PROPERTIES AND REGULATION OF THE MINK POTASSIUM CHANNEL PROTEIN

The minK gene encodes a protein of 130 amino acids that has a single t ransmembrane segment and is expressed in many tissues including heart, uterus, and kidney. When Xenopus oocytes are injected with minK mRNA, a very slowly activating voltage-dependent potassium current is induc ed in these cells. The induced channels appear to result from the inte raction of the minK protein with other channel-forming subunits such a s the K(v)LQT1 channel. The minK protein is intimately associated with the structure of the resultant channels, and mutations in minK can al ter ion selectivity and modulation by second messengers. Strong candid ates for native currents regulated by the minK protein include the slo w component of the cardiac delayed rectifier and potassium currents re corded across epithelial cells in vestibular organs and cochlea.