TY - JOUR
T1 - Heteromeric assembly of Kv2.1 with Kv9.3
T2 - Effect on the state dependence of inactivation
AU - Kerschensteiner, Daniel
AU - Stocker, Martin
PY - 1999/7
Y1 - 1999/7
N2 - Modulatory α-subunits of Kv channels remain electrically silent after homomeric expression. Their interactions with Kv2 α-subunits via the amino- terminal domain promote the assembly of heteromeric functional channels. The kinetic features of these heteromers differ from those of Kv2 homomers, suggesting a distinct role in electrical signaling. This study investigates biophysical properties of channels emerging from the coexpression of Kv2.1 with the modulatory α-subunit Kv9.3. Changes relative to homomeric Kv2.1 concern activation, deactivation, inactivation, and recovery from inactivation. A detailed description of Kv2.1/Kv9.3 inactivation is presented. Kv2.1/Kv9.3 heteromers inactivate in a fast and complete fashion from intermediate closed states, but in a slow and incomplete manner from open states. Intermediate closed states of channel gating can be approached through partial activation or deactivation, according to a proposed qualitative model. These transitions are rate-limiting for Kv2.1/Kv9.3 inactivation. Finally, based on the kinetic description, we propose a putative function for Kv2.1/KV9.3 heteromers in rat heart.
AB - Modulatory α-subunits of Kv channels remain electrically silent after homomeric expression. Their interactions with Kv2 α-subunits via the amino- terminal domain promote the assembly of heteromeric functional channels. The kinetic features of these heteromers differ from those of Kv2 homomers, suggesting a distinct role in electrical signaling. This study investigates biophysical properties of channels emerging from the coexpression of Kv2.1 with the modulatory α-subunit Kv9.3. Changes relative to homomeric Kv2.1 concern activation, deactivation, inactivation, and recovery from inactivation. A detailed description of Kv2.1/Kv9.3 inactivation is presented. Kv2.1/Kv9.3 heteromers inactivate in a fast and complete fashion from intermediate closed states, but in a slow and incomplete manner from open states. Intermediate closed states of channel gating can be approached through partial activation or deactivation, according to a proposed qualitative model. These transitions are rate-limiting for Kv2.1/Kv9.3 inactivation. Finally, based on the kinetic description, we propose a putative function for Kv2.1/KV9.3 heteromers in rat heart.
UR - http://www.scopus.com/inward/record.url?scp=0033014674&partnerID=8YFLogxK
U2 - 10.1016/S0006-3495(99)76886-4
DO - 10.1016/S0006-3495(99)76886-4
M3 - Article
C2 - 10388754
AN - SCOPUS:0033014674
SN - 0006-3495
VL - 77
SP - 248
EP - 257
JO - Biophysical Journal
JF - Biophysical Journal
IS - 1
ER -