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Krüppel ‐like factor 5 activates MEK/ERK signaling via EGFR in primary squamous epithelial cells
Author(s) -
Yang Yizeng,
Goldstein Bree G.,
Nakagawa Hiroshi,
Katz Jonathan P.
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fj.06-6694com
Subject(s) - mapk/erk pathway , epidermal growth factor receptor , microbiology and biotechnology , mek inhibitor , cancer research , cell growth , phosphorylation , epidermal growth factor , chromatin immunoprecipitation , signal transduction , chemistry , biology , receptor , promoter , biochemistry , gene expression , gene
Rapid cell proliferation is a hallmark of transit amplifying cells, but the mechanisms of this localized proliferation are not well understood. The Krüppel ‐like factor family member Klf5 (IKLF; BTEB2) promotes cell proliferation and is highly expressed in squamous epithelia, in regions of active proliferation. Here, using mouse primary esophageal keratinocytes as a model, we identify a critical role for Klf5 in regulating squamous epithelial proliferation via the epidermal growth factor receptor (EGFR), which, like Klf5, is localized to basal cells in squamous epithelia. We show that Klf5 increases proliferation, transcriptionally up‐regulates EGFR , and activates MEK/ERK signaling, as indicated by increased phosphorylation of MEK and ERK. By chromatin immunoprecipitation, we demonstrate that Klf5 binds directly to the 5′ regulatory region of EGFR . In addition, we show that regulation of proliferation by Klf5 is dependent on EGFR and MEK/ ERK signaling, as the proliferative response to Klf5 is blocked by pharmacologic inhibition of EGFR or MEK. Inhibition of EGFR or MEK also decreases Klf5 expression. Thus, Klf5 regulates MEK/ERK signaling via EGFR and is also downstream of MAPK signaling, providing a novel mechanism for signal amplification or suppression and control of proliferation in basal cells.—Yang, Y., Goldstein, B. G., Nakagawa, H., Katz, J. P. Krüppel‐like factor 5 activates MEK/ERK signaling via EGFR in primary squamous epithelial cells FASEB J. 21, 543–550 (2007)