TY - JOUR
T1 - Cloning and expression of a rat cardiac delayed rectifier potassium channel
AU - Paulmichl, Markus
AU - Nasmith, Patricia
AU - Hellmiss, Renate
AU - Reed, Karen
AU - Boyle, Walter A.
AU - Nerbonne, Jeanne M.
AU - Peralta, Ernest G.
AU - Clapham, David E.
PY - 1991
Y1 - 1991
N2 - We have cloned a cDNA (designated RAK) coding for a delayed-rectifier K current (IRAK) from adult rat heart atrium and expressed it in Xenopus oocytes. RAK differs from the cloned rat brain K current, BK2 [McKinnon, D. (1989) J. Biol. Chem. 264, 8230-8236], by one amino acid at residue 411. RAK expressed in oocytes compares closely to the intrinsic adult rat atrial delayed-rectifier current measured by using whole-cell recording of single isolated cells. Northern blot analysis confirmed the presence of the channel in adult rat atrium, and to a lesser extent, in rat ventricle. IRAK activates with time constants ranging from 58 ms at -20 mV to 6 ms at +60 mV and does not show significant inactivation over 800 ms. It is blocked by 4-aminopyridine > barium > > tetraethylanunonium chloride, which is similar to the relative potencies of these blockers on the native delayed rectifier current. We conclude that the main delayed rectifier K current in adult rat atria is virtually identical to a neuronal delayed rectifier, BK2.
AB - We have cloned a cDNA (designated RAK) coding for a delayed-rectifier K current (IRAK) from adult rat heart atrium and expressed it in Xenopus oocytes. RAK differs from the cloned rat brain K current, BK2 [McKinnon, D. (1989) J. Biol. Chem. 264, 8230-8236], by one amino acid at residue 411. RAK expressed in oocytes compares closely to the intrinsic adult rat atrial delayed-rectifier current measured by using whole-cell recording of single isolated cells. Northern blot analysis confirmed the presence of the channel in adult rat atrium, and to a lesser extent, in rat ventricle. IRAK activates with time constants ranging from 58 ms at -20 mV to 6 ms at +60 mV and does not show significant inactivation over 800 ms. It is blocked by 4-aminopyridine > barium > > tetraethylanunonium chloride, which is similar to the relative potencies of these blockers on the native delayed rectifier current. We conclude that the main delayed rectifier K current in adult rat atria is virtually identical to a neuronal delayed rectifier, BK2.
UR - http://www.scopus.com/inward/record.url?scp=0025871663&partnerID=8YFLogxK
U2 - 10.1073/pnas.88.17.7892
DO - 10.1073/pnas.88.17.7892
M3 - Article
C2 - 1715584
AN - SCOPUS:0025871663
SN - 0027-8424
VL - 88
SP - 7892
EP - 7895
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 17
ER -