Evidence for a K+ channel requirement in spreading of rat basophilic leukemia cells on fibronectin-coated surfaces.
We investigated the ionic requirements for the early events of cell-extracellular matrix interactions leading to cell spreading. We found that potassium ions were required specifically in several cell types. Adhesion to fibronectin- (FN) coated surfaces was independent of K+ in the medium. In contrast, cells that adhered to FN in the absence of K+ failed to spread. This requirement for K+ occurred only during a discrete time frame: in the first 15 minutes following adhesion. Moreover, we identified a specific trans-membrane flux of the radioactive K+ analog 86Rb+, the kinetics of which correlated with this requirement. Both this ion flux and cell spreading were blocked by the K+ -channel inhibitors tetraethylammonium (TEA) and 4-aminopyridine (4-AP). Our results suggest that this K+ ion flux and the channels that regulate it are important in regulating the initial responses to adhesion that lead to spreading.
Zigrino
P
P
The Scripps Research Institute, Department of Cell Biology, La Jolla, California 92037, USA.
Gaietta
G
G
Zambonin-Zallone
A
A
Pelletier
A J
AJ
Quaranta
V
V
D000818:Animals; D002460:Cell Line; D002465:Cell Movement; D005353:Fibronectins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D015640:Ion Channel Gating; D015471:Leukemia, Basophilic, Acute / Q000378:metabolism / Q000473:pathology*; D009842:Oligopeptides; D015221:Potassium Channels / Q000378:metabolism* / Q000502:physiology; D051381:Rats; D012413:Rubidium / Q000378:metabolism; D014407:Tumor Cells, Cultured
D005353:Fibronectins; D009842:Oligopeptides; D015221:Potassium Channels; C047981:arginyl-glycyl-aspartic acid; D012413:Rubidium