To begin to study the molecular bases that determine the selective interaction of the β-subunits of voltage-gated K+ channels with α-subunits observed in situ, we have expressed these polypeptides in transfected mammalian cells. Analysis of the specificity of α/β-subunit interaction indicates that both the Kvβ1 and Kvβ2 β-subunits display robust and selective interaction with the five members of the Shaker-related (Kv1) α-subunit subfamily tested. The interaction of these β-subunits with Kv1 α-subunits does not require the β-subunit N-terminal domains. Thus, the previously observed failure of N-terminal mutants of Kvβ1 to modulate inactivation kinetics of Kv1 family members is not simply due to a lack of subunit interaction. Interaction of these β-subunits with members of two other subfamilies (Shab- and Shaw-related) could not be detected. Somewhat surprisingly, a member of the Shal-related subfamily was found to interact with β-subunits; however, this interaction had biochemical characteristics distinct from the β-subunit interaction with Kv1 family members. In all cases, Kvβ1 and Kvβ2 exhibited indistinguishable α-subunit selectivity. These studies point to a selective interaction between K+ channel α- and β-subunits mediated through conserved domains in the respective subunits.
|Original language||English (US)|
|Number of pages||6|
|Journal||Journal of Biological Chemistry|
|State||Published - Mar 22 1996|
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