The Chemokine receptor CXCR4 is a 352 amino acid rhodopsin-like GPCR and selectively binds the CXC chemokine Stromal Cell-Derived Factor 1 (SDF-1) also known as CXCL12. Classically, two alternatively spliced isoforms of SDF have been identified. SDF-1Alpha is an 89 amino acid protein that is the predominantly expressed form of SDF-1 while SDF-1Beta contains a four amino acid extension at the carboxyl terminus. Recently, an additional four splice variants that contain 30 (SDF-1Gamma), 31 (SDF-1Delta), 1 (SDF-1Epsilon), and 51 (SDF-1phi) amino acid extensions at the carboxyl terminus compared to SDF-1Alpha have been identified (Ref.1).
CXCL12 is the sole ligand for the chemokine receptor CXCR4.This receptor has [...]