OBJECTIVE: Autoantibodies in the systemic rheumatic diseases are clinically useful biomarkers of the diagnosis or of certain clinical characteristics. An unusual pattern of immunoprecipitation, in which the D, E, F, and G proteins of small nuclear RNPs (snRNP) but without other components of the snRNP, was noticed at the autoantibody screening. The purpose of this study was to examine the target antigens and clinical manifestations associated with this specificity. METHODS: Autoantibodies in sera from 1,966 American patients (including 434 with systemic lupus erythematosus, 121 with scleroderma, 86 with polymyositis/dermatomyositis [PM/DM]) and 248 Italian patients with autoimmune diseases were screened by immunoprecipitation of (35) S-methionine-labeled cell extracts. Sera with which D, E, F, and G proteins of snRNP was immunoprecipitated, but without the other snRNP proteins, were further examined by analysis of RNA components by immunoprecipitation (silver staining), Western blotting using survival of motor neuron (SMN) complex, and immunofluorescence. RESULTS: Three sera that immunoprecipitated D, E, F, and G proteins without other components (U1-70K, A, B'/B, C) of the snRNP were found. Four additional proteins (130 kd, 120 kd, 38 kd, and 33 kd) were also commonly immunoprecipitated. The target antigen was identified as SMN complex (Gemin 3, Gemin 4, SMN, and Gemin 2, respectively), which plays a critical role in the assembly of snRNP. In immunofluorescence analyses, all 3 sera showed nuclear dots (Cajal bodies) and cytoplasmic staining. Only 1 serum was weakly positive on Western blotting of SMN, suggesting that these sera mainly recognize native molecule or quaternary structure. All 3 patients were white women with PM, an interesting finding, since deletion or mutation of SMN is known to cause spinal muscular atrophy. CONCLUSION: SMN complex was identified as a new Cajal body autoantigen recognized by sera from white patients with PM. The biologic and clinical significance of anti-SMN autoantibodies will need to be clarified.
OBJECTIVE: Autoantibodies in the systemic rheumatic diseases are clinically useful biomarkers of the diagnosis or of certain clinical characteristics. An unusual pattern of immunoprecipitation, in which the D, E, F, and G proteins of small nuclear RNPs (snRNP) but without other components of the snRNP, was noticed at the autoantibody screening. The purpose of this study was to examine the target antigens and clinical manifestations associated with this specificity. METHODS: Autoantibodies in sera from 1,966 American patients (including 434 with systemic lupus erythematosus, 121 with scleroderma, 86 with polymyositis/dermatomyositis [PM/DM]) and 248 Italian patients with autoimmune diseases were screened by immunoprecipitation of (35) S-methionine-labeled cell extracts. Sera with which D, E, F, and G proteins of snRNP was immunoprecipitated, but without the other snRNP proteins, were further examined by analysis of RNA components by immunoprecipitation (silver staining), Western blotting using survival of motor neuron (SMN) complex, and immunofluorescence. RESULTS: Three sera that immunoprecipitated D, E, F, and G proteins without other components (U1-70K, A, B'/B, C) of the snRNP were found. Four additional proteins (130 kd, 120 kd, 38 kd, and 33 kd) were also commonly immunoprecipitated. The target antigen was identified as SMN complex (Gemin 3, Gemin 4, SMN, and Gemin 2, respectively), which plays a critical role in the assembly of snRNP. In immunofluorescence analyses, all 3 sera showed nuclear dots (Cajal bodies) and cytoplasmic staining. Only 1 serum was weakly positive on Western blotting of SMN, suggesting that these sera mainly recognize native molecule or quaternary structure. All 3 patients were white women with PM, an interesting finding, since deletion or mutation of SMN is known to cause spinal muscular atrophy. CONCLUSION:SMN complex was identified as a new Cajal body autoantigen recognized by sera from white patients with PM. The biologic and clinical significance of anti-SMN autoantibodies will need to be clarified.
Authors: Yoshioki Yamasaki; Sonali Narain; Hideo Yoshida; Liza Hernandez; Tolga Barker; Paulette C Hahn; Eric S Sobel; Mark S Segal; Hanno B Richards; Edward K L Chan; Westley H Reeves; Minoru Satoh Journal: Arthritis Rheum Date: 2007-02
Authors: S Lefebvre; L Bürglen; S Reboullet; O Clermont; P Burlet; L Viollet; B Benichou; C Cruaud; P Millasseau; M Zeviani Journal: Cell Date: 1995-01-13 Impact factor: 41.582
Authors: Minoru Satoh; Shin Tanaka; Angela Ceribelli; S John Calise; Edward K L Chan Journal: Clin Rev Allergy Immunol Date: 2017-02 Impact factor: 8.667
Authors: Jan Damoiseaux; Luis Eduardo Coelho Andrade; Orlando Gabriel Carballo; Karsten Conrad; Paulo Luiz Carvalho Francescantonio; Marvin J Fritzler; Ignacio Garcia de la Torre; Manfred Herold; Werner Klotz; Wilson de Melo Cruvinel; Tsuneyo Mimori; Carlos von Muhlen; Minoru Satoh; Edward K Chan Journal: Ann Rheum Dis Date: 2019-03-12 Impact factor: 19.103
Authors: Edward K L Chan; Jan Damoiseaux; Orlando Gabriel Carballo; Karsten Conrad; Wilson de Melo Cruvinel; Paulo Luiz Carvalho Francescantonio; Marvin J Fritzler; Ignacio Garcia-De La Torre; Manfred Herold; Tsuneyo Mimori; Minoru Satoh; Carlos A von Mühlen; Luis E C Andrade Journal: Front Immunol Date: 2015-08-20 Impact factor: 7.561