Activation by phosphorylation and purification of human c-Jun N-terminal kinase (JNK) isoforms in milligram amounts
c-Jun N-terminal kinases (JNKs) are part of the mitogen-activated protein kinase (MAPK) signaling cascade. They are activated through dual phosphorylation of two residues in the activation loop, a threonine and a tyrosine, by MAP2 kinases (MKK4 and 7) in response to various extracellular stresses su...
Saved in:
Published in | Protein expression and purification Vol. 75; no. 2; pp. 138 - 146 |
---|---|
Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
United States
Elsevier Inc
01.02.2011
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | c-Jun N-terminal kinases (JNKs) are part of the mitogen-activated protein kinase (MAPK) signaling cascade. They are activated through dual phosphorylation of two residues in the activation loop, a threonine and a tyrosine, by MAP2 kinases (MKK4 and 7) in response to various extracellular stresses such as UV or osmotic shock, as well as by cytokines and growth factors. Only small amounts of phosphorylated, active JNKs have previously been produced because of difficulties in expressing these phosphorylated kinases in
Escherichia coli, which lack the appropriate upstream kinases. We have now established a novel activation and purification method that allows for reproducible production of milligram amounts of active, phosphorylated JNKs suitable for a variety of enzymatic, biophysical and structural characterizations. We utilize N-terminally His-tagged MKK4 that is coexpressed in
E. coli with a constitutively active form of MEKK1. This phosphorylated, active His-MKK4 is purified by Ni–NTA chromatography and used to phosphorylate milligram amounts of three different isoforms of human JNKs (JNK1α1, JNK1α2 and JNK2α2) that had separately been expressed and purified from
E. coli in their inactive forms. These
in vitro activated JNKs are phosphorylated on both residues (T183, Y185) in their activation loops and are active towards their substrate, ATF2. |
---|---|
Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1046-5928 1096-0279 |
DOI: | 10.1016/j.pep.2010.08.002 |