Membrane binding of Neuronal Calcium Sensor-1 (NCS1)
Samuel Lemire1, Andreas Jeromin2, Élodie Boisselier1
1CUO-Recherche, Hôpital du Saint-Sacrement, Centre de recherche du CHU de Québec and Département d'ophtalmologie, Faculté de médecine, Université Laval, Québec, Québec, Canada.
Colloids and Surfaces. B, Biointerfaces
|December 27, 2015
Summary
Neuronal Calcium Sensor-1 (NCS1) binding to cell membranes is influenced by calcium levels and lipid composition. Myristoylation appears to play a structural role rather than mediating a calcium-myristoyl switch.
Area of Science:
- Biochemistry
- Molecular Biology
- Cell Biology
Background:
- Neuronal Calcium Sensor-1 (NCS1) is a calcium-binding protein with four EF-hand motifs and N-terminal myristoylation.
- The role of a calcium-myristoyl switch in NCS1's membrane interactions remains debated.
Purpose of the Study:
- To investigate the membrane binding characteristics of NCS1 using a Langmuir lipid monolayer model.
- To elucidate the influence of calcium and myristoylation on NCS1's membrane interactions and conformation.
Main Methods:
- Utilized Langmuir lipid monolayers to mimic cell membranes for protein-lipid interaction studies.
- Calculated binding parameters including maximum insertion pressure and synergy.
- Analyzed membrane binding in the presence and absence of calcium and with myristoylated NCS1.
Main Results:
- NCS1 exhibited enhanced binding to phospholipids with phosphoethanolamine head groups and unsaturated fatty acyl chains.
- Absence of calcium led to significantly altered membrane binding, suggesting stronger association.
- Calcium binding induced a conformational change in NCS1, potentially altering its membrane arrangement.
- Myristoylation had a minimal impact on membrane binding, questioning the calcium-myristoyl switch hypothesis.
Conclusions:
- NCS1's membrane interactions are modulated by calcium-dependent conformational changes and lipid composition.
- The myristoyl group likely serves a structural role in NCS1 folding rather than a direct calcium-myristoyl switch mechanism.
- Findings provide insights into NCS1's biological functions through its membrane association dynamics.
Related Concept Videos
01:16Calmodulin-dependent Signaling
7.0K
Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
7.0K
01:30Ligand-Gated Ion Channel Receptor: Gating Mechanism
4.7K
Ligand-gated ion channels are transmembrane proteins that play a vital role in intercellular communication and functions of the nervous system. They allow the influx of ions across the membrane once the neurotransmitter binds, allowing the subsequent transmission of electrical excitation across the neurons. Other ligand-gated ion channels, like the γ-aminobutyric acid (GABA) receptor, permit anions like chloride into the cells on the binding of the GABA molecule. Their entry into the cell...
4.7K
01:26Fusion of Secretory Vesicles with the Plasma Membrane
19.4K
Proteins and neurotransmitters in secretory vesicles can be released from a cell upon vesicle docking, priming, and fusion with the plasma membrane. Vesicles are docked and primed in preparation for the quick exocytosis of their contents in response to a stimulus. The fusion process is mainly carried out by a SNAP Receptor or SNARE complex, consisting of synaptobrevin, syntaxin-1, and SNAP-25.
In 1993, Jim Rothman proposed that the antiparallel pairing of vesicular and transmembrane SNAREs, or...
In 1993, Jim Rothman proposed that the antiparallel pairing of vesicular and transmembrane SNAREs, or...
19.4K
01:23Catenins
3.3K
Catenins are characterized by multiple binding domains and dynamic structures that allow them to function as linker proteins in cell junction complexes. All catenins, except α-catenin, contain a characteristic protein sequence called the armadillo repeat and are therefore also called armadillo proteins.
Catenins in Cell Junctions
Catenins bind to cell adhesion molecules such as cadherins and link them to different cytoskeletal proteins depending on the type of cell junction. At the...
Catenins in Cell Junctions
Catenins bind to cell adhesion molecules such as cadherins and link them to different cytoskeletal proteins depending on the type of cell junction. At the...
3.3K
01:25Structure of Cadherins
5.2K
The cadherins were one of the first cell adhesion molecules discovered; the term “cadherins” is based on their calcium-dependent adhering properties. The first cadherins discovered on the epithelial, neuronal, and placental cells were named E-cadherin, P-cadherin, and N-cadherin, respectively. These classical cadherins share sequence and structural similarities. Other cadherins, including those involved in cell signaling, are grouped into non-classical cadherins. This...
5.2K
01:26Chemical Synapses
8.4K
Chemical synapses are specialized sites between two neurons or between a neuron and a non-neuronal cell like a muscle, glandular or sensory cell.
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
8.4K