The cell proliferation-associated protein Ki-67 is a target of autoantibodies in the serum of MRL mice.

Background: Ab in the serum of patients with autoimmune diseases have been used to identify, characterize, and purify many autoantigens.

Experimental Design: Serum from a patient (Ge) with Sjögren's syndrome was used to identify cDNA clones encoding novel autoantigens. This patient's serum was chosen for study because it contained antinuclear Ab that were different from those frequently detected in patients with autoimmune diseases.

Constitutive endothelial nitric oxide synthase gene expression is regulated during lung development.

Nitric oxide (NO), a potent vasodilator, is a free-radical gas synthesized from L-arginine by nitric oxide synthases (NOS). NO appears to have an important role in perinatal changes in pulmonary vascular resistance. We previously identified mRNA encoding the constitutive endothelial NOS (ceNOS) isoform in human pulmonary tissue.

The immunoreactive region in a novel autoantigen contains a nuclear localization sequence.

Antibodies in the serum of patients with autoimmune diseases have been used to identify human autoantigens. Because autoantibodies often recognize active sites within corresponding protein antigens, autoantibodies have facilitated the functional characterization of these polypeptides. In the present study, serum from a patient with Sjögren's syndrome was used to identify a novel autoantigen which was designated Ge-1.