| Autor: |
Niu LG; Department of Neuroscience, UConn Health, Farmington CT, USA., Liu P; Department of Neuroscience, UConn Health, Farmington CT, USA., Shui Y; Department of Neuroscience, UConn Health, Farmington CT, USA., Mailler R; Department of Computer Science, University of Tulsa, Tulsa, OK, USA., Wang ZW; Department of Neuroscience, UConn Health, Farmington CT, USA., Chen B; Department of Neuroscience, UConn Health, Farmington CT, USA. bochen@uchc.edu. |
| Abstrakt: |
Auxiliary subunits are often needed to tailor K + channel functional properties and expression levels. Many auxiliary subunits have been identified for mammalian Slo1, a high-conductance K + channel gated by voltage and Ca 2+ . Experiments with heterologous expression systems show that some of the identified Slo1 auxiliary subunits can also regulate other Slo K + channels. However, it is unclear whether a single auxiliary subunit may regulate more than one Slo channel in native tissues. BKIP-1, an auxiliary subunit of C. elegans SLO-1, facilitates SLO-1 membrane trafficking and regulates SLO-1 function in neurons and muscle cells. Here we show that BKIP-1 also serves as an auxiliary subunit of C. elegans SLO-2, a high-conductance K + channel gated by membrane voltage and cytosolic Cl - and Ca 2+ . Comparisons of whole-cell and single-channel SLO-2 currents in native neurons and muscle cells between worm strains with and without BKIP-1 suggest that BKIP-1 reduces chloride sensitivity, activation rate, and single-channel open probability of SLO-2. Bimolecular fluorescence complementation assays indicate that BKIP-1 interacts with SLO-2 carboxyl terminal. Thus, BKIP-1 may serve as an auxiliary subunit of SLO-2. BKIP-1 appears to be the first example that a single auxiliary subunit exerts opposite effects on evolutionarily related channels in the same cells. |
