title: P120 catenin is associated with desmogleins when desmosomes are assembled in high-Ca2+ medium but not when disassembled in low-Ca2+ medium in DJM-1 cells.
abstract: We recently showed that p120 catenin (p120ctn), which is an armadillo family protein member that binds to E-cadherin (E-cad), is also localized to desmosomes by directly or indirectly binding to desmogleins (Dsg). We examined whether p120ctn is associated with Dsg1 and Dsg3, as compared with E-cad and plakoglobin (PG), in keratinocytes grown in high or low Ca2+, using a human squamous cell carcinoma cell line, DJM-1 cells. The cell lysate of DJM-1 cells grown in high- or low-Ca2+ media was immunoprecipitated with anti-Dsg1/2 and Dsg3 antibodies, and we examined whether p120ctn is associated with Dsg1 and Dsg3. Then, we observed the co-localization between Dsg3 and p120ctn in cells grown in high- or low-Ca2+ medium on double-staining immunofluorescence microscopy using anti-p120ctn and anti-Dsg3 antibodies. Immunoprecipitates with anti-Dsg1/2 and Dsg3 antibodies in cells grown in high-Ca2+ medium contained p120ctn. In contrast, in low-Ca2+ medium, p120ctn was co-immunoprecipitated with neither Dsg1 nor Dsg3, but was co-immunoprecipitated with E-cad in cells grown in both high- and low-Ca2+ media. Dsg3 was associated with PG in cells grown in both low- and high-Ca2+ media. On immunofluorescence microscopy, p120ctn and Dsg3 were independently observed in cells grown in low-Ca2+ medium; p120ctn, but not Dsg3, was observed in a linear pattern at the cell-cell boundary. However, they were co-localized at cell-cell contacts in cells grown in high-Ca2+ medium. Thus, these proteins are not co-localized in low Ca2+ medium. These results suggest that p120ctn plays an important role in Ca2+-induced desmosome formation.
authors.affiliation: Department of Dermatology, Gifu University School of Medicine, Gifu City, Japan.
authors.forename: Miho
authors.initials: M
authors.lastname: Kanno
authors.forename: Yumi
authors.initials: Y
authors.lastname: Aoyama
authors.forename: Yasuka
authors.initials: Y
authors.lastname: Isa
authors.forename: Yukari
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Kitajima
mesh_terms: D000911:Antibodies, Monoclonal; D015153:Blotting, Western; D015820:Cadherins / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D051177:Catenins; D015815:Cell Adhesion Molecules / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D003470:Culture Media / Q000737:chemistry; D051183:Desmoglein 1 / Q000378:metabolism*; D051184:Desmoglein 3 / Q000378:metabolism*; D003896:Desmosomes / Q000378:metabolism*; D006801:Humans; D047468:Immunoprecipitation; D015603:Keratinocytes / Q000378:metabolism* / Q000502:physiology; D008856:Microscopy, Fluorescence; D010750:Phosphoproteins / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D020033:Protein Isoforms / Q000378:metabolism; D051185:gamma Catenin / Q000378:metabolism; D000095002:Delta Catenin
chemical_list: D000911:Antibodies, Monoclonal; D015820:Cadherins; D051177:Catenins; D015815:Cell Adhesion Molecules; D003470:Culture Media; D051183:Desmoglein 1; D051184:Desmoglein 3; D010750:Phosphoproteins; D020033:Protein Isoforms; D051185:gamma Catenin; D002118:Calcium; D000095002:Delta Catenin; C000722347:CTNND1 protein, human