DOI Seite / Zitierlink:
https://doi.org/10.11588/diglit.48120#0048
30 Molecular and Cell Biology of Autoantibodies and Autoimmunity
Our investigations also extend to the class of snRNP which are associated with
the Ro and La antigens that are characteristic of the disease Sjogren’s syndrome.
Particular emphasis has been placed on the Ro antigen. Ro is present in the cell
as part of an RNP complex whose RNA components are designated Y RNAs.
Despite the cytoplasmic localization of the Y RNAs and, therefore, by inference
of the Ro protein, there is conflicting data suggesting both nuclear and cyto-
plasmic localization for Ro. The actual function of the Ro RNP remains obscure;
possible involvement in translation and in mRNA transport and storage has been
hypothesized. With the aim to determine the molecular structure of the Ro
polypeptide(s), we decided to clone the cDNA encoding at least one of the Ro an-
tigens. The approach was the same as for the Sm antigens, but in this case we
designed an oligonucleotide probe based on a published-amino-terminal se-
quences for a 60000 m.w. Ro species (3). Positive clones were identified and se-
quenced. One such clone, designated 38-1, has a codon composition exactly mat-
ching that of the published Ro sequence. In addition, analysis of the deduced se-
quence with that of the mature protein reveals the presence of a putative 17-amino
acid long signal peptide with a canonical alanine residue at its proposed process-
ing site. This raises interesting questions regarding the function and compartmen-
talization of Ro. The carboxy-terminal part of the predicted Ro amino acid se-
quence is very rich in charged residues, particularly acidic ones, which may have
relevance to Ro as an autoantigen.
References
1. Rokeach, L.A., Haselby, J. A., Hoch, S. O. (1988): Proc. Natl. Acad. Sci. USA 85,
4832
2. Rokeach, L.A., Jannatipour, M., Haselby, J. A., Hoch, S.O. (1989): J. Biol.
Chem. 264, 5024
3. Lieu, T.-S., Newkirk, M.M., Capra, J.D., Sontheimer, R. D. (1988): J. Clin. Invest.
82, 96
Our investigations also extend to the class of snRNP which are associated with
the Ro and La antigens that are characteristic of the disease Sjogren’s syndrome.
Particular emphasis has been placed on the Ro antigen. Ro is present in the cell
as part of an RNP complex whose RNA components are designated Y RNAs.
Despite the cytoplasmic localization of the Y RNAs and, therefore, by inference
of the Ro protein, there is conflicting data suggesting both nuclear and cyto-
plasmic localization for Ro. The actual function of the Ro RNP remains obscure;
possible involvement in translation and in mRNA transport and storage has been
hypothesized. With the aim to determine the molecular structure of the Ro
polypeptide(s), we decided to clone the cDNA encoding at least one of the Ro an-
tigens. The approach was the same as for the Sm antigens, but in this case we
designed an oligonucleotide probe based on a published-amino-terminal se-
quences for a 60000 m.w. Ro species (3). Positive clones were identified and se-
quenced. One such clone, designated 38-1, has a codon composition exactly mat-
ching that of the published Ro sequence. In addition, analysis of the deduced se-
quence with that of the mature protein reveals the presence of a putative 17-amino
acid long signal peptide with a canonical alanine residue at its proposed process-
ing site. This raises interesting questions regarding the function and compartmen-
talization of Ro. The carboxy-terminal part of the predicted Ro amino acid se-
quence is very rich in charged residues, particularly acidic ones, which may have
relevance to Ro as an autoantigen.
References
1. Rokeach, L.A., Haselby, J. A., Hoch, S. O. (1988): Proc. Natl. Acad. Sci. USA 85,
4832
2. Rokeach, L.A., Jannatipour, M., Haselby, J. A., Hoch, S.O. (1989): J. Biol.
Chem. 264, 5024
3. Lieu, T.-S., Newkirk, M.M., Capra, J.D., Sontheimer, R. D. (1988): J. Clin. Invest.
82, 96