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Sphingomyelinase Treatment Induces ATP-independent Endocytosis
ATP hydrolysis has been regarded as a general requirement for internalization processes in mammalian cells. We found, however, that treatment of ATP-depleted macrophages and fibroblasts with exogenous sphingomyelinase (SMase) rapidly induces formation of numerous vesicles that pinch off from the pla...
Autores principales: | , , , , , |
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Formato: | Texto |
Lenguaje: | English |
Publicado: |
The Rockefeller University Press
1998
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2132600/ https://www.ncbi.nlm.nih.gov/pubmed/9425152 |
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author | Zha, Xiaohui Pierini, Lynda M. Leopold, Philip L. Skiba, Paul J. Tabas, Ira Maxfield, Frederick R. |
author_facet | Zha, Xiaohui Pierini, Lynda M. Leopold, Philip L. Skiba, Paul J. Tabas, Ira Maxfield, Frederick R. |
author_sort | Zha, Xiaohui |
collection | PubMed |
description | ATP hydrolysis has been regarded as a general requirement for internalization processes in mammalian cells. We found, however, that treatment of ATP-depleted macrophages and fibroblasts with exogenous sphingomyelinase (SMase) rapidly induces formation of numerous vesicles that pinch off from the plasma membrane; the process is complete within 10 min after adding SMase. By electron microscopy, the SMase-induced vesicles are ∼400 nm in diameter and lack discernible coats. 15–30% of plasma membrane is internalized by SMase treatment, and there is no detectable enrichment of either clathrin or caveolin in these vesicles. When ATP is restored to the cells, the SMase-induced vesicles are able to deliver fluid-phase markers to late endosomes/lysosomes and return recycling receptors, such as transferrin receptors, back to the plasma membrane. We speculate that hydrolysis of sphingomyelin on the plasma membrane causes inward curvature and subsequent fusion to form sealed vesicles. Many cell types express a SMase that can be secreted or delivered to endosomes and lysosomes. The hydrolysis of sphingomyelin by these enzymes is activated by several signaling pathways, and this may lead to formation of vesicles by the process described here. |
format | Text |
id | pubmed-2132600 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 1998 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-21326002008-05-01 Sphingomyelinase Treatment Induces ATP-independent Endocytosis Zha, Xiaohui Pierini, Lynda M. Leopold, Philip L. Skiba, Paul J. Tabas, Ira Maxfield, Frederick R. J Cell Biol Article ATP hydrolysis has been regarded as a general requirement for internalization processes in mammalian cells. We found, however, that treatment of ATP-depleted macrophages and fibroblasts with exogenous sphingomyelinase (SMase) rapidly induces formation of numerous vesicles that pinch off from the plasma membrane; the process is complete within 10 min after adding SMase. By electron microscopy, the SMase-induced vesicles are ∼400 nm in diameter and lack discernible coats. 15–30% of plasma membrane is internalized by SMase treatment, and there is no detectable enrichment of either clathrin or caveolin in these vesicles. When ATP is restored to the cells, the SMase-induced vesicles are able to deliver fluid-phase markers to late endosomes/lysosomes and return recycling receptors, such as transferrin receptors, back to the plasma membrane. We speculate that hydrolysis of sphingomyelin on the plasma membrane causes inward curvature and subsequent fusion to form sealed vesicles. Many cell types express a SMase that can be secreted or delivered to endosomes and lysosomes. The hydrolysis of sphingomyelin by these enzymes is activated by several signaling pathways, and this may lead to formation of vesicles by the process described here. The Rockefeller University Press 1998-01-12 /pmc/articles/PMC2132600/ /pubmed/9425152 Text en This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/). |
spellingShingle | Article Zha, Xiaohui Pierini, Lynda M. Leopold, Philip L. Skiba, Paul J. Tabas, Ira Maxfield, Frederick R. Sphingomyelinase Treatment Induces ATP-independent Endocytosis |
title | Sphingomyelinase Treatment Induces ATP-independent Endocytosis |
title_full | Sphingomyelinase Treatment Induces ATP-independent Endocytosis |
title_fullStr | Sphingomyelinase Treatment Induces ATP-independent Endocytosis |
title_full_unstemmed | Sphingomyelinase Treatment Induces ATP-independent Endocytosis |
title_short | Sphingomyelinase Treatment Induces ATP-independent Endocytosis |
title_sort | sphingomyelinase treatment induces atp-independent endocytosis |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2132600/ https://www.ncbi.nlm.nih.gov/pubmed/9425152 |
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