Skip Navigation

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Request Permissions
Google Scholar
Right arrow Articles by Sako, Y.
Right arrow Articles by Ohnishi, S.-i.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Sako, Y.
Right arrow Articles by Ohnishi, S.-i.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

J. Biochem, 1990, Vol. 107, No. 6 846-853
© 1990 Japanese Biochemical Society

research-article

Subpopulations of Endosomes Generated at Sequential Stages in the Endocytic Pathway of Asialoganglioside-Containing Ferrite Ligands in Rat Liver1

Yasushi Sako2, Satoshi B. Sato and Shun-ichi Ohnishi

Department of Biophysics, Faculty of Science, Kyoto University Sakyo-ku, Kyoto, Kyoto 606

2 To whom correspondence should be addressed at the present address: Department of Pure and Applied Sciences, College of Arts and Sciences, University of Tokyo, 3.8.1 Komaba, Meguro-ku, Tokyo 153.

Subpopulations of endosomes generated at different stages of the endocytic pathway were isolated by a high-gradient magnetic separation followed by a Percoll density gradient centrifugation. Rat livers were perfused for 5 min with asialoganglioside (ASG)-containing ferrite particles and chased at 37°C. At various times after the internal ization, the endocytic vesicles containing ferrite particles were isolated by the magnetic separation. Isolated fractions contained endosomes until 15-rain perfusion, after which most of the particles were transported to lysosomes. The endosomal fractions isolated after the 5- or 15-min perfusions were further analyzed by 30% Percoll density gradient centrifugation. The endosomes after 5-min perfusion showed peaks around the density of 1.05 g/ml (peak I) and 1.07 g/ml (peak Is), both of which contained asialoglycoprotein receptors. In the 15-min perfusion, another peak of endosomes (peak II) was observed at the higher density of 1.09 g/ml without the receptors, in addition to peak I. These endosomes had their own characteristic proteins. Some proteins were common in the subgroups of endosomes. These results suggest that the endosome I containing the ligands and the receptors was first produced after endocytosis and, through the endosome Is, was scissioned into the endosome II containing the ligands. The endosome II was then fused with primary lysosomes for proteolytic cleavage of ligands.

1This work was supported by a Grant-in-Aid from the Ministry of Education, Science and Culture of Japan.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.