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Extracellular heat shock protein 70 mediates heat stress‐induced epidermal growth factor receptor transactivation in A431 carcinoma cells
Author(s) -
Evdonin Anton L.,
Guzhova Irina V.,
Margulis Boris A.,
Medvedeva Natalia D.
Publication year - 2006
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2006.11.024
Subject(s) - transactivation , epidermal growth factor receptor , hsp70 , heat shock protein , a431 cells , secretion , microbiology and biotechnology , mapk/erk pathway , epidermal growth factor , chemistry , biology , cancer research , signal transduction , receptor , biochemistry , transcription factor , oncogene , cell , gene , cell cycle
The initial steps of heat stress in A431 cells were previously characterized by ligand‐independent EGFR transactivation via an unknown mechanism and concomitant secretion of Hsp70. In this work we demonstrate that the depletion of Hsp70 from the conditioned medium of heated cells abolishes EGFR transactivation indicating that secreted Hsp70 is essential for EGFR transactivation during heat shock. This notion is supported by the findings that purified Hsp70 can induce EGFR transactivation and the activation of EGFR‐dependent signaling pathways. Both heat stress and pure Hsp70 stimulate activation of TLR2/4 and their association with EGFR. These results suggest that the secreted Hsp70 mediates the cross‐communication of TLR and EGFR signaling systems in A431 cells.