Phospholipid Binding: C2 Domain

The N-terminal C2 domain of Synaptotagmin I.

Domain Binding and Function

The C2 domain is a region containing approximately 130 residues that is found in proteins that bind phospholipids in either a calcium-dependent 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 induces a change in electrostatic potential that enhances phospholipid binding. This suggests that the C2 domain functions as an electrostatic switch. In addition, side chains in the calcium binding loops influence the binding of different C2 domains to either neutral or negatively charged phospholipids.

Structure Reference

  1. Sutton, R.B. et al. (1995) Cell 80(6), 929–938.

Examples of Domain Proteins

Phospholipid Binding: C2 Domain

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