Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Determinants of Bacterial Pathogenicity and Virulence01:20

Determinants of Bacterial Pathogenicity and Virulence

Pathogenic bacteria employ a variety of strategies to establish infections, including the secretion of extracellular enzymes that act as potent virulence factors. These enzymes facilitate bacterial colonization of host tissues and help evade immune surveillance. By targeting structural components of host tissues and interfering with immune mechanisms, these enzymes play a pivotal role in disease progression.Extracellular Enzymes Facilitating Tissue Invasion: Several bacterial pathogens secrete...
Streptococcal Pharyngitis01:27

Streptococcal Pharyngitis

Streptococcal pharyngitis, commonly known as “strep throat,” is an acute infection of the oropharyngeal tissues caused by the Gram‑positive Group A Streptococcus (Streptococcus pyogenes). Transmission occurs primarily through respiratory droplets expelled during coughing, sneezing, or talking.Mechanisms of Host Entry and Immune EvasionUpon entering the host, S. pyogenes adheres to the mucosal epithelial cells of the pharynx via surface proteins, notably lipoteichoic acid and the antiphagocytic...
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, normally used to...
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, normally used to...
Bacterial Meningitis II: Pathophysiology01:26

Bacterial Meningitis II: Pathophysiology

Bacterial meningitis typically begins when pathogens such as Neisseria meningitidis and Streptococcus pneumoniae colonize the nasopharynx and invade the bloodstream. This process is facilitated by bacterial virulence factors, such as polysaccharide capsules, which resist phagocytosis and complement-mediated killing. Less commonly, bacteria reach the central nervous system via contiguous spread from infections like otitis media or sinusitis, through congenital or acquired dural defects, or...
Fimbriae, Pili, and Axial Filaments01:28

Fimbriae, Pili, and Axial Filaments

Fimbriae and pili are specialized bacterial surface structures that play pivotal roles in adhesion, genetic exchange, and motility. Composed primarily of pilin protein, these hairlike appendages are crucial for bacterial survival and pathogenicity in various environments.Fimbriae: Adhesion and PathogenicityFimbriae are fine, filamentous structures measuring 2–10 nanometers in diameter and are densely distributed on the bacterial cell surface. They facilitate bacterial adhesion to abiotic...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

A microfluidic hollow-fiber infection model (µHFIM): monitoring bacterial response to dynamic drug treatment with single-cell resolution.

Microsystems & nanoengineering·2026
Same author

Staphylococcus aureus agr-type vs genetic background: molecular signatures determining differential metabolism and virulence potential.

PloS one·2026
Same author

Plasma membrane mediated GLUT10 mitochondrial targeting regulates intracellular ascorbic acid homeostasis.

iScience·2026
Same author

Single-cell approach dissecting agr quorum sensing dynamics in Staphylococcus aureus.

Nature communications·2026
Same author

Decoding sex and gender effects on health: evidence from a nationwide cohort.

Biology of sex differences·2026
Same author

Evaluation of the ELITe InGenius PCR assay compared with immunofluorescence for Pneumocystis jirovecii detection in respiratory samples.

European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology·2026

Related Experiment Video

Updated: Jun 3, 2026

Covalent Immobilization of Proteins for the Single Molecule Force Spectroscopy
11:13

Covalent Immobilization of Proteins for the Single Molecule Force Spectroscopy

Published on: August 20, 2018

Streptococcal M1 protein constructs a pathological host fibrinogen network.

Pauline Macheboeuf1, Cosmo Buffalo, Chi-yu Fu

  • 1Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, USA.

Nature
|April 9, 2011
PubMed
Summary

Streptococcus M1 protein forms a unique complex with fibrinogen, activating neutrophils and causing toxic shock-like symptoms. Understanding this structure reveals how the bacteria cause severe tissue injury.

More Related Videos

Implementation of a Permeable Membrane Insert-based Infection System to Study the Effects of Secreted Bacterial Toxins on Mammalian Host Cells
09:25

Implementation of a Permeable Membrane Insert-based Infection System to Study the Effects of Secreted Bacterial Toxins on Mammalian Host Cells

Published on: August 19, 2016

Related Experiment Videos

Last Updated: Jun 3, 2026

Covalent Immobilization of Proteins for the Single Molecule Force Spectroscopy
11:13

Covalent Immobilization of Proteins for the Single Molecule Force Spectroscopy

Published on: August 20, 2018

Implementation of a Permeable Membrane Insert-based Infection System to Study the Effects of Secreted Bacterial Toxins on Mammalian Host Cells
09:25

Implementation of a Permeable Membrane Insert-based Infection System to Study the Effects of Secreted Bacterial Toxins on Mammalian Host Cells

Published on: August 19, 2016

Area of Science:

  • Microbiology
  • Structural Biology
  • Immunology

Background:

  • Group A Streptococcus (GAS) is a leading cause of invasive infections.
  • M1 protein is a major GAS virulence factor responsible for toxic-shock-like symptoms.
  • Neutrophil activation is critical in the pathogenesis of streptococcal toxic shock.

Purpose of the Study:

  • To provide a structural explanation for the pathological properties of the M1-fibrinogen complex.
  • To elucidate the mechanism of M1-induced neutrophil activation.
  • To understand the structural basis of streptococcal toxic shock.

Main Methods:

  • X-ray crystallography to determine the structure of the M1-fibrinogen complex.
  • Biochemical assays to assess neutrophil activation.
  • Analysis of supramolecular network formation.

Main Results:

  • The M1 protein dimer organizes four fibrinogen molecules into a cross-like pattern.
  • This specific supramolecular network is essential for neutrophil activation.
  • Disruption of this network prevents pathological outcomes.
  • The network is distinct from a typical fibrin clot.

Conclusions:

  • The unique structure of the M1-fibrinogen complex explains its role in inducing vascular leakage and tissue injury.
  • Neutrophil activation is mediated by a specific supramolecular network formed by the complex.
  • These findings offer insights into the pathophysiology of streptococcal toxic shock.