The Production of Curli Amyloid Fibers Is Deeply Integrated into the Biology of Escherichia coli

نویسندگان

  • Daniel R. Smith
  • Janet E. Price
  • Peter E. Burby
  • Luz P. Blanco
  • Justin Chamberlain
  • Matthew R. Chapman
چکیده

Curli amyloid fibers are the major protein component of the extracellular matrix produced by Enterobacteriaceae during biofilm formation. Curli are required for proper biofilm development and environmental persistence by Escherichia coli. Here, we present a complete and vetted genetic analysis of functional amyloid fiber biogenesis. The Keio collection of single gene deletions was screened on Congo red indicator plates to identify E. coli mutants that had defective amyloid production. We discovered that more than three hundred gene products modulated curli production. These genes were involved in fundamental cellular processes such as regulation, environmental sensing, respiration, metabolism, cell envelope biogenesis, transport, and protein turnover. The alternative sigma factors, σS and σE, had opposing roles in curli production. Mutations that induced the σE or Cpx stress response systems had reduced curli production, while mutant strains with increased σS levels had increased curli production. Mutations in metabolic pathways, including gluconeogenesis and the biosynthesis of lipopolysaccharide (LPS), produced less curli. Regulation of the master biofilm regulator, CsgD, was diverse, and the screen revealed several proteins and small RNAs (sRNA) that regulate csgD messenger RNA (mRNA) levels. Using previously published studies, we found minimal overlap between the genes affecting curli biogenesis and genes known to impact swimming or swarming motility, underlying the distinction between motile and sessile lifestyles. Collectively, the diversity and number of elements required suggest curli production is part of a highly regulated and complex developmental pathway in E. coli.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Role of Escherichia coli curli operons in directing amyloid fiber formation.

Amyloid is associated with debilitating human ailments including Alzheimer's and prion diseases. Biochemical, biophysical, and imaging analyses revealed that fibers produced by Escherichia coli called curli were amyloid. The CsgA curlin subunit, purified in the absence of the CsgB nucleator, adopted a soluble, unstructured form that upon prolonged incubation assembled into fibers that were indi...

متن کامل

Congo Red Interactions with Curli-Producing E. coli and Native Curli Amyloid Fibers

Microorganisms produce functional amyloids that can be examined and manipulated in vivo and in vitro. Escherichia coli assemble extracellular adhesive amyloid fibers termed curli that mediate adhesion and promote biofilm formation. We have characterized the dye binding properties of the hallmark amyloid dye, Congo red, with curliated E. coli and with isolated curli fibers. Congo red binds to cu...

متن کامل

The Ability of Cellulose Polysaccharide and Curli Pili Production in Uropathogenic Escherichia Coli and its Association with Biofilm Formation Intensity

Abstract        Background and Objective: the Formation of urinary infection by uropathogenic E.coli needs   numerous virulence factors and biofilm formation is among these factors. Bacteria that form biofilms express phenotype traits that appear according to the bacteria type. Cellulose is an important compound on the outside of E.coli causing bacte...

متن کامل

The Bacterial Amyloid Curli Is Associated with Urinary Source Bloodstream Infection

Urinary tract infections are the most common cause of E. coli bloodstream infections (BSI) but the mechanism of bloodstream invasion is poorly understood. Some clinical isolates have been observed to shield themselves with extracellular amyloid fibers called curli at physiologic temperature. We hypothesize that curli fiber assembly at 37 °C promotes bacteremic progression by urinary E. coli str...

متن کامل

Nucleation and growth of a bacterial functional amyloid at single fiber resolution

Curli are functional amyloids produced by proteobacteria like Escherichia coli as part of the extracellular matrix that holds cells together into biofilms. The molecular events that occur during curli nucleation and fiber extension remain largely unknown. Combining observations from curli amyloidogenesis in bulk solutions with real-time in situ nanoscopic imaging at the single-fiber level, we s...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره 7  شماره 

صفحات  -

تاریخ انتشار 2017