Melanoma growth stimulatory activity enhances the phosphorylation of the class II interleukin-8 receptor in non-hematopoietic cells.

摘要: The class II IL-8 receptor (IL-8R) binds both melanoma growth stimulatory activity (MGSA) and with high affinity. Reverse transcriptase polymerase chain reaction demonstrates that the IL-8R mRNA, which has previously been detected only in cells of hematopoietic lineage, is also expressed non-hematopoietic cell types shown to respond MGSA or IL-8. To study signaling mechanism by through cells, this was overexpressed 3ASubE human placental 293 kidney lines. Membrane preparations expressing transfectants exhibited a 2.3 +/- 0.2-fold increase GTP gamma 35S binding, sensitive pertussis toxin, response treatment (0.2 microM). This not observed transfected parental expression vector. In vivo phosphorylation studies demonstrated basally phosphorylated untreated transfectants, (5 nM) markedly enhanced receptor. MGSA-induced time concentration dependent could be mimicked calcium ionophore A23187. Phosphoamino acid analysis indicated on serine residue(s), suggesting kinase activated binding cells.