detailed review on this topic, we refer the reader to recent reviews. 6,12 In recent years, there has been large interest in the functional amyloids, their biological roles and biophysical characterization. Despite abundant biophysical information available on functional amyloids, structural insights have been elusive due to the difficulties in studying either monomeric intrinsically disordered protein (IDP) forms or amyloids fibril forming macroscopic filaments.…”

“…7 Several biofilm-forming FuBAs, including CsgA from E. coli , FapC from Pseudomonas , TasA from B. subtilis , and PSMs from S. aureus , have been extensively studied, 8-11 summaries in recent reviews provide detailed insights. 6, 12…”