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 Experiment Videos

Eukaryotic initiation factor 2alpha kinase and phosphatase activity during postischemic brain reperfusion.

D J DeGracia1, S Adamczyk, A J Folbe

  • 1Department of Emergency Medicine, Wayne State University School of Medicine, Detroit, Michigan, 48201, USA.

Experimental Neurology
|March 11, 1999
PubMed
Summary

Related Concept Videos

You might also read

Related Articles

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

Sort by
Same author

Association of hyperglycaemia with hospital mortality in nondiabetic COVID-19 patients: A cohort study.

Diabetes & metabolism·2021
Same author

Transition-transversion encoding and genetic relationship metric in ReliefF feature selection improves pathway enrichment in GWAS.

BioData mining·2018
Same author

An interaction quantitative trait loci tool implicates epistatic functional variants in an apoptosis pathway in smallpox vaccine eQTL data.

Genes and immunity·2016
Same author

Epistasis network centrality analysis yields pathway replication across two GWAS cohorts for bipolar disorder.

Translational psychiatry·2012
Same author

Kinetic and thermodynamic acidity of hydrido transition-metal complexes. 3. Thermodynamic acidity of common mononuclear carbonyl hydrides.

Journal of the American Chemical Society·2011
Same author

Looking beyond borders: integrating best practices in benefit-risk analysis into the field of food and nutrition.

Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association·2011

Reperfusion after brain ischemia increases phosphorylated eukaryotic initiation factor 2 alpha (eIF2alpha(P)). This study found no evidence of PKR activation or altered kinase/phosphatase activity, suggesting regulation of eIF2alpha availability to kinases.

Area of Science:

  • Neuroscience
  • Molecular Biology
  • Biochemistry

Background:

  • Ischemic brain injury involves impaired protein synthesis.
  • Phosphorylation of eukaryotic initiation factor 2 alpha (eIF2alpha) is linked to this inhibition.
  • The specific mechanisms driving eIF2alpha phosphorylation during reperfusion are not fully understood.

Purpose of the Study:

  • To investigate the activity of eIF2alpha kinase and phosphatase during global brain ischemia and reperfusion in rats.
  • To determine the role of PKR (protein kinase R) in eIF2alpha phosphorylation during reperfusion using knockout mice.
  • To elucidate the molecular mechanisms underlying reperfusion-induced eIF2alpha phosphorylation.

Main Methods:

  • Measurement of eIF2alpha kinase and eIF2alpha(P) phosphatase activity in rat brain homogenates after varying durations of ischemia and reperfusion.

Related Experiment Videos

  • Analysis of eIF2alpha phosphorylation levels in wild-type and PKR knockout mice subjected to ischemia and reperfusion.
  • Quantification of cytosolic eIF2alpha(P) and assessment of dephosphorylation rates.

    • Main Results:

    • Cytosolic eIF2alpha(P) increased 18-23 fold in rats after 5 and 90 minutes of reperfusion.
    • eIF2alpha kinase activity decreased by 85% during early reperfusion (5 min), while phosphatase activity remained unchanged.
    • PKR knockout mice showed identical increases in eIF2alpha(P) compared to wild-type mice, indicating PKR is not essential for this phosphorylation.
    • Total eIF2alpha levels were consistent across all experimental groups.

    Conclusions:

    • Reperfusion-induced eIF2alpha phosphorylation is not mediated by PKR activation.
    • The findings contradict hypotheses involving a general increase in eIF2alpha kinase activity or a loss of phosphatase activity.
    • The mechanism likely involves altered availability of eIF2alpha to kinases, rather than changes in kinase/phosphatase activity levels.