42
Molecular and Cell Biology of Autoantibodies and Autoimmunity
Characterization of the snRNP Protein N: Description of a Potential
Sm Epitope
M. R. Lerner, G. McAllister, C. Schmauss, S. G. Amara, and A. Roby-Shemkovitz
Yale University, Section of Medical Neurobiology, School of Medicine, 333 Cedar Street,
New Haven, CT 06510, USA
N is a highly conserved, Sm-epitope bearing, snRNP-associated protein found
predominantly in brain. The amino acid sequences of N from humans and rats
are identical. N is closely related to, but distinct from, the major Sm epitope bear-
ing snRNP protein B (work of J. Hardin et al.). In particular, N lacks a con-
tinuous sequence of 50 amino acids present near the carboxy terminus of B.
Although the snRNP proteins B and B' are generally expressed in all human cells,
only N and B, but not B' are present in human brain. Polyclonal antibodies raised
against a 23 amino acid synthetic peptide based on part of the sequence of N
recognize A, N, B and B' on immunoblots. These antibodies can be used to im-
munoprecipitate the Sm class of U snRNAs from cell extracts.
Antigenic Structure of U snRNPS and Experimental Induction
of Anti-U snRNP Autoantibodies in Mice
R. Liihrmann
Institut fur Molekularbiologie und Tumorforschung der Philipps-Universitat,
Emil-Mannkopff-StraBe 2, D-3550 Marburg, FRG
Systemic lupus erythematosus (SLE) and related connective tissue diseases are
generalized autoimmune diseases characterized by the production of autoan-
tibodies against a variety of nuclear components. Among these are the anti-Sm
and anti-RNP antibodies, which react with the protein moiety of the small
nuclear RNPs containing the snRNAs U1, U2, U4, U5 and U6. Protein analyses
of the snRNPs led to the identification, besides the seven proteins B', B, D, D',
E, F and G common to these particles, of several particle-specific polypeptides.
Thus, U1 RNP possesses in addition the proteins 70 K, A and C: U2 contains the
proteins A' and B", and U 5 contains a number of unique proteins characterised
by apparent mol. wts. of 40, 52, 100, 102, 116 and 200 kDa. The latter particle,
is the biggest snRNP and sediments at 20 S.
Molecular and Cell Biology of Autoantibodies and Autoimmunity
Characterization of the snRNP Protein N: Description of a Potential
Sm Epitope
M. R. Lerner, G. McAllister, C. Schmauss, S. G. Amara, and A. Roby-Shemkovitz
Yale University, Section of Medical Neurobiology, School of Medicine, 333 Cedar Street,
New Haven, CT 06510, USA
N is a highly conserved, Sm-epitope bearing, snRNP-associated protein found
predominantly in brain. The amino acid sequences of N from humans and rats
are identical. N is closely related to, but distinct from, the major Sm epitope bear-
ing snRNP protein B (work of J. Hardin et al.). In particular, N lacks a con-
tinuous sequence of 50 amino acids present near the carboxy terminus of B.
Although the snRNP proteins B and B' are generally expressed in all human cells,
only N and B, but not B' are present in human brain. Polyclonal antibodies raised
against a 23 amino acid synthetic peptide based on part of the sequence of N
recognize A, N, B and B' on immunoblots. These antibodies can be used to im-
munoprecipitate the Sm class of U snRNAs from cell extracts.
Antigenic Structure of U snRNPS and Experimental Induction
of Anti-U snRNP Autoantibodies in Mice
R. Liihrmann
Institut fur Molekularbiologie und Tumorforschung der Philipps-Universitat,
Emil-Mannkopff-StraBe 2, D-3550 Marburg, FRG
Systemic lupus erythematosus (SLE) and related connective tissue diseases are
generalized autoimmune diseases characterized by the production of autoan-
tibodies against a variety of nuclear components. Among these are the anti-Sm
and anti-RNP antibodies, which react with the protein moiety of the small
nuclear RNPs containing the snRNAs U1, U2, U4, U5 and U6. Protein analyses
of the snRNPs led to the identification, besides the seven proteins B', B, D, D',
E, F and G common to these particles, of several particle-specific polypeptides.
Thus, U1 RNP possesses in addition the proteins 70 K, A and C: U2 contains the
proteins A' and B", and U 5 contains a number of unique proteins characterised
by apparent mol. wts. of 40, 52, 100, 102, 116 and 200 kDa. The latter particle,
is the biggest snRNP and sediments at 20 S.