Anti-CXCR-4 from rabbit, purified by affinity chromatography

C-X-C chemokine receptor type 4 (UniProt: P61073; also known as CXC-R4, CXCR-4, FB22, Fusin, HM89, LCR1, Leukocyte-derived seven transmembrane domain receptor, LESTR, Lipopolysaccharide-associated protein 3, LAP-3, LPS-associated protein 3, NPYRL, Stromal cell-derived factor 1 receptor, SDF-1 receptor, CD184) is encoded by the CXCR4 gene (Gene ID: 7852) in human. CXCR-4 is a receptor for the C-X-C chemokine CXCL12/SDF-1 that transduces a signal by increasing intracellular calcium levels and enhancing MAPK1/MAPK3 activation. CXCR-4 is expressed in numerous tissues and two isoforms have been reported that are generated by alternative splicing. Isoform 1 is the predominant form in all tissues tested. CXCR-4 is rapidly phosphorylated on serine and threonine residues in the C-terminal upon agonist stimulation. Phosphorylation at Ser324 and Ser325 leads to recruitment of ITCH (E3 ubiquitin-protein ligase), ubiquitination and protein degradation. Sulfation on Tyr21 is shown to be essential for efficient binding of CXCL12/SDF-1alpha and it promotes its dimerization. Tyr7 and Tyr12 are sulfated in a sequential manner following complete sulfation of Tyr21. CXCR-4 acts as a co-receptor for human HIV-1 virus isolates (CD4 being the primary receptor) and as a primary receptor for HIV-2 isolates. CXCR-4 can also bind bacterial lipopolysaccharide (LPS) and mediate LPS-induced inflammatory response, including TNF-alpha secretion by monocytes. Mutations in CXCR4 gene cause WHIM syndrome that is characterized by neutropenia, hypogammaglobulinemia and extensive human papillomavirus (HPV) infection.