Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

Coexpression in Xenopus oocytes of the cloned cardiac inward rectifier subunits K(ir) 3.1 and K(ir) 3,4 results in G protein-stimulated channel activity closely resembling the muscarinic channel underlying the inwardly rectifying K+ current in atrial myocytes. To determine the stoichiometry and relative subunit positions within the channel, K(ir). 3.1 and K(ir) 3.4 were eoexpressed in varying ratios with cloned Gβ1γ2 subunits and also as tandemly linked tetramers with different relative subunit positions. The results reveal that the most efficient channel comprises two subunits of each type in an alternating array within the tetramer. To localize regions important for subunit coassembly and G protein sensitivity, chimeric subunits containing domains from either K(ir) 3.1, K(ir) 3.4, or the G protein- insensitive subunit K(ir) 4.1 were expressed. The results demonstrate that the transmembrane domains dictate the potentiation of the coassembled channels and that, although the NH4- or COOH-termini of both subunits alone can confer G protein sensitivity, both termini are required for maximal stimulation by Gβ1γ2.


Journal article


American Journal of Physiology - Heart and Circulatory Physiology

Publication Date