Publication
Title
Role of endocytosis in the activation of the extracellular signal-regulated kinase cascade by sequestering and nonsequestering G protein-coupled receptors
Author
Abstract
Acting through a number of distinct pathways, many G protein-coupled receptors (GPCRs) activate the extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) cascade. Recently, it has been shown that in some cases, clathrin-mediated endocytosis is required for GPCR activation of the ERK/MAPK cascade, whereas in others it is not. Accordingly, we compared ERK activation mediated by a GPCR that does not undergo agonist-stimulated endocytosis, the alpha(2A) adrenergic receptor (alpha(2A) AR), with ERK activation mediated by the beta(2) adrenergic receptor (beta(2) AR), which is endocytosed. Surprisingly, we found that in COS-7 cells, ERK activation by the alpha(2A) AR, like that mediated by both the beta(2) AR and the epidermal growth factor receptor (EGFR), is sensitive to mechanistically distinct inhibitors of clathrin-mediated endocytosis, including monodansylcadaverine. a mutant dynamin I, and a mutant beta-arrestin 1. Moreover, we determined that, as has been shown for many other GPCRs, both alpha(2A) and beta(2) AR-mediated ERK activation involves transactivation of the EGFR, Using confocal immunofluorescence microscopy, we found that stimulation of the beta(2) AR, the alpha(2A) AR, or the EGFR each results in internalization of a green fluorescent protein-tagged EGFR. Although beta(2) AR stimulation leads to redistribution of both the beta(2) AR and EGFR, activation of the alpha(2A) AR leads to redistribution of the EGFR but the alpha(2A) AR remains on the plasma membrane. These findings separate GPCR endocytosis from the requirement for clathrin-mediated endocytosis in EGFR transactivation-mediated ERK activation and suggest that it is the receptor tyrosine kinase or another downstream effector that must engage the endocytic machinery.
Language
English
Source (journal)
Proceedings of the National Academy of Sciences of the United States of America. - Washington, D.C.
Publication
Washington, D.C. : 2000
ISSN
0027-8424 [Print]
1091-6490 [Online]
Volume/pages
97:4(2000), p. 1489-1494
ISI
000085409600038
Full text (Publisher's DOI)
Full text (publisher's version - intranet only)
UAntwerpen
Faculty/Department
[E?say:metaLocaldata.cgzprojectinf]
Publication type
Subject
External links
Web of Science
Record
Identification
Creation 06.01.2015
Last edited 02.08.2017