Platelet-derived growth factor-BB phosphorylates heat shock protein 27 in cardiac myocytes.
It is recognized that heat shock protein 27 (HSP27) is highly expressed in heart. In the present study, we investigated whether platelet-derived growth factor (PDGF) phosphorylates HSP27 in mouse myocytes, and the mechanism underlying the HSP27 phosphorylation. Administration of PDGF-BB induced the phosphorylation of HSP27 at Ser-15 and -85 in mouse cardiac muscle in vivo. In primary cultured myocytes, PDGF-BB time dependently phosphorylated HSP27 at Ser-15 and -85. PDGF-BB stimulated the phosphorylation of p44/p42 mitogen-activated protein (MAP) kinase, p38 MAP kinase, and stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) among the MAP kinase superfamily. SB203580, a specific inhibitor of p38 MAP kinase, reduced the PDGF-BB-stimulated phosphorylation of HSP27 at both Ser-15 and -85, and phosphorylation of p38 MAP kinase. However, PD98059, a specific inhibitor of MEK, or SP600125, a specific inhibitor of SAPK/JNK, failed to affect the HSP27 phosphorylation. These results strongly suggest that PDGF-BB phosphorylates HSP27 at Ser-15 and -85 via p38 MAP kinase in cardiac myocytes.
Takenaka
Motoki
M
Department of Pharmacology, Gifu University School of Medicine, Gifu 500-8705, Japan.
Matsuno
Hiroyuki
H
Ishisaki
Akira
A
Nakajima
Keiichi
K
Hirade
Kouseki
K
Takei
Mariko
M
Yasuda
Eisuke
E
Akamatsu
Shigeru
S
Yoshimi
Naoki
N
Kato
Kanefusa
K
Kozawa
Osamu
O
D000818:Animals; D000077214:Becaplermin; D018929:Cell Culture Techniques; D002478:Cells, Cultured; D006360:Heat-Shock Proteins / Q000378:metabolism*; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000378:metabolism*; D010766:Phosphorylation; D010982:Platelet-Derived Growth Factor / Q000378:metabolism*; D020574:Proto-Oncogene Proteins c-sis; D048051:p38 Mitogen-Activated Protein Kinases
D006360:Heat-Shock Proteins; D010982:Platelet-Derived Growth Factor; D020574:Proto-Oncogene Proteins c-sis; D000077214:Becaplermin; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases