Cytokine-induced neutrophil chemoattractant 1 (CINC-1) was originally purified from media conditioned by IL-1 beta stimulated rat kidney epithelioid cells (NRK-52E). On the basis of its protein and DNA sequences, CINC-1 is a member of the alpha (CXC) subfamily of chemokines. Three additional rat CXC chemokines (CINC-2 alpha, CINC-2 beta, CINC-3/MIP-2), sharing approximately 63-67% amino acid sequence identity with CINC-1, have been identified. The protein sequence of rat CINC-1 is also 68%, 71%, and 69% identical to that of human GRO-alpha, GRO-beta, and GRO-gamma, respectively. Based on their sequence homology, it has been suggested that CINCs are the rat counterpart of human GROs.
Rat CINC-1 cDNA encodes a 96 amino acid residue precursor protein from which the amino-terminal 24 amino acid residues are cleaved to generate the mature CINC-1. Similar to other alpha chemokines, rat CINCs are potent neutrophil attractants and activators and have been shown to play an important role in the infiltration of neutrophils into inflammatory sites in rats.
