Eotaxin and monocyte chemotactic protein-3 use different modes of action.
Eotaxin selectively binds CC chemokine receptor (CCR) 3, whereas monocyte chemotactic protein (MCP)-3 binds CCR1, CCR2, and CCR3. To identify the functional determinants of the chemokines, we generated four reciprocal chimeric chemokines-M10E9, M22E21, E8M11, and E20M23-by shuffling the N-terminus and N-loop of eotaxin and MCP-3. M22E21 and E8M11, which shared the N-loop from MCP-3, bound to monocytes with high affinity, and activated monocytes. In contrast, M10E9 and E20M23, which lacked the N-loop, failed to bind and transduce monocyte responses, identifying the N-loop of MCP-3 as the selectivity determinant for CCR1/CCR2. A BIAcore assay with an N-terminal peptide of CCR3 (residues 1-35) revealed that all chimeras except E20M23 exhibited varying degrees of binding affinity with commensurate chemotaxis activity of eosinophils. Surprisingly, E20M23 could neither bind the CCR3 peptide nor activate eosinophils, despite having both N-terminal motifs from eotaxin. These results suggest that the two N-terminal motifs of eotaxin must cooperate with other regions to successfully bind and activate CCR3.
Chung
Il Yup
IY
Department of Biochemistry and Molecular Biology, Hanyang University, Ansan, Kyunggi-do, Republic of Korea. iychu@hanyang.ac.kr
Kim
Yong Hyun
YH
Choi
Moon Kyung
MK
Noh
Yoon Jung
YJ
Park
Choon-Sik
CS
Kwon
Do Yoon
DY
Lee
Duck Yeon
DY
Lee
Young Seek
YS
Chang
Hun Soo
HS
Kim
Key-Sun
KS
D000595:Amino Acid Sequence; D002118:Calcium / Q000378:metabolism; D054413:Chemokine CCL11; D054410:Chemokine CCL7; D019742:Chemokines, CC / Q000502:physiology*; D002633:Chemotaxis; D016207:Cytokines; D004305:Dose-Response Relationship, Drug; D004804:Eosinophils / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D006801:Humans; D020128:Inhibitory Concentration 50; D007700:Kinetics; D008969:Molecular Sequence Data; D018945:Monocyte Chemoattractant Proteins / Q000378:metabolism / Q000502:physiology*; D009000:Monocytes / Q000378:metabolism; D010455:Peptides / Q000737:chemistry; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D054390:Receptors, CCR2; D054397:Receptors, CCR3; D019707:Receptors, Chemokine / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013997:Time Factors
C515456:CCL11 protein, human; C515450:CCL7 protein, human; C515334:CCR2 protein, human; C515350:CCR3 protein, human; D054413:Chemokine CCL11; D054410:Chemokine CCL7; D019742:Chemokines, CC; D016207:Cytokines; D018945:Monocyte Chemoattractant Proteins; D010455:Peptides; D054390:Receptors, CCR2; D054397:Receptors, CCR3; D019707:Receptors, Chemokine; D011993:Recombinant Fusion Proteins; C071570:SNF1-related protein kinases; D017346:Protein Serine-Threonine Kinases; D002118:Calcium