Figure 1

Schematic representation of the four chemokine families. Chemokine families are structurally related peptides possessing a pattern of conserved cysteine residues near the amino-terminal (-NH₂) domain. The position of the cysteine residues is the basis for the classification into four families. The -CXC-, or alpha chemokine family, has one amino acid (X) separating two of four conserved cysteine residues. The -CC-, or beta family of chemokines has two adjacent cysteine residues. The -C-chemokine, lymphotactin, has only one conserved cysteine residue. The -CX₃C-chemokine, fractalkine, has three amino acids separating two of four cysteines. Regions of chemokine-receptor interaction are also depicted.