ANTIBODIES SPECIFIC FOR DISTINCT KV SUBUNITS UNVEIL A HETEROOLIGOMERIC BASIS FOR SUBTYPES OF ALPHA-DENDROTOXIN-SENSITIVE K+ CHANNELS IN BOVINE BRAIN

被引:140
作者
SCOTT, VES
MUNIZ, ZM
SEWING, S
LICHTINGHAGEN, R
PARCEJ, DN
PONGS, O
DOLLY, JO
机构
[1] UNIV LONDON IMPERIAL COLL SCI & TECHNOL, DEPT BIOCHEM, LONDON SW7 2AY, ENGLAND
[2] INST NEURALE SIGNALVERBEITUNG, ZENTRUM MOLEK NEUROBIOL, D-20246 HAMBURG, GERMANY
关键词
D O I
10.1021/bi00173a001
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
`The authentic subunit compositions of neuronal K+ channels purified from bovine brain were analyzed using a monoclonal antibody (mAb 5), reactive exclusively with the Kv1.2 subunit of the latter and polyclonal antibodies specific for fusion proteins containing C-terminal regions of four mammalian Kv proteins. Western blotting of the K+ channels isolated from several brain regions, employing the selective blocker alpha-dendrotoxin (alpha-DTX), revealed the presence in each of four different Kvs. Variable amounts of Kv1.1 and 1.4 subunits were observed in the K+ channels purified from cerebellum, corpus striatum, hippocampus, cerebral cortex, and brain stem; on the other hand, contents of Kv1.6 and 1.2 subunits appeared uniform throughout. Each Kv-specific antibody precipitated a different proportion (anti-Kv1.2 > 1.1 >> 1.6 > 1.4) of the channels detectable with radioiodinated alpha-DTX in every brain region, consistent with a widespread distribution of these oligomeric subtypes. Such heterooligomeric combinations were further documented by the lack of additivity upon their precipitation with a mixture of antibodies to Kv1.1 and Kv1.2; moreover, cross-blotting of the multimers precipitated by mAb 5 showed that they contain all four Kv proteins. Collectively, these findings demonstrate that subtypes of alpha-DTX-susceptible K+ channels are prevalent throughout mammalian brain which are composed of different K+ proteins assembled in complexes, shown previously to also contain auxiliary beta-subunits [Parcej, D. N., Scott, V. E. S., & Dolly, J. O. (1992) Biochemistry 31, 11084-11088].
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页码:1617 / 1623
页数:7
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