Potassium viroporins as model systems for understanding eukaryotic ion channel behaviour

Computational methods for unlocking the secrets of potassium channels: Structure, mechanism, and drug design

“…K + channels exhibit high selectivity for potassium ions due to their structure and specific interactions with potassium ions. The selectivity of ion transport is essential and necessary for many biological processes such as the propagation of nerve impulses, cell signaling 8,15 . However, the exact mechanism of selectivity of K + channels is still not fully understood, and there is no unified viewpoint on this issue.…”

“…Relatively, the K2P channel is composed of functional dimers, each with two repeats of the pore topology that form a pseudo‐tetrameric structure 12–14 . Independent of which class it belongs to, the typical structure of a K + channel includes two domains generally: the pore‐forming domain and the regulatory domain 8,15 . The pore‐forming domain is responsible for transportation of potassium ions and its structure is similar in all types of K + channels 15 .…”

“…8,15 The pore-forming domain is responsible for transportation of potassium ions and its structure is similar in all types of K + channels. 15 While, the selectivity filter (SF) located within the pore-forming domain is very important for determining the selectivity of the K + channels. 16 The gating of K + channels, or opening and closing, is typically controlled by the movement of helical bundles, such as the voltage-sensing domain (VSD) and pore-forming domains in Kv channels.…”

Combination of hydrophobicity and codon usage bias determines sorting of model K+ channel protein to either mitochondria or endoplasmic reticulum

“…The viral coded proteins have a monomer size of only around 100 amino acids, truly minimal, but still contain all the structural hallmarks of eukaryotic K + channels. With these features, the viral proteins are ideal orthogonal model systems to examine basic cell biological processes in eukaryotic cells 15 . A seminal observation, which makes these proteins so interesting as a model system for protein sorting, is that one channels, Kcv, is in mammalian cells co‐translationally synthesized at the translocon into the ER, 16 from where it travels via the secretory pathway to the plasma membrane 17 .…”

“…With these features, the viral proteins are ideal orthogonal model systems to examine basic cell biological processes in eukaryotic cells. 15 A seminal observation, which makes these proteins so interesting as a model system for protein sorting, is that one channels, Kcv, is in mammalian cells co-translationally synthesized at the translocon into the ER, 16 from where it travels via the secretory pathway to the plasma membrane. 17 In contrast the structurally similar Kesv protein is sorted post-translationally to the inner membrane of the mitochondria 18 via the canonical TIM/TOM translocases.…”