DOI Page / Citation link:
https://doi.org/10.11588/diglit.48120#0062
44 Molecular and Cell Biology of Autoantibodies and Autoimmunity
The U1 RNBA Binding Site of the U1 snRNP-Associated A Protein
Overlaps an Anti-Ul RNA Antibody Binding Site
C. Lutz-Freyermuth and J. D. Keene
Department of Microbiology and Immunology, Duke University Medical Center, Durham,
NC 27710, USA
The U snRNPs are small nuclear ribonucleoprotein complexes that are known
to be involved in the processing of precursor mRNAs to the mature form. Each
snRNP is composed of both proteins unique to that snRNP as well as proteins
common to all snRNPs. Some autoimmune patients make antibodies against
these proteins, providing useful reagents to study the snRNPs. The precise prote-
in-RNA and protein-protein interactions that exist in each snRNP are largely un-
known.
A protein
antibody 1
step 1
step 3
proposed model for origin of anti-UI RNA antibodies
We have previously described a unique human anti-RNA autoantibody found
in patients with lupus overlap syndrome and rheumatoid arthritis (Deutscher
and Keene, 1988, PNAS USA 85:3299-3303). The recognition site of this an-
tibody on U 1 RNA may overlap a binding site for another U1 RNA-associated
protein. We propose that the anti-U 1 RNA autoantibody is anti-idiotypic to an
antibody directed against an RNA-binding domain of a U1-associated protein.
Thus, it is likely that the anti-U 1 RNA antibody was formed against the original
autoantibody rather than by direct presentation of the naked U 1 RNA to the im-
mune system. Lymphocytes from the patient with this unique reactivity were
isolated, immortalized with EBV, and were screened for the production of anti-
U1 RNA antibodies that were devoid of any other reactivity. Antibodies with
specificity to the second stem-loop structure of U 1 RNA have been produced in
this manner in order to address the origin of the antibody as an anti-idiotype.
The U1 RNBA Binding Site of the U1 snRNP-Associated A Protein
Overlaps an Anti-Ul RNA Antibody Binding Site
C. Lutz-Freyermuth and J. D. Keene
Department of Microbiology and Immunology, Duke University Medical Center, Durham,
NC 27710, USA
The U snRNPs are small nuclear ribonucleoprotein complexes that are known
to be involved in the processing of precursor mRNAs to the mature form. Each
snRNP is composed of both proteins unique to that snRNP as well as proteins
common to all snRNPs. Some autoimmune patients make antibodies against
these proteins, providing useful reagents to study the snRNPs. The precise prote-
in-RNA and protein-protein interactions that exist in each snRNP are largely un-
known.
A protein
antibody 1
step 1
step 3
proposed model for origin of anti-UI RNA antibodies
We have previously described a unique human anti-RNA autoantibody found
in patients with lupus overlap syndrome and rheumatoid arthritis (Deutscher
and Keene, 1988, PNAS USA 85:3299-3303). The recognition site of this an-
tibody on U 1 RNA may overlap a binding site for another U1 RNA-associated
protein. We propose that the anti-U 1 RNA autoantibody is anti-idiotypic to an
antibody directed against an RNA-binding domain of a U1-associated protein.
Thus, it is likely that the anti-U 1 RNA antibody was formed against the original
autoantibody rather than by direct presentation of the naked U 1 RNA to the im-
mune system. Lymphocytes from the patient with this unique reactivity were
isolated, immortalized with EBV, and were screened for the production of anti-
U1 RNA antibodies that were devoid of any other reactivity. Antibodies with
specificity to the second stem-loop structure of U 1 RNA have been produced in
this manner in order to address the origin of the antibody as an anti-idiotype.