Showing papers by "Eng M. Tan published in 1988"
TL;DR: A new antigen of 52 kD is defined which is another component of the SS-A particle and is associated in complex formation with the previously reported 60-kD protein.
Abstract: Anti-SS-A/Ro autoantibodies are found in the sera of patients with Sjogren's syndrome (SS) and SLE. In the course of analyzing 61 SS patients for their autoantibody profiles, we found that 42 were positive for anti-SS-A by double diffusion in agarose and demonstrated precipitin lines identical to that produced by a prototype anti-SS-A serum. Further analysis of these SS-A antibody-positive sera by Western blotting of cell extracts revealed that 21 sera reacted with two proteins of 60 and 52 kD, 13 sera reacted with 52-kD protein, two detected only 60 kD, while six were nonreactive. Affinity-purified anti-60-kD and anti-52-kD antibodies reacted exclusively with their corresponding antigens. Partial proteolysis of these proteins did not reveal common degradation fragments. Thus the 52- and 60-kD proteins were found to be antigenically and apparently structurally distinct from each other. They were also distinct from 48-kD SS-B/La protein. In immunoprecipitation using labeled cell extracts, affinity-purified anti-52-kD antibodies brought down the 52-kD protein as well as the 60-kD band. In [32P]orthophosphate-labeled HeLa cell extract both antibodies precipitated the same spectrum of small RNAs (hYl-5). In indirect immunofluorescence, anti-52-kD and anti-60-kD antibodies immunolocalized in similar subcellular structures and showed similar punctate nuclear staining patterns. Western blot analysis revealed that both proteins were present in lymphocytic as well as epithelial human cell lines tested. The data above define a new antigen of 52 kD which is another component of the SS-A particle and is associated in complex formation with the previously reported 60-kD protein.
372 citations
TL;DR: Antibodies against RNA polymerase I were associated with diffuse scleroderma of short duration, which was characterized by a high prevalence of internal organ involvement, including renal crisis, and anti-U3 RNP antibodies had ahigh prevalence in men with significantly less joint involvement, compared with ANoA-negative patients.
Abstract: Immunofluorescence on rat liver sections was used to select high-titer antinucleolar antibodies (ANoA) in the sera of patients with systemic sclerosis (scleroderma). In 646 patients, 53 ANoA sera (8%) were identified, and of these, 46 were available in sufficient quantities for further analysis. The complex of RNA polymerase I was immunoprecipitated by 7 sera (15%), which uniformly produced punctate nucleolar staining. The PM-Scl antigen, a particle consisting of 11 polypeptides, was immunoprecipitated by 8 sera (17%), all of which displayed homogeneous nucleolar staining. A 34-kd nucleolar protein (fibrillarin) of the U3 RNP complex was positive in immunoblotting of 22 sera (48%), which characteristically produced clumpy nucleolar staining. Antibodies against RNA polymerase I were associated with diffuse scleroderma of short duration, which was characterized by a high prevalence of internal organ involvement, including renal crisis. Anti-U3 RNP antibodies had a high prevalence in men with significantly less joint involvement, compared with ANoA-negative patients. Anti-PM-Scl antibodies identified a group of scleroderma patients with a high prevalence of concomitant myositis and renal involvement.
201 citations
TL;DR: The immunolocalization data suggest that 7-2-ribonucleoprotein may be involved in stages of ribosome biogenesis which take place in the granular component of the nucleolus, i.e., assembly, maturation, and/or transport of preribosomes.
105 citations
TL;DR: Findings related to the presence of autoantibodies to lamin proteins B, A, and C in a heterogeneous group of patients with thrombocytopen disease are described.
Abstract: Excerpt In this issue, Lassoued and colleagues (1) describe findings related to the presence of autoantibodies to lamin proteins B, A, and C in a heterogeneous group of patients with thrombocytopen...
13 citations