Amino-terminus oligomerisation is conserved in intracellular calcium release channels

Oligomerisation of all three mammalian ryanodine receptor isoforms, a structural requirement for normal intracellular Ca2+ release channel function, is displayed by the discrete N-terminal domain which assembles into homo- and hetero-tetramers. This is demonstrated in yeast, mammalian cells and native tissue by complementary yeast two-hybrid, chemical cross-linking and co-immunoprecipitation assays. The IP3 receptor N-terminus (amino acids 1-667) similarly exhibits tetrameric association as indicated by chemical cross-linking and co-immunoprecipitation assays. The presence of either a 15-residue splice insertion or of the cognate ligand, IP3, did not affect tetramerisation of the IP3 receptor N-terminus. Thus, N-terminus tetramerisation appears to be an essential, intrinsic property that is conserved in both the ryanodine receptor and IP3 receptor families of mammalian intracellular Ca2+ release channels.
Source: BJ Cell - Category: Biochemistry Authors: Tags: BJ Biomolecules Source Type: research