| First Author | Patel AJ | Year | 2000 |
| Journal | J Biol Chem | Volume | 275 |
| Issue | 37 | Pages | 28722-30 |
| PubMed ID | 10887187 | Mgi Jnum | J:64576 |
| Mgi Id | MGI:1889498 | Doi | 10.1074/jbc.M003755200 |
| Citation | Patel AJ, et al. (2000) TWIK-2, an inactivating 2P domain K+ channel. J Biol Chem 275(37):28722-30 |
| abstractText | We cloned human and rat TWIK-2 and expressed this novel 2P domain K(+) channel in transiently transfected COS cells. TWIK-2 is highly expressed in the gastrointestinal tract, the vasculature, and the immune system. Rat TWIK-2 currents are about 15 times larger than human TWIK-2 currents, but both exhibit outward rectification in a physiological K(+) gradient and mild inward rectification in symmetrical K(+) conditions. TWIK-2 currents are inactivating at depolarized potentials, and the kinetic of inactivation is highly temperature-sensitive. TWIK-2 shows an extremely low conductance, which prevents the visualization of discrete single channel events. The inactivation and rectification are intrinsic properties of TWIK-2 channels. In a physiological K(+) gradient, TWIK-2 is half inhibited by 0.1 mm Ba(2+), quinine, and quinidine. Finally, cysteine 53 in the M1P1 external loop is required for functional expression of TWIK-2 but is not critical for subunit self-assembly. TWIK-2 is the first reported 2P domain K(+) channel that inactivates. The base-line, transient, and delayed activities of TWIK-2 suggest that this novel 2P domain K(+) channel may play an important functional role in cell electrogenesis. |
