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Nascent Chain Folding of Potassium Channels.
Author(s) -
Deutsch Carol
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.a890-a
Subject(s) - translocon , transmembrane protein , biophysics , transmembrane channels , ion channel , potassium channel , folding (dsp implementation) , chemistry , voltage gated ion channel , biogenesis , kcsa potassium channel , cytosol , membrane potential , gating , ribosome , transmembrane domain , membrane , microbiology and biotechnology , membrane protein , biochemistry , biology , rna , engineering , electrical engineering , receptor , gene , enzyme
Potassium channels are tetrameric membrane proteins that provide a highly selective conduit for K + ions to diffuse across the hydrophobic barrier of cell membranes. As such, their function is critical for processes like neuronal excitability, secretion of hormones, and muscle contraction. One subset of K + channels, voltage‐gated (Kv) channels, is exquisitely sensitive to small changes of membrane potential. Although the structure and function of mature Kv channels have been studied extensively, little is known about the early folding events in channel biogenesis. We have developed several biochemical approaches to define the stages and compartments in which secondary, tertiary, and quaternary structures of Kv channels are acquired. The Kv channel contains classical hydrophobic transmembrane segments as well as charged transmembrane segments responsible for sensing voltage. How these diverse segments fold and wend their way through the ribosome, translocon, and beyond, is a mystery. I will discuss nascent peptide folding of Kv cytosolic and transmembrane segments both inside and outside of the ribosomal exit tunnel. [Supported by NIH grant GM 52302].