Structure-function relationships of the mouse inositol 1,4,5-trisphosphate receptor.
The homotetrameric complex of inositol 1,4,5-triphosphate (InsP3) receptors displays a Ca2+ release activity in response to InsP3 molecules. Structure-function relationships of the mouse cerebellar InsP3 receptor have been studied by analyses of a series of internal deletion or C-terminal truncation mutant proteins expressed in NG108-15 cells. Within the large cytoplasmic portion of the InsP3 receptor, approximately 650 N-terminal amino acids are highly conserved between mouse and Drosophila, and this region has the critical sequences for InsP3 binding that probably form the three-dimensionally restricted binding site. The N-terminal region of each InsP3 receptor subunit also binds one InsP3 molecule. Cross-linking experiments have revealed that InsP3 receptors are intermolecularly associated at the transmembrane domains and/or the successive C termini. The interaction between the receptor subunit and InsP3 may cause a conformational change in the tetrameric complex, resulting in the opening of Ca2+ channels.
Miyawaki
A
A
Division of Behavior and Neurobiology, National Institute for Basic Biology, Okazaki, Japan.
Furuichi
T
T
Ryou
Y
Y
Yoshikawa
S
S
Nakagawa
T
T
Saitoh
T
T
Mikoshiba
K
K
D000595:Amino Acid Sequence; D000818:Animals; D015220:Calcium Channels; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002531:Cerebellum / Q000378:metabolism*; D005910:Glioma; D006822:Hybrid Cells / Q000378:metabolism; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism*; D053496:Inositol 1,4,5-Trisphosphate Receptors; D046911:Macromolecular Substances; D051379:Mice; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009447:Neuroblastoma; D011487:Protein Conformation; D051381:Rats; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D018160:Receptors, Cytoplasmic and Nuclear; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D013329:Structure-Activity Relationship; D014162:Transfection
D015220:Calcium Channels; D053496:Inositol 1,4,5-Trisphosphate Receptors; D046911:Macromolecular Substances; D011956:Receptors, Cell Surface; D018160:Receptors, Cytoplasmic and Nuclear; D015544:Inositol 1,4,5-Trisphosphate