A. Benbaruch et al., INTERLEUKIN-8 RECEPTOR-BETA - THE ROLE OF THE CARBOXYL-TERMINUS IN SIGNAL-TRANSDUCTION, The Journal of biological chemistry, 270(16), 1995, pp. 9121-9128
Two interleukin-8 (IL-8) receptors, alpha and beta, have been identifi
ed and cloned. Both receptors are thought to transduce signals by coup
ling to GTP-binding proteins. The aim of this study is to determine wh
ether the carboxyl terminus (C') of IL-8 receptor beta (IL-8R beta) is
involved in signaling in response to IL-8. We have constructed a numb
er of IL-8R beta genes that encode truncated forms of the IL-8R beta.
The deletions consisted of amino acids 349-355, 336-355, 325-355, and
317-355 (termed beta 2, beta 3, beta 4, and beta 5, respectively). 293
human embryonic kidney cells were transfected with the wild type IL-8
R beta (beta 1) and with these mutants. Cells transfected with the mut
ated receptors expressed the receptors and bound IL-8 with the same hi
gh affinity as cells transfected with the wild type receptor. The capa
city of the mutated receptors to convey functional signals was evaluat
ed by comparing the chemotaxis index of cells expressing the C' trunca
ted receptors to the index of cells expressing the wild type receptor.
The results indicate that while cells expressing beta 1, beta 2, beta
3, and beta 4 were chemoattracted in response to IL-8, cells expressi
ng beta 5 did not migrate in response to IL-8 stimulation. Therefore,
the data suggest that amino acids 317-324 are involved in signaling by
IL-8R beta.