ARTICLE

SELECTIVE RELEASE OF CONTENT FROM MICROSOMAL VESICLES WITHOUT MEMBRANE DISASSEMBLY

Gert Kreibich ¹, Pascale Debey ¹, and David D. Sabatini ¹

¹ From The Rockefeller University, New York 10021 and New York University School of Medicine, New York 10016.

P. Debey's present address is Institut de Biologie Physico Chemique, Foundation de Rothschild, Paris 5e, France.

Rat liver rough microsomes treated with a series of desoxycholate (DOC) concentrations from 0.003 to 0.4% were analyzed by isopycnic sucrose density gradient centrifugation in media containing high or low salt concentrations. Tritium-labeled precursors administered in vivo were used as markers for ribosomes (orotic acid, 40 h), phospholipids (choline, 4 h), membrane proteins (leucine, 3 days), and completed secretory proteins of the vesicular cavity (leucine, 30 min). Within a narrow range of DOC concentrations (0.025–0.05%), the vesicular polypeptides were selectively released from the microsomes, while ribosomes, nascent polypeptides, and microsomal enzymes of the electron transport systems were unaffected. The detergent concentration which led to leakage of content was a function of the ionic strength and of the microsome concentration. At the lowest effective DOC concentration the microsomal membranes became reversibly permeable to macromoles as shown by changes in the density of the vesicles in Dextran gradients and by the extent of proteolysis by added proteases. Incubation of rough microsomes with proteases in the presence of 0.025% DOC also led to digestion of proteins from both faces of the microsomal membranes and to a lighter isopycnic density of the membrane vesicles.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Facebook    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

• Lamkin, M.S., Lindhe, P. (2001). Purification of Kinase Activity from Primate Parotid Glands. JDR 80: 1890-1894 [Abstract]  
• Barrieu, F., Chrispeels, M. J. (1999). Delivery of a Secreted Soluble Protein to the Vacuole via a Membrane Anchor. Plant Physiol. 120: 961-968 [Abstract] [Full Text]  
• Rustaeus, S., Stillemark, P., Lindberg, K., Gordon, D., Olofsson, S.-O. (1998). The Microsomal Triglyceride Transfer Protein Catalyzes the Post-translational Assembly of Apolipoprotein B-100 Very Low Density Lipoprotein in McA-RH7777 Cells. J. Biol. Chem. 273: 5196-5203 [Abstract] [Full Text]  
• Cluett, E., Machamer, C. (1996). The envelope of vaccinia virus reveals an unusual phospholipid in Golgi complex membranes. J. Cell Sci. 109: 2121-2131 [Abstract]  

Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents