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Attenuation of EGF Signaling in Senescent Cells by Caveolin
Author(s) -
Park WoongYang,
Cho KyungA,
Park JeongSoo,
Kim DeokIn,
Park Sang Chul
Publication year - 2001
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1111/j.1749-6632.2001.tb05638.x
Subject(s) - microbiology and biotechnology , caveolin 1 , receptor , stimulation , mapk/erk pathway , epidermal growth factor , signal transduction , kinase , chemistry , cell signaling , phosphorylation , gene isoform , biology , biochemistry , endocrinology , gene
A bstract : One of the characteristics of senescent cells is unresponsiveness to external stimuli like EGF. Although they have a normal level of receptors and downstream signaling molecules, EGF cannot induce the activation of Erk kinases and DNA synthesis in senescent cells as much as in young cells. Caveolin proteins directly interact with signaling molecules including EGF receptor and suppress the activation of EGFR upon EGF stimulation. We found that Erk activation after EGF stimulation in senescent human diploid fibroblasts was down‐regulated. Those senescent cells showed an increased level of three isoforms of caveolin proteins. This change seems to lie in transcriptional control in senescent cells. We also demonstrated up‐regulated caveolin proteins were co‐localized with EGFR proteins in detergent‐insoluble fractions. From these results, we suggest that the up‐regulated expression of caveolin might explain the unresponsiveness of senescent fibroblasts to EGF stimulation.