HCN2 activation modulation: An electrophysiological and molecular study of the well-preserved LCI sequence in the pore channel
Por:
Hernandez, Adan, Hernandez-Centeno, Ricardo, Espino-Saldana, Angeles E., Martinez-Torres, Ataulfo
Publicada:
15 ago 2020
Resumen:
Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels
belong to the superfamily of voltage-gated potassium (Kv) and cyclic
nucleotide-gated (CNG) channels. HCN channels contain the
glycine-tyrosine-glycine (GYG) sequence that forms part of the
selectivity filter, a similar structure than some potassium channels;
however, they permeate both sodium and potassium, giving rise to an
inward current. Yet a second amino acid sequence,
leucine-cysteine-isoleucine (LCI), next to GYG, is well-preserved in all
HCNs but not in the selective potassium channels. In this study we used
site-directed mutagenesis and electrophysiology in frog oocytes to
determine whether the LCI sequence affects the kinetics of HCN2
currents. Permeability and voltage dependence were evaluated, and we
found a role of LCI in the gating mechanism combined with changes in ion
permeability. The I residue resulted critical to this function.
Filiaciones:
Hernandez, Adan:
Univ Nacl Autonoma Mexico, Inst Neurobiol, Dept Neurobiol Celular & Mol, Lab Neurobiol Mol & Celular, Santiago De Queretaro 76230, Queretaro, Mexico
Hernandez-Centeno, Ricardo:
Univ Nacl Autonoma Mexico, Inst Neurobiol, Dept Neurobiol Celular & Mol, Lab Neurobiol Mol & Celular, Santiago De Queretaro 76230, Queretaro, Mexico
Espino-Saldana, Angeles E.:
Univ Nacl Autonoma Mexico, Inst Neurobiol, Dept Neurobiol Celular & Mol, Lab Neurobiol Mol & Celular, Santiago De Queretaro 76230, Queretaro, Mexico
Martinez-Torres, Ataulfo:
Univ Nacl Autonoma Mexico, Inst Neurobiol, Dept Neurobiol Celular & Mol, Lab Neurobiol Mol & Celular, Santiago De Queretaro 76230, Queretaro, Mexico
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