Calcium binding protein 1 is a protein that in humans is encoded by the CABP1 gene. Calcium-binding protein 1 is a calcium-binding protein discovered in 1999. It has two EF hand motifs and is expressed in neuronal cells in such areas as hippocampus, habenular nucleus of the epithalamus, Purkinje cell layer of the cerebellum, and the amacrine cells and cone bipolar cells of the retina. Calcium-binding protein 1 which is a neuron -specific member of the calmodulin (CaM) superfamily which modulates Ca2+-dependent activity of inositol trisphosphate receptors (InsP3RS). L-CaBP1 is also associated with the cytoskeleton structures. But the S-CaBP1 is situated in or near the plasma membrane. In brain, CaBp1 is found in the cerebral cortex and hippocampus and in the protein, Cabp1 is found in cone bipolar and amacrine cells. We can also express that CaBP1 may regulate Ca2+ dependent activity of InSP3Rs by promoting structural contacts between suppressor and core domains but has no effect on INsP3 binding to the receptor. CaBP1 contains four EF-hands in two separate domains namely, EF1 and Ef2 is contained in N-domain whereas Ef3 and EF4 is contained in c domain to which Ca2+ binds. Calcium-binding protein 1 (CaBP1) is placed in the lumen of the endoplasmic reticulum.it is relocated outside cells during apoptosis and involved in the phagocytosis of apoptotic cells. CaBP1 and CaM. lobes fold independently. CaBP1-CaM chimeras based on exchange of three elements these are N-lobe, C-lobe and inter lobe linker. Expression of CaBP1 helps to block Ca2+-dependent facilitation of P/Q-type Ca2+ current which is markedly reduced facilitation of synaptic transmission. Protein structure Protein that attributes for CABP1 Gene is homodimer. It interacts with ITPR1, ITPR2 and ITPR3 via C-terminus. The binding is calcium dependent and the interaction correlates with calcium concentration. CABP1 also interacts with CACNA1A in the pre and post synaptic membranes via C-terminal calcium binding motif. It also interacts with CACNA1C via C-terminal C and IQ motifs. It interacts with TRPC5 and also interacts with MAP1LC3B via C-terminus and EF-hands 1 and 2 respectively. It interacts with C9orf9. It also interacts NSMF via the central NLF- containing motif region. This interaction occurs in calcium dependent manner after the Synaptic NMDA receptor stimulation and thus this prevents nuclear import of NSMF. Function Calcium binding proteins are an important component of calcium mediated cellular signal transduction. This gene encodes a protein that belongs to a subfamily of calcium binding