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K+ channel tetramerisation domain is the N-terminal, cytoplasmic tetramerisation domain (T1) of voltage-gated K+ channels. It defines molecular determinants for subfamily-specific assembly of alpha-subunits into functional tetrameric channels. It is distantly related to the BTB/POZ domain . ==Potassium channels== Potassium channels are the most diverse group of the ion channel family. They are important in shaping the action potential, and in neuronal excitability and plasticity. The potassium channel family is composed of several functionally distinct isoforms, which can be broadly separated into 2 groups: the practically non-inactivating 'delayed' group and the rapidly inactivating 'transient' group. These are all highly similar proteins, with only small amino acid changes causing the diversity of the voltage-dependent gating mechanism, channel conductance and toxin binding properties. Each type of K+ channel is activated by different signals and conditions depending on their type of regulation: some open in response to depolarisation of the plasma membrane; others in response to hyperpolarisation or an increase in intracellular calcium concentration; some can be regulated by binding of a transmitter, together with intracellular kinases; while others are regulated by GTP-binding proteins or other second messengers. In eukaryotic cells, K+ channels are involved in neural signalling and generation of the cardiac rhythm, act as effectors in signal transduction pathways involving G protein-coupled receptors (GPCRs) and may have a role in target cell lysis by cytotoxic T-lymphocytes. In prokaryotic cells, they play a role in the maintenance of ionic homeostasis. 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Potassium channel tetramerisation domain」の詳細全文を読む スポンサード リンク
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