Engineered Passive Potassium Conductance in the KR2 Sodium Pump.

ABSTRACT: Light-driven sodium pumps (NaRs) are microbial rhodopsins that utilize light energy to actively transport sodium ions out of the cell. Here, we used targeted mutagenesis and electrophysiological methods in living cells to demonstrate that NaRs can be converted into light-activated cation channels by molecular engineering. Specifically, introduction of the R109Q mutation into the sodium ion pump of Dokdonia eikasta (KR2) results in passive ion conductance, with a high preference for potassium over sodium ions. However, in this mutant, residual active outward pumping of sodium ions competes with passive inward transport of potassium. Channel-like behavior could also be achieved by introduction of other mutations into the KR2 counterion complex, and further, these modifications were transferr

SUBMITTER: Vogt A 

PROVIDER: S-EPMC6531830 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature