Résumé
Increased expression of low voltage-activated, T-type Ca
2+ channels has been correlated with a variety of cellular events including cell proliferation and cell cycle kinetics. The recent cloning of three genes encoding T-type α
1 subunits, α
1G, α
1H and α
1I, now allows direct assessment of their involvement in mediating cellular proliferation. By overexpressing the human α
1G and α
1H subunits in human embryonic kidney (HEK-293) cells, we describe here that, although T-type channels mediate increases in intracellular Ca
2+ concentrations, there is no significant change in bromodeoxyuridine incorporation and flow cytometric analysis. These results demonstrate that expressions of T-type Ca
2+ channels are not sufficient to modulate cellular proliferation of HEK-293 cells.