Neuronal calcium sensor-1 (NCS-1) is a member of the neuronal calcium sensor family of EF-hand Ca²⁺-binding proteins that triggers different biological processes to regulate signal transduction in neurons and photoreceptor cells. This family of proteins includes 15 members and is primarily expressed in neurons. 

The protein interacts with the G-protein coupled receptor (GPCR) Dopamine D2 receptor (D2R), and the cognate kinases GRK1 and GRK2. NCS-1 responds to changes in intracellular Ca²⁺ concentration and is involved in many important physiological functions including the regulation of neurotransmitter release, synaptic plasticity, learning and memory, neurite growth, and neuronal survival^1,2_.

NCS-1 structure is characterized by 4 helix-loop-helix motifs, called EF-hand motifs able to bind Ca²⁺ ions. These domains are separated by a short loop containing a conserved glycine residue. NCS-1 is targeted to the plasma membrane by an N-terminal myristoylation group through the action of N-miristoyltransferase. Opposite to the EF-motifs is a wide hydrophobic crevice (HC). This area has the ability to interact with various physiological targets^2,3_.

NCS-1 dysfunctions are linked to mental conditions, such as bipolar disorder, schizophrenia and autism²_.