Mitogen-activated protein kinases and ribosomal S6 protein kinases are involved in signaling pathways shared by interleukin-11, interleukin-6, leukemia inhibitory factor, and oncostatin M in mouse 3T3-L1 cells.

T Yin,Y.C Yang

doi:10.1016/s0021-9258(17)41921-1

Abstract

The mechanisms of signaling pathways shared by interleukin (IL)-11, IL-6, leukemia inhibitory factor (LIF), and oncostatin M (ONC) remain elusive. We report here that treatment of 3T3-L1 cells with IL-11, IL-6, LIF, and ONC induces overlapping but distinct patterns of tyrosine phosphorylation and activates indistinguishable primary response genes. We further demonstrate for the first time that IL-11, IL-6, LIF, and ONC can trigger the activation of mitogen-activated protein kinases and the 85-92-kDa ribosomal S6 protein kinase (pp90rsk). In addition, our data also show that preincubation of cells with a tyrosine kinase inhibitor herbimycin A, but not with a serine/threonine kinase inhibitor H7, blocks activation of mitogen-activated protein kinases and pp90rsk. Interestingly, H7, but not herbimycin A, inhibits pp90rsk activity in the in vitro kinase assays. These results suggest that pp90rsk is one of the potential candidates for the H7-sensitive protein kinase(s), which is critical for the activation of primary response genes by these cytokines.

Highlights

The mechanisms of signaling pathways sharedby in- various types of cells with different effects, and others may terleukin (IL)-11,IL-6, leukemia inhibitory factor(LIE’), exert the same or similar functions on a given cell type
These results suggest that pp9OrSkis one of the H7-sensitive protein kinases critical for IL-11, IL-6, LIF, or ONC to induce the expression of primary response genes in 3T3-Llcells
3T3-Ll Preadipocytes--To understand whether IL-11,IL-6, Immunoblotting with Anti-phosphotyrosine, Anti-MAP Kinase,and LIF, and ONC signaling pathways are initiated by the activa

Summary

Introduction

The mechanisms of signaling pathways sharedby in- various types of cells with different effects, and others may terleukin (IL)-11,IL-6, leukemia inhibitory factor(LIE’), exert the same or similar functions on a given cell type. LIF,-, and ONC-mediated signaling pathways have not been identified, it is important to examine whether some of the tyrosine-phosphorylated proteins may have intrinsic kinase activities.

Results

Conclusion