Physiology 3140A Lecture Notes - Lecture 12: Ion Channel, Transmembrane Domain, Potassium Channel

• School: Western University
• Department: Physiology
• Course: Physiology 3140A
• Professor: John Di Guglielmo

Document Summary

In this lecture we will cover the molecular structure of ion channels, including different subunits, domains and amino acid residues. We will also discuss how the structure differences relate to their unique channel properties. Number of subunits or domains in an ion channel. Different number of subunits (or domains) is found in different groups of ion channels: exceptions exist for each. Most vg ion channels are organized by 4 subunits/domains. Most transmitter-gated ion channels have 5 domains. Gap junctions have 6 subunits per connexon (hemichannel) *note: pore size increases as number of subunits/domains increases. The smaller the pore the more selective. Oligomerization of subunits voltage-gated ion channels transmitter-gated ion channels gap junction hemichannels. Homo = same (subunit: homomeric = all subunits the same. Hetero = different (subunits: heteromeric = at least one subunit is different. Oligo = more than one: e. g. dimer, trimer, tetramer.