Low-voltage activated calcium channels: Achievements and problems

Low-voltage activated Ca2+ channels, which posses unique properties quite different from those of common (high-voltage activated) channels, were discovered lj years ago but the first alpha(1) subunit has only recently been identified which might provide their structural basis. However, simultaneously, extensive data are being accumulated on the functional diversity of low-voltage activated Ca2+ currents with regard to their pharmacological sensitivity, ionic selectivity, activation and inactivation kinetics. Such diversity corresponds to equally prominent heterogeneity in the location and function of the channels. This commentary summarizes the data available in an attempt to predict a possibly wider structural subdivision of low-voltage activated Ca2+ channels into subtypes. (C) 1999 IBRO. Published by Elsevier Science Ltd.