Sp100 nuclear antigen

Autoantibodies directed against Sp100 are often found in patients with primary biliary cirrhosis.

This raises "the question whether cytokine-mediated increase of Sp100 protein expression plays a role in induction of anti-Sp100 autoantibodies.

These domains (few to 20) were found to form a donut-shaped structure when cells were starved of amino acids.

[5] Some Sp100 variants contain a domain similar to two interferon-inducible nuclear phosphoproteins, suppressin and DEAF1.

Another class of variants has high mobility group 1 (HMG1) protein sequence as a domain.