Role of intracellular domains in the function of the herg potassium channel.

The functional role of the large intracellular regions (which include the cyclic nucleotide binding domain, cNBD, and the Per-Arnt-Sim domain, PAS) in the herg channel is not well understood. We have studied possible interactions of the cNBD with other parts of the channel protein using lysine mutations to disrupt such interactions. Some lysine mutations caused significant right shifts in the voltage dependence of inactivation; almost all the mutants caused speeding up of deactivation time course.

Tubulin as a binding partner of the heag2 voltage-gated potassium channel.

The aim of this work was to investigate interactions of the human ether-a-go-go channel heag2 with human brain proteins. For this, we used heag2-GST fusion proteins in pull-down assays with brain proteins and mass spectrometry, as well as coimmunoprecipitation. We identified tubulin and heat shock 70 proteins as binding to intracellular C-terminal regions of the channel.