Related Experiment Video

Updated: Feb 8, 2026

Methods for Detecting Cytotoxic Amyloids Following Infection of Pulmonary Endothelial Cells by Pseudomonas aeruginosa
07:27

Methods for Detecting Cytotoxic Amyloids Following Infection of Pulmonary Endothelial Cells by Pseudomonas aeruginosa

Published on: July 12, 2018

5.9K

Protein Engineering Reveals Mechanisms of Functional Amyloid Formation in Pseudomonas aeruginosa Biofilms

Alissa Bleem1, Gunna Christiansen2, Daniel J Madsen3

  • 1Department of Bioengineering, University of Washington, Seattle, WA 98195, USA.

Journal of Molecular Biology
|July 3, 2018
PubMed

Insights

Bacteria use functional amyloid fibrils to resist antibiotics. Researchers identified key protein motifs in Pseudomonas aeruginosa that drive amyloid formation, crucial for biofilm defense and potential new drug targets.

Area of Science:

  • Microbiology
  • Biochemistry
  • Structural Biology

Background:

  • Amyloids, typically linked to neurodegenerative diseases, also play functional roles in bacteria.
  • Bacterial amyloids fortify biofilms, enhancing resistance to antibiotic treatments.
  • Pseudomonas aeruginosa utilizes FapC protein for major amyloid fibril formation in its biofilm.

Purpose of the Study:

  • To investigate the mechanism of FapC amyloid fibril formation in Pseudomonas aeruginosa.
  • To identify specific sequence motifs within FapC that are critical for amyloidogenesis.
  • To explore the potential for targeting these motifs to inhibit biofilm formation.

Main Methods:

  • Bioinformatic analysis of the FapC protein sequence.
  • Protein engineering to mutate identified amyloidogenic motifs.
  • In vitro assessment of fibril formation and oligomerization.
  • pH-dependent analysis of FapC aggregation.

Main Results:

  • Identified conserved and amyloidogenic motifs within the FapC sequence.
  • Demonstrated that mutating these motifs suppresses fibril formation in a pH-dependent manner.
  • Highlighted the critical role of the third repeat motif in promoting fibril formation.
  • Observed the early emergence of soluble oligomer species during the aggregation pathway.

Conclusions:

  • Elucidated key sequence determinants of FapC amyloid polymerization in P. aeruginosa.
  • Provided insights into the mechanism of functional bacterial amyloid formation.
  • Established a foundation for developing novel inhibitors against antibiotic-resistant bacterial biofilms.
Keywords:
bacterial amyloidextracellular matrixpeptide microarrayprotein aggregationprotein sequence analysis

More Related Videos

Pseudomonas aeruginosa and Saccharomyces cerevisiae Biofilm in Flow Cells17:30

Pseudomonas aeruginosa and Saccharomyces cerevisiae Biofilm in Flow Cells

Published on: January 15, 2011

37.7K
Co-culture Models of Pseudomonas aeruginosa Biofilms Grown on Live Human Airway Cells11:21

Co-culture Models of Pseudomonas aeruginosa Biofilms Grown on Live Human Airway Cells

Published on: October 6, 2010

22.8K

Related Concept Videos

Mechanical Protein Functions01:58

Mechanical Protein Functions

Proteins perform many mechanical functions in a cell. These proteins can be classified into two general categories- proteins that generate mechanical forces and proteins that are subjected to mechanical forces. Proteins providing mechanical support to the structure of the cell, such as keratin, are subjected to mechanical force, whereas proteins involved in cell movement and transport of molecules across cell membranes, such as an ion pump, are examples of generating mechanical force. 
5.7K
Amyloid Fibrils03:03

Amyloid Fibrils

Amyloid fibrils are aggregates of misfolded proteins.  Under most circumstances, misfolded proteins are either refolded by chaperone proteins or degraded by the proteasome. However, in the case of a mutation or a disease, these proteins can accumulate to form large clusters and often further assemble to form elongated fibers, called fibrils. 
Amyloid deposits were observed as early as 1639 in the liver and the spleen.   In 1854, Rudolph Virchow performed iodine staining,...
12.0K
Mechanical Protein Function01:58

Mechanical Protein Function

2.5K
Mechanism of Lamellipodia Formation01:31

Mechanism of Lamellipodia Formation

Cells migrating in response to external stimuli form lamellipodia, which are thin membrane protrusions supported by a mesh of linked, branched, or unbranched actin filaments. These actin filaments interact with myosin motor proteins, creating the dynamic actomyosin complex within the cytoskeleton. Contractility, or the ability to generate contractile stress, is inherent to the actomyosin complex. It helps cells detect the stiffness of the surrounding ECM and exert contractile force for...
3.7K
Mechanism of Filopodia Formation01:39

Mechanism of Filopodia Formation

Filopodia are thin, actin-rich cellular protrusions that play an important role in many fundamental cellular functions. They vary in their occurrence, length, and positioning in different cell types, suggesting their diverse roles.
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
3.2K
Mechanisms of Membrane Domain Formation00:59

Mechanisms of Membrane Domain Formation

Different physical properties of lipids and proteins allow them to localize and form distinct islands or domains in the membrane. Some membrane domains are formed due to protein-protein interactions, whereas others are formed due to the presence of specific lipids such as sphingolipids and sterols—for example, large proteins, such as bacteriorhodopsin, aggregate and create distinct domains.
Another mechanism for membrane domain formation involves membrane proteins interacting with...
3.9K