title: Nuclear localization of bradykinin B(2) receptors reflects binding to the nuclear envelope protein lamin C.
abstract: The mechanism of action of bradykinin (BK), a pro-inflammatory mediator, is thought to be mediated by specific cell surface membrane bradykinin B2 receptors. Some evidence suggests that there are both intracellular and nuclear bradykinin B2 receptors. This study identified proteins that interact with the C-terminus of the bradykinin B2 receptor (in particular, the nuclear membrane protein lamin C), using the yeast two-hybrid system. The motif of the C-terminal domain (CT) mutant 303-320 in bradykinin B2 receptor was identified as a lamin C protein binding motif. Immunohistochemistry revealed colocalization of FLAG- bradykinin B2 receptor with HA-lamin C in the nucleus of HEK 293T cells. In situ proximity ligation assay (PLA) showed that FLAG-bradykinin B2 receptor formed heterodimers with HA-lamin C in the nucleus. In addition, live cell fluorescence imaging showed that bradykinin B2 receptor-EGFP was located in the nucleus and co-localized with HcRed-lamin C. Interestingly, neither BK addition nor bradykinin B2 receptor CT mutation reduced the binding to lamin C or changed the distribution of bradykinin B2 receptor. Taken together, these findings demonstrate that bradykinin B2 receptor-lamin C heterodimers form in the nucleus independent of BK stimulation and CT mutation. We propose that heterodimerization of bradykinin B2 receptor with lamin C is essential to nuclear localization of bradykinin B2 receptor and plays an important role in cell signaling and function.
authors.affiliation: Laboratory of Molecular Cell Biology, Department of Life Sciences Pharmacy, School of Pharmaceutical Sciences, Kobe Gakuin University, 1-1-3 Minatojima, Chuo-ku, Kobe 650-8586, Japan. Electronic address: takano@pharm.kobegakuin.ac.jp.
authors.forename: Masaoki
authors.initials: M
authors.lastname: Takano
authors.affiliation: Laboratory of Molecular Cell Biology, Department of Life Sciences Pharmacy, School of Pharmaceutical Sciences, Kobe Gakuin University, 1-1-3 Minatojima, Chuo-ku, Kobe 650-8586, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Kanoh
authors.affiliation: Faculty of Nutrition, Kobe Gakuin University, 518 Arise, Nishi-ku, Kobe 651-2180, Japan.
authors.forename: Katsumi
authors.initials: K
authors.lastname: Amako
authors.affiliation: Laboratory of Molecular Cell Biology, Department of Life Sciences Pharmacy, School of Pharmaceutical Sciences, Kobe Gakuin University, 1-1-3 Minatojima, Chuo-ku, Kobe 650-8586, Japan.
authors.forename: Mieko
authors.initials: M
authors.lastname: Otani
authors.affiliation: Laboratory of Molecular Cell Biology, Department of Life Sciences Pharmacy, School of Pharmaceutical Sciences, Kobe Gakuin University, 1-1-3 Minatojima, Chuo-ku, Kobe 650-8586, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Sano
authors.affiliation: Department of Physiological Chemistry, Faculty of Pharmaceutical Sciences, Kobe Gakuin University, 1-1-3 Minatojima, Chuo-ku, Kobe 650-8586, Japan.
authors.forename: Michiko
authors.initials: M
authors.lastname: Kanazawa-Hamada
authors.affiliation: Department of Pharmaceutical Health Care, Faculty of Pharmaceutical Sciences, Himeji Dokkyo University, 7-2-1 Kamiohno, Himeji 670-8524, Japan.
authors.forename: Shogo
authors.initials: S
authors.lastname: Matsuyama
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D057809:HEK293 Cells; D006801:Humans; D034904:Lamin Type A / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D009154:Mutation; D043782:Receptor, Bradykinin B2 / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
chemical_list: D018076:DNA, Complementary; D034904:Lamin Type A; D043782:Receptor, Bradykinin B2; C440308:lamin C
keywords: Bradykinin B(2) receptor; Heterodimer; Lamin C; Nuclear localization