Cytoplasmic localization of the mitogen-activated protein kinase activator MEK

The mitogen-activated protein kinase (MAPK) or extracellular signal-regulated kinase (ERK) is phosphorylated and activated by an upstream activator kinase, MEK (MAPK or ERK kinase), in response to mitogenic growth factors. ERKs translocate into the nucleus upon mitogen stimulation, suggesting that t...

Full description

Saved in:
Bibliographic Details
Published in:The Journal of biological chemistry 1994-08, Vol.269 (31), p.19947-19952
Main Authors: Zheng, C F, Guan, K L
Format: Article
Language:English
Subjects:
3T3 Cells
Analytical, structural and metabolic biochemistry
Animals
Base Sequence
Biological and medical sciences
Cell physiology
Cells, Cultured
Cytoplasm - metabolism
DNA Primers
Enzyme Activation
Enzymes and enzyme inhibitors
Fluorescent Antibody Technique
Fundamental and applied biological sciences. Psychology
HeLa Cells
Humans
MAP Kinase Kinase 1
Mice
Mitogen-Activated Protein Kinase 1
Mitogen-Activated Protein Kinase Kinases
Mitogens - pharmacology
Molecular and cellular biology
Molecular Sequence Data
Phosphorylation
Protein-Serine-Threonine Kinases - metabolism
Protein-Tyrosine Kinases - metabolism
Signal transduction
Subcellular Fractions - enzymology
Transferases
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The mitogen-activated protein kinase (MAPK) or extracellular signal-regulated kinase (ERK) is phosphorylated and activated by an upstream activator kinase, MEK (MAPK or ERK kinase), in response to mitogenic growth factors. ERKs translocate into the nucleus upon mitogen stimulation, suggesting that the subcellular redistribution of ERK may play a critical role in signal transfer from cytoplasm to the nucleus. We demonstrated in this report that MEK was exclusively localized in cytoplasm in several cell lines, including Swiss 3T3, HeLa, COS, and PC12. Immunofluorescence analysis of both native and transiently expressed MEK with a MEK-specific antibody revealed that both MEK1 and MEK2 were localized only in the cytoplasm. The cytoplasmic localization of MEK was further supported by subcellular fractionations as well as detergent permeabilization experiments. In contrast to ERK, mitogen stimulation did not cause any nuclear accumulation of MEK. These data suggest that ERK is phosphorylated and activated in the cytoplasm. The activated ERK could subsequently translocate into the nucleus and phosphorylate its nuclear substrates.
ISSN:0021-9258
1083-351X
DOI:10.1016/s0021-9258(17)32112-9