Inherited human long-QT2 syndrome (LQTS) results from mutations in the gene encoding the HERG channel. Several LQT2-associated mutations have been mapped to the amino terminal cytoplasmic Per-Arnt-Sim (PAS) domain of the HERG1a channel subunit. Here we have characterized the trafficking properties of some LQT2-associated PAS domain mutants and analyzed rescue of the trafficking mutants by low temperature (27°C) or by the pore blocker drug E4031. We show that the LQT2-associated mutations in the PAS domain of the HERG channel display molecular properties that are distinct from the properties of LQT2-associated mutations in the trans-membrane region. Unlike the latter, many of the tested PAS domain LQT2-associated mutations do not result in trafficking deficiency of the channel. Moreover, the majority of the PAS domain mutations that cause trafficking deficiencies are not rescued by a pore blocking drug. We have also explored the in vitro folding stability properties of isolated mutant PAS domain proteins using a thermal unfolding fluorescence assay and a chemical unfolding assay.
Submitter: Shu-Ching Ou
Submission Date: Dec. 11, 2018, 12:21 p.m.
|Number of data points||132|
|Proteins||Potassium voltage-gated channel subfamily H member 2|
|Assays/Quantities/Protocols||Experimental Assay: Unfolding: ΔG(H2O) ; Experimental Assay: Unfolding: m ; Experimental Assay: Unfolding: Cm ; Experimental Assay: Unfolding: Tm ; Experimental Assay: Secondary Structure: % of Alpha-Helix ; Experimental Assay: Secondary Structure: % of Beta-Sheet ; Experimental Assay: Secondary Structure: % of Unordered ; Derived Quantity: SD of Unfolding: ΔG(H2O) ; Derived Quantity: SD of Unfolding: m ; Derived Quantity: SD of Unfolding: Cm ; Derived Quantity: SD of Unfolding: Tm ; Derived Quantity: Unfolding: ΔTm ; Derived Quantity: SD of Unfolding: ΔTm ; Derived Quantity: SD of SD of Unfolding: Tm|
|Libraries||Variants for PAS domain of the HERG1a channel subunit|