PRESYNAPTIC A-CURRENT BASED ON HETEROMULTIMERIC K-VIVO( CHANNELS DETECTED IN)

Citation
M. Sheng et al., PRESYNAPTIC A-CURRENT BASED ON HETEROMULTIMERIC K-VIVO( CHANNELS DETECTED IN), Nature, 365(6441), 1993, pp. 72-75
Citations number
18
Categorie Soggetti
Multidisciplinary Sciences
Journal title
NatureACNP
ISSN journal
00280836
Volume
365
Issue
6441
Year of publication
1993
Pages
72 - 75
Database
ISI
SICI code
0028-0836(1993)365:6441<72:PABOHK>2.0.ZU;2-8
Abstract
A WIDE variety of voltage-gated K+ channels are involved in the regula tion of neuronal excitability and synaptic transmission. Their heterog eneity arises in part from the large number of genes encoding differen t K+ channel subunits (reviewed in ref. 1). In addition, heterologous expression studies indicate that assembly of distinct subunits into he teromultimeric channels may contribute further to K+ channel diversity 2-6. A question has been whether heteromeric K+ channels actually form in vivo, and if so, whether specific combinations of subunits could a ccount for major K+ currents identified in neurons. We present here bi ochemical evidence that Kv1.4 and Kv1.2, two K+ channel subunits of th e Shaker subfamily, co-assemble in rat brain. The Kv1.4/Kv1.2 heteromu ltimer combines features of both parent subunits, resulting in an A-ty pe K+ channel6. Immunocytochemical evidence suggests that the heteromu ltimers are localized in axons and nerve terminals. We propose that Kv 1.4/Kv1.2 heteromultimers may form the molecular basis of a presynapti c A-type K+ channel involved in the regulation of neurotransmitter rel ease.