Related Experiment Video

Updated: Aug 11, 2026

4D Imaging of Protein Aggregation in Live Cells
08:59

4D Imaging of Protein Aggregation in Live Cells

Published on: April 5, 2013

Accelerated protein aggregation induced by macrophage migration inhibitory factor under heat stress conditions

O A Cherepkova1, E M Lyutova, T B Eronina

  • 1Bach Institute of Biochemistry, Russian Academy of Sciences, 119071 Moscow, Russia.

Biochemistry. Biokhimiia
|February 24, 2006
PubMed

Insights

Macrophage migration inhibitory factor (MIF) accelerates protein aggregation under heat stress but can also promote protein refolding upon removal of stress. This suggests MIF exhibits dual anti-chaperone and chaperone-like activities.

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Protein Chemistry

Background:

  • Protein aggregation is a hallmark of cellular stress.
  • Macrophage Migration Inhibitory Factor (MIF) is a heat-stable protein implicated in various biological processes.
  • Understanding protein-MIF interactions is crucial for cellular homeostasis.

Purpose of the Study:

  • To investigate the kinetics of thermal protein aggregation in the presence of MIF.
  • To determine the effect of MIF on protein refolding after heat stress.
  • To elucidate the dual role of MIF in protein stability.

Main Methods:

  • Turbidimetry to monitor protein aggregation kinetics.
  • Spectroscopic analysis of protein aggregation.
  • Investigated model proteins: glycogen phosphorylase b and yeast alcohol dehydrogenase.
  • Applied heat stress (41-48°C) and physiological temperature (41.5°C).

Main Results:

  • MIF demonstrated significant anti-chaperone activity, accelerating protein aggregation.
  • Aggregation kinetics exhibited cooperative behavior.
  • Reversibility of aggregation was observed upon removal of heat stress, indicating refolding.
  • MIF binding stabilized oligomeric structures of partially denatured proteins.

Conclusions:

  • MIF possesses a dual activity: it promotes aggregation under stress but aids refolding upon stress removal.
  • MIF's anti-chaperone effect is prominent during heat stress.
  • MIF can exhibit chaperone-like activity, facilitating protein recovery under normal conditions.

More Related Videos

Extraction and Visualization of Protein Aggregates after Treatment of Escherichia coli with a Proteotoxic Stressor07:59

Extraction and Visualization of Protein Aggregates after Treatment of Escherichia coli with a Proteotoxic Stressor

Published on: June 29, 2021

Studying the Protein Quality Control System of D. discoideum Using Temperature-controlled Live Cell Imaging06:09

Studying the Protein Quality Control System of D. discoideum Using Temperature-controlled Live Cell Imaging

Published on: December 2, 2016

Related Concept Videos

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 Protein Maturation01:26

Bacterial Protein Maturation

Bacterial protein maturation is a tightly regulated process that ensures newly synthesized polypeptides achieve correct functional conformations. This maturation involves a series of modifications, folding events, and quality control steps, often assisted by specialized chaperone proteins.N-Terminal ModificationsThe maturation of bacterial polypeptides begins cotranslationally as the polypeptide exits the ribosome. The first amino acid, N-formylmethionine (fMet), is typically modified at the...
Molecular Chaperones and Protein Folding03:00

Molecular Chaperones and Protein Folding

The native conformation of a protein is formed by interactions between the side chains of its constituent amino acids. When the amino acids cannot form these interactions, the protein cannot fold by itself and needs chaperones. Notably, chaperones do not relay any additional information required for the folding of polypeptides; the native conformation of a protein is determined solely by its amino acid sequence. Chaperones catalyze protein folding without being a part of the folded protein.
The...
Regulation of the Unfolded Protein Response01:31

Regulation of the Unfolded Protein Response

Inositol-requiring kinase one or IRE1 is the most conserved eukaryotic unfolded protein response (UPR) receptor. It is a type I transmembrane protein kinase receptor with a distinctive site-specific RNase activity. As the binding mechanics of the misfolded proteins with the N-terminal domain of IRE-1 are unclear, three binding models — direct, indirect, and allosteric -- are proposed for receptor activation. Nevertheless, it is known that once a misfolded protein associates with IRE1, it...