Phospholipid Binding: C2 Domain
The N-terminal C2 domain of Synaptotagmin I.
Domain Binding and Function
The C2 domain, a region containing approximately 130 residues, is involved in binding phospholipids in a calcium-dependent manner or calcium-independent manner. C2 domains are found in over 100 different proteins with functions ranging from signal transduction to vesicular trafficking. Calcium binding to the C2 domain of synaptotagmin induces little conformational change in the C2 domain but rather induces a change in electrostatic potential, thereby enhancing phospholipid binding. This suggests that the C2 domain functions as an electrostatic switch. In addition to electrostatic interactions, side chains in the calcium binding loops influence the binding of different C2 domains to either neutral or negatively charged phospholipids.
Structure Reference
- Sutton, R.B. et al. (1995) Cell 80(6), 929–938.
Examples of Domain Proteins
Binding Examples
| C2 Domain Proteins | Binding partners |
|---|---|
| PKCβ Ser/Thr Kinase | Ca2+ and acidic phospholipids |
| Synaptotagmin | Ca2+ and acidic phospholipids |
| Integral membrane protein in synaptic vesicles | Ca2+ and acidic phospholipids |
