The conserved protein-conducting channel, referred to as the Sec61 channel in eukaryotes or the SecY channel in eubacteria and archaea, translocates proteins across cellular membranes and integrates proteins containing hydrophobic transmembrane segments into lipid bilayers. Structural studies illustrate how the protein-conducting channel accomplishes these tasks. Three different mechanisms, eac...

The modulation of presynaptic calcium channel activity by second messengers provides a fine tuning mechanism for neurotransmitter release. In neurons, the activation of certain G protein-coupled receptors reduces N-type channel activity by approximately 60%. In contrast, activation of protein kinase C (PKC) results in an approximately 50% increase in N-type channel activity, and subsequent G pr...

Both the voltage-dependent anion channel and the glucose-regulated protein 78 have been identified as plasminogen kringle 5 receptors on endothelial cells. In this study, we demonstrate that kringle 5 binds to a region localized in the N-terminal domain of the glucose-regulated protein 78, whereas microplasminogen does so through the C-terminal domain of the glucose-regulated protein 78. Both p...

The cGMP-gated cation channel mediating visual transduction in retinal rods was recently found to comprise at least two subunits, 1 and 2 (or alpha and beta). SDS gels of the purified channel show, in addition to a 63-kDa protein band (subunit 1), a 240-kDa protein band that binds Ca(2+)-calmodulin, a modulator of the channel. To examine any connection between subunit 2 and the 240-kDa protein,...

Chloride intracellular Channel 1 (CLIC1) is a metamorphic protein that changes from a soluble cytoplasmic protein into a transmembrane protein. Once inserted into membranes, CLIC1 multimerises and is able to form chloride selective ion channels. Whilst CLIC1 behaves as an ion channel both in cells and in artificial lipid bilayers, its structure in the soluble form has led to some uncertainty as...

BACKGROUND/AIMS Janus kinase 3 (JAK3), a tyrosine kinase contributing to the regulation of cell proliferation and apoptosis of lymphocytes and tumour cells, has been shown to modify the expression and function of several ion channels and transport proteins. Channels involved in the regulation of cell proliferation include the large conductance voltage- and Ca(2+)-activated K(+) channel BK. The ...