Related Experiment Video
Updated: Feb 17, 2026

Studying RNA Interactors of Protein Kinase RNA-Activated during the Mammalian Cell Cycle
Published on: March 5, 2019
Stimulation of c-Rel transcriptional activity by PKA catalytic subunit beta
Shih-Hung Yu1, Wei-Chung Chiang, Hsiu-Ming Shih
1Institute of Biochemistry, National Yang-Ming University, Taipei 112, Taiwan.
Abstract:
Nuclear factor kappaB (NF-kappaB) is a eukaryotic transcription factor which responds to different extracellular signals. It is involved in immune response, inflammation, and cell proliferation. Increased expression of c-Rel (or its viral homolog v-Rel), one component of the NF-kappaB factors, induces tumorigenesis in different systems. The activity of NF-kappaB can be regulated by protein kinase A (PKA) in a cAMP-independent manner. Our previous results showed that c-MYC induces the activity of PKA by inducing the transcription of the gene encoding the PKA catalytic subunit beta (PKA-Cbeta). Constitutive expression of PKA-Cbeta in Rat1a cells induces their transformation. Here we show that CREB is unlikely to be a phosphorylation target of PKA-Cbeta as characterized by different cell lines. Electrophoretic mobility shift assays showed that c-Rel is present as a significant component of the NF-kappaB factors in c-MYC overexpressing status. The transcriptional activity of c-Rel was significantly stimulated by PKA-Cbeta. Coactivators p300/CBP are at least partially responsible for the enhanced activation mediated by c-Rel and PKA-Cbeta. Interaction between c-Rel and PKA-Cbeta was demonstrated using coimmunoprecipitation assays. Immunoprecipitation-in vitro phosphorylation assays showed the direct phosphorylation of c-Rel by PKA-Cbeta. These results indicate that c-Rel is a reasonable phosphorylation target of PKA-Cbeta, and that the transcriptional activity of c-Rel is stimulated by PKA-Cbeta possibly through the interaction with p300/CBP.
Related Concept Videos
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,...
MAPK Signaling Cascades
Cell Specific Gene Expression
RNA Polymerase II Accessory Proteins
GPCRs Regulate Adenylyl Cylase Activity

