Characteristics of Membrane Protein Phosphorylation in Plasmodium berghei‐Infected Mouse Erythrocytes

Abstract

ABSTRACT. Membrane protein phosphorylation in Plasmodium berghei‐infected erythrocytes was studied by incubating intact cells with ( 32 P)orthophosphate and incubating isolated membrane with (γ‐ 32 P)ATP. Phosphorylated proteins were detected by autoradiography after sodium dodecylsulfate (SDS)‐polyacrylamide gel electrophoresis or isoelectric focusing followed by gel electrophoresis. New phosphorylated proteins were found in membrane from infected erythrocytes, including a protein with electrophoretic mobility identical to band 5, with M, 43,000. The molar ratio of phosphate to protein ranged between 0.1 and 0.5. Isoelectric focusing‐SDS polyacrylamide gel electrophoresis, peptide mapping, extractability properties, and reduction of susceptibility to DNase I inhibition suggested that this protein is phosphorylated actin. In contrast, spectrin phosphorylation in infected erythrocytes was mostly unchanged. Copyright © 1986, Wiley Blackwell. All rights reserved