GRO-alpha

CXCL1 (Chemokine (C-X-C motif) ligand 1), also known as GRO alpha, NAP-3 or MGSA, belongs to the sub-family of CXC chemokine, is a polypeptide that is initially isolated from human melanoma cells. CXCL1 is involved in the development of many inflammatory diseases, including the induction of angiogenesis and recruitment of neutrophils. CXCL1 is produced by many cell types, and activates CXCR2 and, at high levels, CXCR1^[1]. CXCL1 also modulates angiogenesis, tumorigenesis, and wound healing^[2].
After translation, the synthesized CXCL1 precursor is 107aa long. A signal peptide is removed from its N-terminus, which shortens the precursor to 73aa. Two other amino acids can also be removed from the C-terminus. In addition, two disulfide bridges are formed from all four cysteine residues in CXCL1After secretion, CXCL1 undergoes further proteolytic processing, which regulates the activity of this chemokine. From the N-terminus, three, four or five amino acids are removed, which produce CXCL1(4-73), CXCL1(5-73), and CXCL1(6-73), respectively. This increases CXCL1 activity 30 times. To date, three CXCL1 receptors have been discovered-CXCR1, CXCR2 and atypical chemokine receptor 1 (ACKR1). Through NF-κB activation, CXCL1 expression is increased by cytokines such as IL-1β, TNF-α and IL-17. CXCL1 can associate into bioactive dimers^[1].