Ligation of the alpha M-2* signaling receptor regulates synthesis of cytosolic phospholipase A(2)

Citation
Uk. Misra et Sv. Pizzo, Ligation of the alpha M-2* signaling receptor regulates synthesis of cytosolic phospholipase A(2), ARCH BIOCH, 386(2), 2001, pp. 227-232
Citations number
51
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biochemistry & Biophysics
Journal title
ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS
ISSN journal
0003-9861 → ACNP
Volume
386
Issue
2
Year of publication
2001
Pages
227 - 232
Database
ISI
SICI code
0003-9861(20010215)386:2<227:LOTAMS>2.0.ZU;2-U
Abstract
We have studied the regulation of cytosolic phospholipase A(2) (cPLA(2)) sy nthesis in macrophages stimulated with receptor-recognized forms of alpha ( 2)-macroglobulin (alpha M-2*). [S-35]methionine-labeled cells were stimulat ed with alpha M-2* and [S-35]cPLA(2) was immunoprecipitated with a monoclon al antibody directed against cPLA(2), The precipitates were electrophoresed , immunoblotted, cPLA(2) detected by Enhanced Chemifluorescence, and its ra dioactivity determined. Stimulation of cells with alpha M-2* caused a two- to threefold increase in cPLA(2) synthesis compared to buffer-treated cells which was consistently maximal at 200 pM of alpha M-2*. Actinomycin D or c ycloheximide treatment of cells drastically reduced alpha M-2*-induced cPLA (2) synthesis. Likewise, inhibition of protein kinase C with chelerythrin, farnesyl transferase with manumycin A, MEK kinase with U0126, Erk1/2 kinase s with PD98059, p38MAPK with SB203580, PI 3-kinase with wortmannin or LY294 002, p(70s6k) with rapamycin, or depletion of [Ca2+](i) with either BAPTA/A M or EGTA drastically reduced alpha M-2* induction of cPLA(2), Inhibition o f NF kappaB activation with BAY11-7182 or PGA(1) also abolished alpha M-2* induction of cPLA(2). We conclude that alpha M-2*-induced cPLA(2) synthesis is controlled by [Ca2+](i) levels, tyrosine kinase activity, the p21(ras)- dependent MAPK and PI 3-kinase downstream signaling pathways, and regulatio n of NF kappaB. (C) 2001 Academic Press.