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Updated: May 6, 2026

Studying Protein Import into Chloroplasts Using Protoplasts
Published on: December 10, 2018
Different routes for integral protein insertion into Ricinus communis protein-body and glyoxysome membranes
C Halpin1, M J Conder, J M Lord
1Department of Biological Sciences, University of Warwick, CV4 7AL, Coventry, UK.
Abstract:
Total polyadenylated RNA from ripening or germinating Ricinus communis L. endosperm was translated in rabbit reticulocyte lysate in the absence or presence of canine pancreatic microsomes. The products were immunoprecipitated using antibodies raised againts Triton X-114-extracted integral membrane proteins of protein bodies or glyoxysomes. While the proteins of proteinbody membranes were found to insert co-translationally into added microsomes, this was not observed in the case of glyoxysomal proteins. This observation was confirmed using antibodies raised against a purified glyoxysome membrane protein, alkaline lipase. These results indicate that different routes exist for the insertion of membrane proteins into the two organelles. In both cases membrane-protein insertion does not appear to be accompanied by proteolytic processing.
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