Potassium Large Conductance Calcium Activated Channel Subfamily M Beta 3 (KCNMb3)

MaxiK channels are large conductance, voltage and calcium-sensitive potassium channels which are fundamental to the control of smooth muscle tone and neuronal excitability. MaxiK channels can be formed by 2 subunits: the pore-forming alpha subunit and the modulatory beta subunit.

KCNMb3 is an auxiliary beta subunit which may partially inactivate or slightly decrease the activation time of MaxiK alpha subunit currents. Alternative splicing results in multiple transcript variants. A related pseudogene has been identified on chromosome 22.KCNMB3 encodes a predicted 275-amino acid protein. Northern blot analysis detected 2.0- and 5.3-kb KCNMB3 transcripts, with highest expression in pancreas; a 3.1-kb transcript was also detected in most tissues.