Non-histone chromatin proteins of B lymphocytes stimulated by lipopolysaccharide. II. Phosphorylation.

Stott, D.I. and Williamson, A.R. (1978) Non-histone chromatin proteins of B lymphocytes stimulated by lipopolysaccharide. II. Phosphorylation. Biochimica et Biophysica Acta, 521(2), pp. 739-752.

Full text not currently available from Enlighten.

Abstract

Stimulation of mouse lymphocytes with the B lymphocyte specific mitogen lipopolysaccharide results in an increased rate of phosphorylation of non-histone chromatin proteins. An initial small increase in phosphorylation occurs during the first 2 h and a much larger increase after 24 h of culture with mitogen. The phosphorylated nuclear and cytoplasmic proteins were analysed by polyacrylamide gel electrophoresis and the stimulation index of each prominent peak measured. It was inferred that selective stimulation of the phosphorylation of individual proteins had occurred from: (1) the range of stimulation indices for different proteins, and (2) the appearance, after 8 h stimulation of an apparently newly phosphorylated non-histone chromatin protein of molecular weight 115 000. The pool size of ATP was monitored and showed only small changes during the first 24 h of exposure to lipopolysaccharide. Phosphatase activity was found to be associated with lymphocyte chromatin and nucleoplasm and may help to regulate the level of phosphorylation of non-histone chromatin proteins in vivo. To preserve phosphorylated proteins during their isolation phosphatase activity was inhibited by Na2MoO4. The selective changes in phosphorylation of nuclear proteins precede, and continue during, the stimulation of immunoglobulin and DNA synthesis. Our results are thus consistent with the hypothesis that phosphorylation of non-histone chromatin proteins plays a role in the regulation of gene expression in B lymphocytes.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Stott I, Professor David
Authors: Stott, D.I., and Williamson, A.R.
College/School:College of Medical Veterinary and Life Sciences > School of Infection & Immunity
Journal Name:Biochimica et Biophysica Acta
ISSN:0006-3002

University Staff: Request a correction | Enlighten Editors: Update this record