Activation of the MKK4-JNK pathway during erythroid differentiation of K562 cells is inhibited by the heat shock factor 2-beta isoform

A1 Journal article (refereed)

Internal Authors/Editors

Publication Details

List of Authors: Hietakangas, Elo, Rosenström, Coffey, Kyriakis, Eriksson, Sistonen
Publication year: 2001
Journal: FEBS Letters
Journal acronym: FEBS Lett
Volume number: 505
Issue number: 1
Start page: 168
End page: 172
ISSN: 0014-5793
eISSN: 1873-3468


In this study we report the activation of c-Jun N-terminal kinase (JNK) in human K562 erythroleukemia cells undergoing hemin-mediated erythroid differentiation, which occurs concomitantly with activation of heat shock factor 2 (HSF2) and leads to a simultaneous in vivo phosphorylation of c-Jun. The activation of JNK occurs through activation of mitogen-activated protein kinase kinase (MKK) 4 and not by activation of MKK7 or inhibition of JNK-directed phosphatases. We have previously shown that overexpression of the HSF2-beta isoform inhibits the activation of HSF2 upon hemin-induced erythroid differentiation. Here we demonstrate that HSF2-beta overexpression blocks the hemin-induced activation of the MKK4-JNK pathway, suggesting an erythroid lineage-specific JNK activation likely to be regulated by HSF2.

Last updated on 2020-03-08 at 05:18