Related Experiment Video
Updated: Jul 20, 2026

Assaying Protein Kinase Activity with Radiolabeled ATP
Published on: May 26, 2017
Beta-arrestin 2: a receptor-regulated MAPK scaffold for the activation of JNK3
P H McDonald1, C W Chow, W E Miller
1Howard Hughes Medical Institute and Department of Medicine, Duke University Medical Center, Box 3821, Durham, NC 27710, USA.
Abstract:
beta-Arrestins, originally discovered in the context of heterotrimeric guanine nucleotide binding protein-coupled receptor (GPCR) desensitization, also function in internalization and signaling of these receptors. We identified c-Jun amino-terminal kinase 3 (JNK3) as a binding partner of beta-arrestin 2 using a yeast two-hybrid screen and by coimmunoprecipitation from mouse brain extracts or cotransfected COS-7 cells. The upstream JNK activators apoptosis signal-regulating kinase 1 (ASK1) and mitogen-activated protein kinase (MAPK) kinase 4 were also found in complex with beta-arrestin 2. Cellular transfection of beta-arrestin 2 caused cytosolic retention of JNK3 and enhanced JNK3 phosphorylation stimulated by ASK1. Moreover, stimulation of the angiotensin II type 1A receptor activated JNK3 and triggered the colocalization of beta-arrestin 2 and active JNK3 to intracellular vesicles. Thus, beta-arrestin 2 acts as a scaffold protein, which brings the spatial distribution and activity of this MAPK module under the control of a GPCR.
Related Concept Videos
Microtubule Associated Proteins (MAPs)
MAPK Signaling Cascades
The JAK-STAT Signaling Pathway
PI3K/mTOR/AKT Signaling Pathway
cAMP-dependent Protein Kinase Pathways
Calmodulin-dependent Signaling
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...

