Related Experiment Video

Updated: Aug 5, 2026

Spatial and Temporal Analysis of Active ERK in the C. elegans Germline
08:40

Spatial and Temporal Analysis of Active ERK in the C. elegans Germline

Published on: November 29, 2016

Active ERK contributes to protein translation by preventing JNK-dependent inhibition of protein phosphatase 1

Martha M Monick1, Linda S Powers, Thomas J Gross

  • 1University of Iowa Carver College of Medicine, Veterans Administration Medical Center, Iowa City, IA 52242, USA. martha-monick@uiowa.edu

Journal of Immunology (Baltimore, Md. : 1950)
|July 20, 2006
PubMed

Insights

The ERK pathway in human alveolar macrophages promotes cell survival by boosting protein translation. Constitutive ERK activity maintains this process, crucial for immune cell homeostasis in the lungs.

Area of Science:

  • Immunology
  • Cell Biology
  • Molecular Biology

Background:

  • Human alveolar macrophages are key immune cells in the lung with extended lifespans.
  • The ERK MAPK pathway is constitutively active in these cells and linked to their prolonged survival.

Purpose of the Study:

  • To investigate the role of the ERK pathway in regulating protein translation in human alveolar macrophages.
  • To elucidate the molecular mechanisms by which ERK influences cell survival.

Main Methods:

  • Utilized [(35)S]methionine labeling to measure protein translation rates.
  • Investigated the phosphorylation states and activities of ERK, JNK, protein phosphatase 1 (PP1), and eukaryotic initiation factor (eIF) 2alpha.

Main Results:

  • ERK inhibition significantly decreased protein translation rates.
  • Decreased translation resulted from eIF2alpha phosphorylation (inactivation) due to increased JNK activity.
  • ERK activation inhibits JNK, leading to PP1 activation, eIF2alpha dephosphorylation, and translation initiation.

Conclusions:

  • Constitutive ERK activity positively regulates protein translation in human alveolar macrophages through a novel pathway involving JNK, PP1, and eIF2alpha.
  • This ERK-mediated regulation of protein translation contributes to the homeostasis and survival of alveolar macrophages in their unique lung microenvironment.

More Related Videos

Assaying Protein Kinase Activity with Radiolabeled ATP08:05

Assaying Protein Kinase Activity with Radiolabeled ATP

Published on: May 26, 2017

Studying RNA Interactors of Protein Kinase RNA-Activated during the Mammalian Cell Cycle10:05

Studying RNA Interactors of Protein Kinase RNA-Activated during the Mammalian Cell Cycle

Published on: March 5, 2019

Related Concept Videos

Protein Kinases and Phosphatases02:54

Protein Kinases and Phosphatases

Proteins undergo chemical modifications that trigger changes in the charge, structure, and conformation of the proteins. Phosphorylation, acetylation, glycosylation, nitrosylation, ubiquitination, lipidation, methylation, and proteolysis are various protein modifications that regulate protein activity. Such modifications are usually enzyme-driven.
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
The Unfolded Protein Response01:37

The Unfolded Protein Response

The ER is the hub of protein synthesis in a cell. It has robust systems to quality control protein folding and also for degradation of terminally misfolded proteins. Under normal conditions, a small proportion of misfolded proteins that cannot be salvaged need to be transported to the cytoplasm by the ER-associated degradation or ERAD pathways. However, if the ERAD cannot handle the misfolded proteins, the cell activates the unfolded protein response or UPR to adjust the protein folding...
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...
Protein Kinases and Phosphatases02:54

Protein Kinases and Phosphatases

Proteins undergo chemical modifications that trigger changes in the charge, structure, and conformation of the proteins. Phosphorylation, acetylation, glycosylation, nitrosylation, ubiquitination, lipidation, methylation, and proteolysis are various protein modifications that regulate protein activity. Such modifications are usually enzyme-driven.
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Amplifying Signals via Enzymatic Cascade01:22

Amplifying Signals via Enzymatic Cascade

When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze the...
The JAK-STAT Signaling Pathway01:20

The JAK-STAT Signaling Pathway

Several cytokine receptors have tightly bound Janus kinase or JAK proteins attached at their cytosolic tail. Small signaling molecules such as cytokines, growth hormones, or prolactins bind to the cytokine receptors and initiate their dimerization. The dimerization brings the cytosolic JAKs together that trans-phosphorylate and activates each other. The activated JAKs now phosphorylate cytosolic tails of the cytokine receptors, which serve as binding sites for adaptor proteins such as  SH2...