Inhibition of the MEK1/ERK pathway reduces arachidonic acid release independently of cPLA2 phosphorylation and translocation.
BMC Biochem
; 3: 30, 2002 Oct 08.
Article
en En
| MEDLINE
| ID: mdl-12370087
ABSTRACT
BACKGROUND:
The 85-kDa cytosolic phospholipase A2 (cPLA2) mediates arachidonic acid (AA) release in MDCK cells. Although calcium and mitogen-activated protein kinases regulate cPLA2, the correlation of cPLA2 translocation and phosphorylation with MAPK activation and AA release is unclear.RESULTS:
MEK1 inhibition by U0126 inhibited AA release in response to ATP and ionomycin. This directly correlated with inhibition of ERK activation but not with phosphorylation of cPLA2 on Ser505, which was only partially inhibited by ERK inhibition. Inhibition of AA release by U0126 was still observed when stoichiometric phosphorylation of cPLA2 on Ser505 was maintained by activating p38 with anisomycin. Translocation kinetics of wild-type cPLA2 and cPLA2 containing S505A or S727A mutations to Golgi were similar in response to ATP and ionomycin and were not affected by U0126.CONCLUSIONS:
These results suggest that the ability of cPLA2 to hydrolyze membrane phospholipid is reduced by inhibition of the MEK1/ERK pathway and that the reduction in activity is independent of cPLA2 phosphorylation and translocation to membrane. The results also demonstrate that cPLA2 mutated at the phosphorylation sites Ser505 and Ser727 translocated with similar kinetic as wild-type cPLA2.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Fosfolipasas A
/
Butadienos
/
Ácido Araquidónico
/
Proteínas Serina-Treonina Quinasas
/
Quinasas de Proteína Quinasa Activadas por Mitógenos
/
Proteínas Quinasas Activadas por Mitógenos
/
Inhibidores Enzimáticos
/
Nitrilos
Límite:
Animals
/
Humans
Idioma:
En
Revista:
BMC Biochem
Asunto de la revista:
BIOQUIMICA
Año:
2002
Tipo del documento:
Article
País de afiliación:
Estados Unidos