RRC ID 38921
著者 Murakami M, Nakatani Y, Kudo I.
タイトル Type II secretory phospholipase A2 associated with cell surfaces via C-terminal heparin-binding lysine residues augments stimulus-initiated delayed prostaglandin generation.
ジャーナル J Biol Chem
Abstract Type II secretory phospholipase A2 (sPLA2) has been shown to be induced by a variety of proinflammatory stimuli and, therefore, has been implicated in the inflammatory process. In order to determine whether association of sPLA2 with cell surfaces via heparan sulfate proteoglycan is important for its effects on cellular functions, we have identified the critical domain in sPLA2 for heparin and cell surface binding and examined its role in cellular prostaglandin (PG) biosynthesis. Replacement of several conserved Lys residues in the C-terminal region of mouse and rat sPLA2s by Glu resulted in a marked reduction of their capacities to bind to heparin and mammalian cell surfaces without affecting their enzymatic activities toward dispersed phospholipid as a substrate. CHO cells stably transfected with wild-type sPLA2 released about twice as much arachidonic acid (AA) during culture for 10 h with fetal calf serum and interleukin-1beta than cells transfected with vector alone, whereas the ability to enhance AA release was impaired in sPLA2 mutants incapable of binding to cell surfaces. AA released by wild-type sPLA2-transfected CHO cells was metabolized to prostaglandin E2 via prostaglandin endoperoxide H synthase (PGHS)-2 after IL-1beta stimulation, revealing a particular functional linkage of sPLA2 to PGHS-2. In contrast, A23187-initiated immediate AA release over 30 min was not affected by sPLA2 overexpression. Taken together, these results suggest that sPLA2 expressed endogenously and anchored on cell surfaces via its C-terminal heparin-binding domain is involved in the PGHS-2-dependent delayed PG biosynthesis initiated by growth factors and cytokines during long term culture.
巻・号 271(47)
ページ 30041-51
公開日 1996-11-22
DOI 10.1074/jbc.271.47.30041
PII S0021-9258(19)79245-X
PMID 8939951
MeSH Amino Acid Sequence Animals CHO Cells Cell Membrane / enzymology Cricetinae Cyclooxygenase 2 Heparin / metabolism* Lysine / metabolism* Mice Molecular Sequence Data Mutagenesis, Site-Directed Phospholipases A / genetics Phospholipases A / metabolism* Phospholipases A2 Prostaglandin-Endoperoxide Synthases / metabolism Prostaglandins / biosynthesis* Protein Binding Rats Sequence Homology, Amino Acid
IF 4.238
引用数 118
WOS 分野 BIOCHEMISTRY & MOLECULAR BIOLOGY
リソース情報
ヒト・動物細胞 COS-7(RCB0539) CHO-K1(RCB0285) MC3T3-E1(RCB1126)