No abstract

The Q Q subunit was initially identified as an auxiliary subunit of the skeletal muscle calcium channel complex. Evidence for the existence of further Q Q subunits arose following the characterization of a genetic defect that induces epileptic seizures in stargazer mice. We present here the first account of a family of at least five putative Q Q subunits that are predominantly expressed in brain. The Q Q-2 and Q Q-4 subunits shift the steady-state inactivation curve to more hyperpolarized potentials upon coexpression with the P/Q type K K 1A subunit. The coexpression of the Q Q-5 subunit accelerates the time course of current activation and inactivation of the K K 1G T-type calcium channel. z 2000 Federation of European Biochemical Societies.

No abstract