Regulation of a major cloned voltage-gated K+ channel from human T lymphocytes.
When expressed into Xenopus oocytes, HLK3 K+ channel (Kv1-3) induced a slowly inactivating voltage-dependent K+ current. We have studied the modulation of this K+ current by co-expressing a cloned 5-HT2 receptor together with HLK3 K+ channel protein. Application of 5-HT caused a long-lasting inhibition of the voltage-gated K+ current. This inhibitory modulation was mimicked by intracellular injection of inositol triphosphate or Ca2+, as well as by incubation with phorbol esters or diacylglycerol analogs. Oocytes pretreatment with staurosporine and EGTA fully prevented 5-HT inhibitory action. Elevation of cAMP and cGMP levels into oocytes did not produce any detectable effect on the current recorded in the absence or the presence of 5-HT. These data suggest that the second messengers generated by phospholipase C activation may be important modulators of HLK3 K+ channels in the immune and the central nervous systems.
Attali
B
B
Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France.
Honoré
E
E
Lesage
F
F
Lazdunski
M
M
Barhanin
J
J
D000818:Animals; D002118:Calcium / Q000378:metabolism; D003001:Cloning, Molecular; D004553:Electric Conductivity; D006801:Humans; D015640:Ion Channel Gating; D015221:Potassium Channels / Q000235:genetics / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism; D011985:Receptors, Serotonin / Q000378:metabolism; D013601:T-Lymphocytes / Q000378:metabolism*; D010738:Type C Phospholipases / Q000378:metabolism; D014981:Xenopus / Q000235:genetics
D015221:Potassium Channels; D011985:Receptors, Serotonin; D011493:Protein Kinase C; D010738:Type C Phospholipases; D002118:Calcium