RNA Pol IIIA

Product Information

Systemic sclerosis (SSc), also known as scleroderma, is a complex and multi-system autoimmune disease. SSc has clinical features that are characterised by functional and structural abnormalities of small blood vessels, fibrosis of skin and internal organs, and production of autoantibodies.

A variety of systemic sclerosis (SSc)-related circulating antinuclear antibodies (ANA) have been well-characterized, these encompass the anti-centromere, anti-topoisomerase I (Scl-70), PM-Scl 100, and anti-RNA polymerase (RNA Pol) III antibody and are used in daily clinical practice. The prevalence of RNA Pol III autoantibodies was found to be one of the highest in certain patient cohorts diagnosed with SSc. The anti-RNAPol III antibody biomarker is highly specific to SSc and is associated with diffuse cutaneous SSc (dcSSc) and scleroderma renal crisis (SRC).

RNA Pol IIIA, also known as subunit RPC1 of DNA-directed RNA Polymerase III and RNA Polymerase III 155 kDa subunit, is part of 17 protein subunits of the human RNA Polymerase III complex. Its role is the synthesis of tRNA and other short essential RNAs. RNA Pol IIIA has been identified as an antigenic protein that is recognized by SSc sera.

AROTEC RNA Pol IIIA antigen is a truncated construct of the full-length RNA Pol IIIA. It is expressed in E. coli, with a hexa-histidine tag and contains the antigenic epitope as identified by Kuwana et al., 2002. This immunodominant epitope was mapped using a series of recombinant fragments (expressed in Escherichia coli) probed against SSc diagnosed patient sera. The nature of this epitope proved to be linear.

Clinical Indications

Systemic sclerosis

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MSDS

References

Burbelo, P. D., Gordon, S. M., Waldman, M., Edison, J. D., Little, D. J., Stitt, R. S., Bailey, W. T., Hughes, J. B., & Olson, S. W. (2019). Autoantibodies are present before the clinical diagnosis of systemic sclerosis. PLoS ONE, 14(3).

Elhannani, A., Martel, M. E., Collet, A., Chepy, A., Sanges, S., Hachulla, É., Dubucquoi, S., Launay, D., & Sobanski, V. (2025). Anti-RNA polymerase III antibodies in systemic sclerosis: prevalence and clinical associations from a systematic review and meta-analysis. Rheumatology, 64(12), 6023–6035.

Girbig, M., Misiaszek, A. D., Vorländer, M. K., Lafita, A., Grötsch, H., Baudin, F., Bateman, A., & Müller, C. W. (2021). Cryo-EM structures of human RNA polymerase III in its unbound and transcribing states. Nature Structural and Molecular Biology, 28(2), 210–219.

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Kuwana, M., Kaburaki, J., Mimori, T., Tojo, T., & Homma, M. (1993). Autoantibody Reactive with Three Classes of RNA Polymerases in Sera from Patients with Systemic Sclerosis immunoprecipitation-in vitro transcription assay subunit autoimmunity-nuclear enzyme. In J. Clin. Invest (Vol. 91).

Kuwana, M., Kimura, K., & Kawakami, Y. (2002). Identification of an immunodominant epitope on RNA polymerase III recognized by systemic sclerosis sera: Application to enzyme-linked immunosorbent assay. Arthritis and Rheumatism, 46(10), 2742–2747. https://doi.org/10.1002/art.10521

Kuwana, M., Okano, Y., Kaburaki, J., Medsger, T. A. Jr., & Wright, T. M. (1999). Autoantibodies to RNA polymerases recognize multiple subunits and demonstrate cross-reactivity with RNA polymerase complexes. Arthritis & Rheumatism, 42, 275–284.

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Sobanski, V., Dauchet, L., Lefèvre, G., Lambert, M., Morell-Dubois, S., Sy, T., Hachulla, E., Hatron, P.-Y., Launay, D., & Dubucquoi, S. (2014). Prevalence of Anti–RNA Polymerase III Antibodies in Systemic Sclerosis: New Data From a French Cohort and a Systematic Review and Meta-Analysis. Arthritis and Rheumatology, 66(2), 407–417.

van den Hoogen F, Khanna D, Fransen J, et al. 2013 classification criteria for systemic sclerosis: an American college of rheumatology/European league against rheumatism collaborative initiative. Annals of the Rheumatic Diseases 2013; 72:1747-1755.

Volkmann, E. R., Andréasson, K., & Smith, V. (2023). Systemic sclerosis. The Lancet, 401(10373), 304–318.