Trimeric Intracellular Cation Channel Type B (TRICB)

Yazawa et al. (2007) identified TRICA and TRICB in rabbit skeletal muscle and cloned homologs from several species, including human. TRIC subtypes contain 3 proposed transmembrane segments, and form homotrimers with a bullet-like structure. Northern blot analysis of mouse tissues indicated that TRICB is expressed in most tissues. In further immunochemical studies antibodies, TRICB behaved as an endoplasmic reticulum-resident protein in brain tissues.Tricb-null mice showed neonatal lethality, while Trica-null mice were viable and fertile. Trica/Tricb double heterozygotes exhibited a weak heart beat at embryonic day 9.5 and subsequent loss of cardiomyocyte viability leading to terminal embryonic cardiac lethality beyond embryonic day 10.5. These data suggested that TRIC subtypes share complementary physiologic functions.