Importance of the amino terminus of the interleukin-8 receptor in ligand interactions.
Interleukin-8 (IL-8) and growth regulatory gene/melanoma growth stimulatory activity (GRO/MGSA) are small polypeptide molecules involved in the chemotactic response of certain cell types. Two receptors have been described which interact with IL-8, designated type 1 and type 2. IL-8 binds with high affinity to both receptors, whereas GRO/MGSA and neutrophil-activating peptide-2 demonstrate a high degree of binding only to the type 2 receptor. The two forms of IL-8 receptor are members of the rhodopsin seven-helix membrane-spanning superfamily, and share a high degree of overall homology, although the amino termini are very divergent. By using conserved restriction enzyme sites, a series of chimeric IL-8 receptor molecules were constructed between the type 1 and type 2 receptors and transfected into human 293 kidney epithelial cells. These chimeric molecules altered regions of the receptor presented to the ligand. The ability of the chimeric receptors to bind IL-8 was determined, as well as the ability of IL-8 and GRO/MGSA to inhibit radiolabeled IL-8 binding. The amino terminus of the IL-8 receptors was found to be important for differential binding of GRO/MGSA and IL-8. In addition, a series of peptides was also constructed to further investigate which residues of IL-8 receptor interact with IL-8. These peptides also identified the amino-terminal sequence of the IL-8 receptors as being important in interacting with IL-8.
Gayle
R B
RB
Immunex Research and Development Corporation, Seattle, Washington 98101.
Sleath
P R
PR
Srinivason
S
S
Birks
C W
CW
Weerawarna
K S
KS
Cerretti
D P
DP
Kozlosky
C J
CJ
Nelson
N
N
Vanden Bos
T
T
Beckmann
M P
MP
D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D054360:Chemokine CXCL1; D019743:Chemokines, CXC; D002630:Chemotactic Factors / Q000378:metabolism; D003001:Cloning, Molecular; D006133:Growth Substances / Q000378:metabolism; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D016209:Interleukin-8 / Q000378:metabolism*; D008024:Ligands; D008956:Models, Chemical; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000378:metabolism; D011233:Precipitin Tests; D011817:Rabbits; D011971:Receptors, Immunologic / Q000737:chemistry / Q000378:metabolism*; D023062:Receptors, Interleukin-8A; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
C475829:CXCL1 protein, human; D054360:Chemokine CXCL1; D019743:Chemokines, CXC; D002630:Chemotactic Factors; D006133:Growth Substances; D036341:Intercellular Signaling Peptides and Proteins; D016209:Interleukin-8; D008024:Ligands; D010446:Peptide Fragments; D011971:Receptors, Immunologic; D023062:Receptors, Interleukin-8A; D011993:Recombinant Fusion Proteins