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The involvement of Gab1 and PI 3‐kinase in β1 integrin signaling in keratinocytes
Author(s) -
Kuwano Yoshihiro,
Fujimoto Manabu,
Watanabe Rei,
Ishiura Nobuko,
Nakashima Hiroko,
Okochi Hitoshi,
Tamaki Kunihiko
Publication year - 2008
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/fasebj.22.1_supplement.1122.13
Subject(s) - integrin , microbiology and biotechnology , stem cell , integrin, beta 6 , biology , chemistry , cell , biochemistry
The control of the stem cell compartment in epidermis are closely linked to the regulation of keratinocyte proliferation and differentiation. β1 integrins are expressed 2‐fold higher by stem cells than transit‐amplifying cells and are considered as an epidermal stem cell marker. Signaling from these β1 integrins is critical for the regulation of the epidermal stem cell compartment. To clarify the functional relevance of this differential expression of β1 integrins, we established HaCaT cells expressing high β1 integrins by repeated flow cytometric sorting of the cells with high β1 integrin expression. In these obtained cells expressing β1 integrins by 5‐fold, MAPK activation was markedly increased. Regarding the upstream of MAPK, Gab1 phosphorylation was also higher with high β1 integrin expression, while She phosphorylation was not altered. In addition, enhanced phosphatidylinositol 3‐kinase activation was also observed. These observations suggest that Gab1 and phosphatidylinositol 3‐kinase play pivotal roles in the β1 integrin‐mediated regulation of the epidermal stem cell compartment.