title: Presence of the inositol 1,4,5-triphosphate receptor isoforms in the nucleoplasm.
abstract: Although the inositol 1,4,5-triphosphate (IP(3))-induced nuclear Ca(2+) release has been shown to play key roles in nuclear functions, the presence of IP(3) receptor (IP(3)R)/Ca(2+) channels in the nucleoplasm has not been found. Recently, the IP(3)R/Ca(2+) channels were reported to exist in the nucleoplasmic reticulum structure, an extension of the nuclear envelope. Here we investigated the potential existence of the IP(3)Rs in the nucleoplasm and found the presence of all three IP(3)R isoforms in neuroendocrine and non-neuroendocrine cells. The IP(3)Rs were widely scattered in the nucleoplasm, localizing in both the heterochromatin and euchromatin regions.
authors.affiliation: National Creative Research Initiative Center for Secretory Granule Research, and Department of Biochemistry, Inha University College of Medicine, Jung Gu, Incheon 400-712, South Korea.
authors.forename: Yang Hoon
authors.initials: YH
authors.lastname: Huh
authors.forename: Seung Hyun
authors.initials: SH
authors.lastname: Yoo
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015220:Calcium Channels / Q000378:metabolism*; D037282:Calreticulin / Q000378:metabolism; D002417:Cattle; D002478:Cells, Cultured; D019439:Chromaffin Cells / Q000378:metabolism; D006046:Gold / Q000737:chemistry; D015151:Immunoblotting; D053496:Inositol 1,4,5-Trisphosphate Receptors; D051379:Mice; D016253:Microscopy, Immunoelectron / Q000379:methods; D008969:Molecular Sequence Data; D041681:NIH 3T3 Cells; D015530:Nuclear Matrix / Q000378:metabolism*; D015388:Organelles / Q000378:metabolism; D020033:Protein Isoforms; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism*
chemical_list: D015220:Calcium Channels; D037282:Calreticulin; D053496:Inositol 1,4,5-Trisphosphate Receptors; D020033:Protein Isoforms; D018160:Receptors, Cytoplasmic and Nuclear; D006046:Gold