Open AccessCharacterization of a phosphoprotein associated with the SS-B/La nuclear antigen in adenovirus-infected and uninfected KB cells.
Author(s) -
Lewis I. Pizer,
JauShyong Deng,
R M Stenberg,
Eng M. Tan
Publication year - 1983
Publication title -
molecular and cellular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.14
H-Index - 327
eISSN - 1067-8824
pISSN - 0270-7306
DOI - 10.1128/mcb.3.7.1235
Subject(s) - biology , phosphoprotein , antigen , phosphorylation , microbiology and biotechnology , antibody , virology , immune system , adenoviridae , virus , rna , cell nucleus , biochemistry , immunology , recombinant dna , gene
We have employed sera from patients with autoimmune disease to characterize the nuclear SS-B/La antigen in uninfected and adenovirus-infected KB cells. A 45,000-dalton phosphorylated polypeptide was specifically precipitated with anti-SS-B sera, and the level of phosphorylation was increased after infection. The increased phosphorylation appears to occur at the same amino acid residues phosphorylated in uninfected cells and results from increased phosphorylating activity rather than from altered enzyme specificity. A competition experiment between infected and uninfected cell extracts indicates that the antigen in the infected cell binds more strongly to SS-B/La antibodies. Fragments of adenovirus-induced virus-associated RNA as well as intact molecules complex with SS-B/La antigen and are immune precipitated with autoimmune sera.