Endogenous expression of the β1A sodium channel subunit in HEK‐293 cells

FEBS Letters

Conti, Franco¹  Nizzari, Mario¹  Moran, Oscar¹ 

[1] Istituto di Cibernetica e Biofisica, CNR, Via De Marini 6, I-16149 Genoa, Italy

关键词: Sodium channel;    β1-Subunit;    Alternative splicing;    Heterologous expression;    HEK-293;   

DOI  :  10.1016/S0014-5793(00)01518-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The expression of the sole α-subunit of muscle or brain sodium channels in frog oocytes mediates currents with a bimodal inactivation with an abnormal slow mode that is strongly depressed only by co-expression of the β1-subunit. In contrast, in the expression of the α-subunit in the human embryonic kidney cell line, HEK-293, the slow mode is almost absent, suggesting an endogenous expression of the β1-subunit. We have tested this hypothesis by reverse transcriptase-polymerase chain reaction. We found an abundant expression of mRNA encoding the β1A splicing of the putative regulatory sodium channel subunit but no mRNA encoding the β1-subunit in HEK cells. This finding is consistent with the idea that the endogenous β1A-subunit is sufficient for suppressing the slowly inactivating mode of sodium currents by co-assembly with α-subunits, and calls attention to the reliability of effects attributed in HEK cells to α–β1 co-expression.

【 授权许可】

Unknown