| First Author | Rousseau S | Year | 2002 |
| Journal | EMBO J | Volume | 21 |
| Issue | 23 | Pages | 6505-14 |
| PubMed ID | 12456657 | Mgi Jnum | J:180488 |
| Mgi Id | MGI:5306322 | Doi | 10.1093/emboj/cdf639 |
| Citation | Rousseau S, et al. (2002) Inhibition of SAPK2a/p38 prevents hnRNP A0 phosphorylation by MAPKAP-K2 and its interaction with cytokine mRNAs. EMBO J 21(23):6505-14 |
| abstractText | Lipopolysaccharide (LPS) stimulates production of inflammatory mediators, partly by stabilizing [interleukin-6 (IL-6), cyclooxygenase 2 (COX-2)] and/or stimulating translation [tumour necrosis factor-alpha (TNF-alpha)] of their mRNAs. Such regulation depends on AU-rich elements (AREs) within the 3'-untranslated regions and is partially suppressed by SB 203580 (which inhibits SAPK2a/p38). The LPS-induced production of TNF-alpha and IL-6 is suppressed in MAPKAP-K2-deficient mice (a kinase activated by SAPK2a/p38). Here, we identify 18 macrophage proteins that bind to AREs and show that hnRNP A0 is a major substrate for MAPKAP-K2 in this fraction. MAPKAP-K2 phosphorylated hnRNP A0 at Ser84 in vitro and this residue became phosphorylated in LPS-stimulated cells. Phosphorylation was prevented by SB 203580 and suppressed in macrophages derived from MAPKAP-K2-deficient mice. The mRNAs encoding TNF-alpha, COX-2 and macrophage inflammatory protein-2 (MIP-2) bound to hnRNP A0 in LPS-stimulated macrophages, an interaction prevented by SB 203580. The LPS-induced stabilization of MIP-2 mRNA and production of MIP-2 protein were abolished when macrophages were incubated with SB 203580 plus PD 184352 (which inhibits the classical MAP kinase cascade). Our data suggest that LPS-induced binding of hnRNP A0 to AREs may contribute to the post-transcriptional regulation of specific mRNAs. |
