Autoantibody reactive with the human general transcription factor TFIIF in sera from patients with autoimmune disorders

Abstract

SUMMARYTranscription factor (TF) IIF, a heteromeric protein composed of two subunits, RAP30 and RAP74, is required for both specific initiation and elongation of mRNA synthesis by RNA polymerase II. We have identified high titre of specific autoantibodies against the RAP74 subunit of TFIIF in sera from patients with systemic lupus erythematosus (SLE) as well as those with rheumatoid arthritis (RA), periarteritis nodosa (PN), Sjögren's syndrome (SS), dermatomyositis (DM), and mixed connective tissue disease (MCTD) by Western blot or immunoprecipitation. The epitopes recognized by autoantibodies were shown to be preferentially clustered at the central charged region. Anti-RAP74 autoantibody was shown to suppress the activity of TFIIF-stimulated elongation of mRNA synthesis by RNA polymerase II. It is concluded that some patients with autoimmune disorders develop specific autoantibodies against the RAP74 subunit of TFIIF.

Identification of known and novel genes in activated monocytes from patients with rheumatoid arthritis

“…Similar to transaldolase, the augmented expression of elongin may reflect increased de novo synthesis of RNA, which is necessary for the transcription of MO activation genes (50). A possible involvement in autoimmune processes can be envisaged also in this case, since autoantibodies against related molecules of the transcriptional machinery, i.e., RNA polymerase I and transcription factor IIF, have been detected in the serum and urine of patients with RA (51) and other autoimmune disorders (52,53).…”

Structure of the human transcription factor TFIIF revealed by limited proteolysis with trypsin

“…One mg/ml trypsin (Boehringer Mannheim) was prepared in 1 mM HCl and used after appropriate dilution. The conditions of Western blotting, including electro-transfer to a nitrocellulose membrane, blocking, and detection with chemiluminescent reagent CSPD, were as described [26]. Antibodies against full length RAP74 or RAP30 were prepared as described previously [11], anti-RAP74 (N-16) or anti-RAP74 (C-18) antibodies against the N-terminal 43^58 or C-terminal 498^515 amino acids of RAP74, respectively, were obtained from Santa-Cruze.…”