Related Experiment Video
Updated: Feb 6, 2026

Biocytin Recovery and 3D Reconstructions of Filled Hippocampal CA2 Interneurons
Published on: November 20, 2018
The Effect of Ca2+, Lobe-Specificity, and CaMKII on CaM Binding to NaV1.1
Jianing Li1, Zhiyi Yu2, Jianjun Xu3
1Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang 110122, China. Ariene77687@outlook.com.
Abstract:
Calmodulin (CaM) is well known as an activator of calcium/calmodulin-dependent protein kinase II (CaMKII). Voltage-gated sodium channels (VGSCs) are basic signaling molecules in excitable cells and are crucial molecular targets for nervous system agents. However, the way in which Ca2+/CaM/CaMKII cascade modulates NaV1.1 IQ (isoleucine and glutamine) domain of VGSCs remains obscure. In this study, the binding of CaM, its mutants at calcium binding sites (CaM12, CaM34, and CaM1234), and truncated proteins (N-lobe and C-lobe) to NaV1.1 IQ domain were detected by pull-down assay. Our data showed that the binding of Ca2+/CaM to the NaV1.1 IQ was concentration-dependent. ApoCaM (Ca2+-free form of calmodulin) bound to NaV1.1 IQ domain preferentially more than Ca2+/CaM. Additionally, the C-lobe of CaM was the predominant domain involved in apoCaM binding to NaV1.1 IQ domain. By contrast, the N-lobe of CaM was predominant in the binding of Ca2+/CaM to NaV1.1 IQ domain. Moreover, CaMKII-mediated phosphorylation increased the binding of Ca2+/CaM to NaV1.1 IQ domain due to one or several phosphorylation sites in T1909, S1918, and T1934 of NaV1.1 IQ domain. This study provides novel mechanisms for the modulation of NaV1.1 by the Ca2+/CaM/CaMKII axis. For the first time, we uncover the effect of Ca2+, lobe-specificity and CaMKII on CaM binding to NaV1.1.
Related Concept Videos
C4 Pathway and CAM
C4 Pathway
The C4 pathway is used by plants such as...
Lobes of the Cerebrum
Frontal lobe
The frontal lobes, located behind the forehead, are the command center of our brain, controlling personality, intelligence, and voluntary muscle movements....
The Equilibrium Binding Constant and Binding Strength
The Equilibrium Binding Constant and Binding Strength
Ligand Binding Sites
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
Conserved Binding Sites
Binding sites are often located in large pockets, and if their location on a protein’s surface is unknown, it can be predicted using various approaches. The energetic method computationally...

