Human and bovine granulocyte chemotactic protein-2: complete amino acid sequence and functional characterization as chemokines.
Tumor cells are capable of simultaneously producing a number of related inflammatory peptides, now classified as chemokines. We have isolated a new human granulocyte chemotactic protein (GCP-2), coproduced with interleukin-8 (GCP-1/IL-8) by osteosarcoma cells. Furthermore, the bovine homologue of human GCP-2 was purified from kidney tumor cells using the same isolation procedure. Both chemokines occur in at least four NH2-terminally truncated forms. These 5-6 kDa proteins do not differ in potency and efficacy as granulocyte chemotactic factors using a standard in vitro migration assay. The complete primary structures of human and bovine GCP-2 were disclosed by sequencing peptide fragments derived from the natural proteins. On the basis of the conservation of four cysteine residues, the two molecules are to be classified within the C-X-C chemokine family, including IL-8. Human and bovine GCP-2 are 67% similar at the amino acid level. Their sequences show only weak similarity with that of IL-8, and human GCP-2 does not cross-react in a radioimmunoassay for IL-8. Human and bovine GCP-2 are specific granulocyte chemotactic factors in that they do not attract human monocytes. Bovine GCP-2 is not species specific since it is at least as active as human GCP-2 on human granulocytes. Both chemokines can also activate postreceptor mechanisms leading to release of gelatinase B by granulocytes. This is indicative for a possible role in inflammation and tumor cell invasion.
Proost
P
P
Rega Institute, University of Leuven, Belgium.
Wuyts
A
A
Conings
R
R
Lenaerts
J P
JP
Billiau
A
A
Opdenakker
G
G
Van Damme
J
J
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002460:Cell Line; D054427:Chemokine CXCL6; D019743:Chemokines, CXC; D002634:Chemotaxis, Leukocyte; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D016207:Cytokines / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D006098:Granulocytes / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D016209:Interleukin-8 / Q000096:biosynthesis; D008969:Molecular Sequence Data; D009000:Monocytes / Q000187:drug effects / Q000502:physiology*; D012516:Osteosarcoma / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014407:Tumor Cells, Cultured
C515503:CXCL6 protein, human; D054427:Chemokine CXCL6; D019743:Chemokines, CXC; D016207:Cytokines; D016209:Interleukin-8