Chaperones mainly suppress primary nucleation during formation of functional amyloid required for bacterial biofilm formation

Madhu Nagaraj, Zahra Najarzadeh, Jonathan Pansieri, Henrik Biverstål, Greta Musteikyte, Vytautas Smirnovas, Steve Matthews, Cecilia Emanuelsson, Janne Johansson, Joel N Buxbaum, Ludmilla Morozova-Roche, Daniel E Otzen*

*Corresponding author af dette arbejde

Publikation: Bidrag til tidsskrift/Konferencebidrag i tidsskrift /Bidrag til avisTidsskriftartikelForskningpeer review


Unlike misfolding in neurodegenerative diseases, aggregation of functional amyloids involved in bacterial biofilm, e.g. CsgA (E. coli) and FapC (Pseudomonas), is carefully regulated. However, it is unclear whether functional aggregation is inhibited by chaperones targeting pathological misfolding and if so by what mechanism. Here we analyze how four entirely different human chaperones or protein modulators (transthyretin, S100A9, Bri2 BRICHOS and DNAJB6) and bacterial CsgC affect CsgA and FapC fibrillation. CsgA is more susceptible to inhibition than FapC and the chaperones vary considerably in the efficiency of their inhibition. However, mechanistic analysis reveals that all predominantly target primary nucleation rather than elongation or secondary nucleation, while stoichiometric considerations suggest that DNAJB6 and CsgC target nuclei rather than monomers. Inhibition efficiency broadly scales with the chaperones' affinity for monomeric CsgA and FapC. The chaperones tend to target the most aggregation-prone regions of CsgA, but do not display such tendencies towards the more complex FapC sequence. Importantly, the most efficient inhibitors (Bri2 BRICHOS and DNAJB6) significantly reduce bacterial biofilm formation. This commonality of chaperone action may reflect the simplicity of functional amyloid formation, driven largely by primary nucleation, as well as the ability of non-bacterial chaperones to deploy their proteostatic capacities across biological kingdoms.

TidsskriftChemical Science
Sider (fra-til)536-553
Antal sider18
StatusUdgivet - jan. 2022


Dyk ned i forskningsemnerne om 'Chaperones mainly suppress primary nucleation during formation of functional amyloid required for bacterial biofilm formation'. Sammen danner de et unikt fingeraftryk.