Ten ERK-related proteins in three distinct classes associate with AP-1 proteins and/or AP-1 DNA.
We have identified seven ERK-related proteins ("ERPs"), including ERK2, that are stably associated in vivo with AP-1 dimers composed of diverse Jun and Fos family proteins. These complexes have kinase activity. We designate them as "class I ERPs." We originally hypothesized that these ERPs associate with DNA along with AP-1 proteins. We devised a DNA affinity chromatography-based analytical assay for DNA binding, the "nucleotide affinity preincubation specificity test recognition" (NAPSTER) assay. In this assay, class I ERPs do not associate with AP-1 DNA. However, several new "class II" ERPs do associate with DNA. p41 and p44 are ERK1/2-related ERPs that lack kinase activity and associate along with AP-1 proteins with AP-1 DNA. Class I ERPs and their associated kinase activity thus appear to bind AP-1 dimers when they are not bound to DNA and then disengage and are replaced by class II ERPs to form higher order complexes when AP-1 dimers bind DNA. p97 is a class III ERP, related to ERK3, that associates with AP-1 DNA without AP-1 proteins. With the exception of ERK2, none of the 10 ERPs appear to be known mitogen-activated protein kinase superfamily members.
Kumar
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NV
Department of Pathology and Laboratory Medicine, Texas A & M University System Health Science Center, College Station, Texas 77843-1114, USA.
Bernstein
L R
LR
D001665:Binding Sites; D002846:Chromatography, Affinity; D004247:DNA / Q000378:metabolism*; D019281:Dimerization; D019073:HT29 Cells; D006801:Humans; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D011233:Precipitin Tests; D011485:Protein Binding; D018808:Transcription Factor AP-1 / Q000235:genetics / Q000378:metabolism*
D018808:Transcription Factor AP-1; D004247:DNA; D020928:Mitogen-Activated Protein Kinases