title: Molecular proximity of Kv1.3 voltage-gated potassium channels and beta(1)-integrins on the plasma membrane of melanoma cells: effects of cell adherence and channel blockers.
abstract: Tumor cell membranes have multiple components that participate in the process of metastasis. The present study investigates the physical association of beta1-integrins and Kv1.3 voltage-gated potassium channels in melanoma cell membranes using resonance energy transfer (RET) techniques. RET between donor-labeled anti-beta1-integrin and acceptor-labeled anti-Kv1.3 channels was detected on LOX cells adherent to glass and fibronectin-coated coverslips. However, RET was not observed on LOX cells in suspension, indicating that molecular proximity of these membrane molecules is adherence-related. Several K(+) channel blockers, including tetraethylammonium, 4-aminopyridine, and verapamil, inhibited RET between beta1-integrins and Kv1.3 channels. However, the irrelevant K(+) channel blocker apamin had no effect on RET between beta1-integrins and Kv1.3 channels. Based on these findings, we speculate that the lateral association of Kv1.3 channels with beta1-integrins contributes to the regulation of integrin function and that channel blockers might affect tumor cell behavior by influencing the assembly of supramolecular structures containing integrins.
authors.affiliation: Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA.
authors.forename: Vira V
authors.initials: VV
authors.lastname: Artym
authors.forename: Howard R
authors.initials: HR
authors.lastname: Petty
mesh_terms: D002448:Cell Adhesion / Q000502:physiology; D002462:Cell Membrane / Q000378:metabolism; D004735:Energy Transfer / Q000187:drug effects; D006801:Humans; D019012:Integrin beta1 / Q000378:metabolism*; D051664:Kv1.3 Potassium Channel; D008545:Melanoma / Q000378:metabolism* / Q000473:pathology; D026902:Potassium Channel Blockers / Q000494:pharmacology; D015221:Potassium Channels / Q000378:metabolism*; D024642:Potassium Channels, Voltage-Gated; D014018:Tissue Distribution; D014407:Tumor Cells, Cultured
chemical_list: D019012:Integrin beta1; C496973:KCNA3 protein, human; D051664:Kv1.3 Potassium Channel; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated