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

Charles C. Query, Jack D. Keene

Research output: Contribution to journalArticle

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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 resides 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.

Original languageEnglish (US)
Pages (from-to)211-220
Number of pages10
Issue number2
StatePublished - Oct 23 1987
Externally publishedYes


ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

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