Overexpression of mouse IsK protein fused to green fluorescent protein induces apoptosis of human astroglioma cells.
Intracellular K(+) plays an important role in controlling ion homeostasis for maintaining cell volume and inhibiting activity of pro-apoptotic enzymes. Cytoplasmic K(+) concentration is regulated by K(+) uptake via Na(+) -K(+) -ATPase and K(+) efflux through K(+) channels in the plasma membrane. The IsK (KCNE1) protein is known to co-assemble with KCNQ1 (KvLQT1) protein to form a K(+) channel underlying the slowly activating delayed rectifier K(+) outward current which delays voltage activation. In order to further study the activity and cellular localization of IsK protein, we constructed a C-terminal fusion of IsK with EGFP (enhanced green fluorescent protein). Expression of the fusion protein appeared as clusters located in the plasma membrane and induced degeneration of both transiently or stably transfected cells.
Stathopoulos
A
A
Laboratory of Experimental Neurosurgery, and Multidisciplinary Research Institute (IRIBHM), Université Libre de Bruxelles, 808 route de Lennik, 1070 Brussels, Belgium. tstath@hotmail.com
Melas
C
C
Attali
B
B
Blum
D
D
Levivier
M
M
Brotchi
J
J
Velu
T
T
Tenenbaum
L
L
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D001254:Astrocytoma / Q000473:pathology*; D045744:Cell Line, Tumor; D015870:Gene Expression / Q000502:physiology*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D051379:Mice; D024642:Potassium Channels, Voltage-Gated / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors; D014162:Transfection / Q000379:methods
C092068:Kcne1 protein, mouse; D024642:Potassium Channels, Voltage-Gated; D049452:Green Fluorescent Proteins