Related Experiment Video
Updated: Jun 6, 2026

Monitoring Activation of the Antiviral Pattern Recognition Receptors RIG-I And PKR By Limited Protease Digestion and Native PAGE
Published on: July 29, 2014
Phosphorylation of RIG-I by casein kinase II inhibits its antiviral response
Zhiguo Sun1, Hongwei Ren, Yan Liu
1National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100871, China.
Abstract:
RIG-I is an intracellular RNA virus sensor that mediates a signaling pathway that triggers the alpha/beta interferon (IFN-α/β) immune defenses. However, the mechanism for regulation of RIG-I activity remains largely unknown. Here we show that RIG-I activity is regulated by phosphorylation and dephosphorylation in its repressor domain (RD). Threonine at amino acid (aa) 770 and serine at aa 854 to 855 of RIG-I are phosphorylated by casein kinase II (CK2) in the resting state of the cell and dephosphorylated when cells are infected by RNA virus. Mutation at aa position 770 or 854 to 855 of RIG-I renders it constitutively active. Pharmacological inhibition of CK2 enhances virus-induced expression of IFN-β and suppresses virus proliferation, while inhibition of phosphatase reduces virus-induced expression of IFN-β. Overexpression of CK2 suppresses RIG-I-mediated signaling, while silencing of CK2 results in the increased suppression of virus proliferation. Our results reveal a novel mechanism of the regulation of RIG-I activity during RNA virus infection.
Related Concept Videos
Inhibitors of Viral Protein Synthesis
The JAK-STAT Signaling Pathway
PI3K/mTOR/AKT Signaling Pathway
Protein Kinases and Phosphatases
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Protein Kinases and Phosphatases
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
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,...

