TY - JOUR
T1 - Ultraviolet B-mediated phosphorylation of the small heat shock protein HSP27 in human keratinocytes
AU - Wong, Jon W.
AU - Shi, Biao
AU - Farboud, Behnom
AU - McClaren, Marla
AU - Shibamoto, Takayuki
AU - Cross, Carroll E
AU - Isseroff, Roslyn Rivkah
PY - 2000
Y1 - 2000
N2 - Exposure of human keratinocytes to environmental stress is known to induce changes in the expression, phosphorylation, and subcellular relocalization of the 27 kDa heat shock protein. This study demonstrates that ultraviolet B (280-320 nM) irradiation with physiologic doses induces a dose-dependent phosphorylation of 27kDa heat shock protein, generating the more acidic 27 kDa heat shock protein B, C, and D isoforms. Ultraviolet B also induces perinuclear cytoplasmic relocation and nuclear translocation of 27 kDa heat shock protein and caused aggregation of cytoplasmic actin filaments into a broad perinuclear distribution. The ultraviolet B-induced phosphorylation is reversible, returning to baseline levels 4 h after exposure, and this coincides with the reversal of ultraviolet B-induced actin reorganization. The ultraviolet B-induced phosphorylation is not affected by the protein kinase C inhibitor, GF 109203X, is partially inhibited by epidermal growth factor receptor tyrosine kinase inhibitor. PD 153035, and is substantially inhibited by the specific p38 mitogen-activated protein kinase inhibitor, SB 203580. In addition, pretreatment of cells with the anti-oxidant N-acetyl cysteine partially inhibits ultraviolet B-and oxidant-induced 27 kDa heat shock protein phosphorylation. The p38 mitogen-activated protein kinase cascade is thus the major transduction pathway for ultraviolet B-induced 27 kDa heat shock protein phosphorylation, and reactive oxygen species generated in response to ultraviolet B also contribute to this phosphorylation. As 27 kDa heat shock protein phosphorylation and relocalization has been associated with increased cell survival after environmental insult, our data suggest that ultraviolet B, in addition to initiating recognized cytotoxic events in keratinocytes, also initiates a signaling pathway that may provide cellular protection against this ubiquitous environmental insult.
AB - Exposure of human keratinocytes to environmental stress is known to induce changes in the expression, phosphorylation, and subcellular relocalization of the 27 kDa heat shock protein. This study demonstrates that ultraviolet B (280-320 nM) irradiation with physiologic doses induces a dose-dependent phosphorylation of 27kDa heat shock protein, generating the more acidic 27 kDa heat shock protein B, C, and D isoforms. Ultraviolet B also induces perinuclear cytoplasmic relocation and nuclear translocation of 27 kDa heat shock protein and caused aggregation of cytoplasmic actin filaments into a broad perinuclear distribution. The ultraviolet B-induced phosphorylation is reversible, returning to baseline levels 4 h after exposure, and this coincides with the reversal of ultraviolet B-induced actin reorganization. The ultraviolet B-induced phosphorylation is not affected by the protein kinase C inhibitor, GF 109203X, is partially inhibited by epidermal growth factor receptor tyrosine kinase inhibitor. PD 153035, and is substantially inhibited by the specific p38 mitogen-activated protein kinase inhibitor, SB 203580. In addition, pretreatment of cells with the anti-oxidant N-acetyl cysteine partially inhibits ultraviolet B-and oxidant-induced 27 kDa heat shock protein phosphorylation. The p38 mitogen-activated protein kinase cascade is thus the major transduction pathway for ultraviolet B-induced 27 kDa heat shock protein phosphorylation, and reactive oxygen species generated in response to ultraviolet B also contribute to this phosphorylation. As 27 kDa heat shock protein phosphorylation and relocalization has been associated with increased cell survival after environmental insult, our data suggest that ultraviolet B, in addition to initiating recognized cytotoxic events in keratinocytes, also initiates a signaling pathway that may provide cellular protection against this ubiquitous environmental insult.
KW - 27kDa heat shock protein translocation
KW - Actin filaments
KW - Oxidative stress
KW - P38 MAP kinase
KW - Signal transduction
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U2 - 10.1046/j.1523-1747.2000.00077.x
DO - 10.1046/j.1523-1747.2000.00077.x
M3 - Article
C2 - 10951279
AN - SCOPUS:0033828469
VL - 115
SP - 427
EP - 434
JO - Journal of Investigative Dermatology
JF - Journal of Investigative Dermatology
SN - 0022-202X
IS - 3
ER -