[HTML][HTML] Ca2+-sensitive inactivation and facilitation of L-type Ca2+ channels both depend on specific amino acid residues in a consensus calmodulin-binding motif in …
L-type Ca 2+ channels are unusual in displaying two opposing forms of autoregulatory
feedback, Ca 2+-dependent inactivation and facilitation. Previous studies suggest that both
involve direct interactions between calmodulin (CaM) and a consensus CaM-binding
sequence (IQ motif) in the C terminus of the channel's α 1C subunit. Here we report the
functional effects of an extensive series of modifications of the IQ motif aimed at dissecting
the structural determinants of the different forms of modulation. Although the combined …
feedback, Ca 2+-dependent inactivation and facilitation. Previous studies suggest that both
involve direct interactions between calmodulin (CaM) and a consensus CaM-binding
sequence (IQ motif) in the C terminus of the channel's α 1C subunit. Here we report the
functional effects of an extensive series of modifications of the IQ motif aimed at dissecting
the structural determinants of the different forms of modulation. Although the combined …