Structural and functional characterization of human potassium channel subunit beta 1 (KCNA1B).
Neuropharmacology
; 35(7): 787-95, 1996.
Article
em En
| MEDLINE
| ID: mdl-8938711
ABSTRACT
Voltage-activated Shaker-related potassium channels (kv1) consist of alpha and beta subunits. We have analysed the structure of the human KCNA1B (hKv beta 1) gene. KCNA1B is > 250 kb in size and encodes at least three Kv beta 1 splice variants. The Kv beta 1 open reading frame is divided into 14 exons. In contrast, genes coding for family members of KCNA (Kv 1 alpha) subunits are markedly smaller and have intronless open reading frames. The expression of Kv 1 alpha and Kv beta mRNA was compared in Northern blots of poly(A+) RNA isolated from various human brain tissues. The results suggest an intricate and cell-specific regulation of Kv 1 alpha and Kv beta mRNA synthesis such that distinct combinations of alpha and beta subunits would occur in different nuclei of the brain. The splice variants hKv beta 1.1 and hKv beta 1.2 were functionally characterized in coexpression studies with hKv 1.5 alpha subunits in 293 cells. It is shown that the confer rapid inactivation on hKv 1.5 channels with different potencies. This may be due to differences in their amino terminal sequences and/or inactivating domains. It is also shown that the amino terminal Kv beta 1.1 and Kv 1.4 alpha inactivating domains compete with each other, probably for the binding to the same receptor site(s) on Kv 1 alpha-subunits.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Canais de Potássio
/
Canais de Potássio de Abertura Dependente da Tensão da Membrana
Limite:
Humans
Idioma:
En
Revista:
Neuropharmacology
Ano de publicação:
1996
Tipo de documento:
Article