A human autoimmune protein associated with U1 RNA contains a region of homology that is cross-reactive with retroviral p30gag antigen.

Abstract

cDNA encoding a 70 kd protein (70K) associated with U1 small nuclear ribonucleoprotein (snRNP) was cloned from a human brain-stem library using autoantibodies from patients with connective tissue disease. The cDNA-derived amino acid sequence contains 23 residues homologous to a region of murine leukemia virus group-specific antigen p30gag. The homology residues in an antigenic portion of the 70K protein and is defined by a core consensus sequence, ETPEEREERRR, that occurs as a tandem repeat in p30gag of most mammalian type C retroviruses. Anti-p30gag antibodies recognized a recombinant 70K-LacZ fusion protein as well as U1 snRNPs. Using synthetic peptides as competitors, we demonstrated that the region of homology encompasses the site of immunological cross-reactivity. Thus autoantibodies against U1 snRNPs were elicited by immunization with p30gag. On the basis of these findings, we suggest a role for retroviruses in the initiation of autoimmunity.

• Authors: C C Query, J D Keene
• Journal: Cell (Cell) Vol. 51 Issue 2 Pg. 211-20 (Oct 23 1987) ISSN: 0092-8674 [Print] United States
• PMID: 2959371 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Antibodies
• Antigens, Viral
• Autoantigens
• Immune Sera
• Ribonucleoproteins
• Ribonucleoproteins, Small Nuclear
• Viral Proteins
• DNA

Topics

• Antibodies (immunology)
• Antigens, Viral (immunology)
• Autoantigens (genetics, immunology)
• Autoimmune Diseases (blood)
• Base Sequence
• Cloning, Molecular
• Cross Reactions
• DNA (genetics)
• Genetic Code
• Humans
• Immune Sera (immunology)
• Molecular Sequence Data
• Moloney murine leukemia virus (metabolism)
• Retroviridae (immunology)
• Ribonucleoproteins (immunology)
• Ribonucleoproteins, Small Nuclear
• Sequence Homology, Nucleic Acid
• Viral Proteins (genetics)