Tweety Homolog 1 (TTYH1)

TTYH1 encodes a member of the tweety family of proteins. Members of this family function as chloride anion channels. The encoded protein functions as a calcium(2+)-independent, volume-sensitive large conductance chloride(-) channel. Two transcript variants encoding distinct isoforms have been identified for this gene.The human and mouse proteins are 91% identical. Hydrophobicity analysis of the tty-related proteins indicated that they represent a new family of membrane proteins with 5 potential membrane-spanning regions.TTYH1 supported membrane currents in transfected Chinese hamster ovary cells. While the channel activities of TTYH2 and TTYH3 were Ca(2+)-dependent, TTYH1 channel activity was independent of Ca(2+) concentration and was activated by osmolarity.