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Updated: May 29, 2026
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In Vitro Ubiquitination and Deubiquitination Assays of Nucleosomal Histones
Published on: July 25, 2019
Endosomal transport via ubiquitination
Robert C Piper1, Paul J Lehner
1Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA 52242, USA. Robert-Piper@uiowa.edu
Trends in Cell Biology
|September 30, 2011
Summary
Ubiquitin (Ub) tags damaged or downregulated cell-surface proteins for lysosomal degradation. This review explores how Ub governs protein trafficking and identifies remaining questions about this essential cellular process.
Area of Science:
- Cell Biology
- Molecular Biology
- Protein Trafficking
Background:
- Cellular homeostasis requires precise regulation of cell-surface membrane proteins.
- These proteins are internalized and degraded in lysosomes in response to cellular cues or damage.
- Ubiquitin (Ub) acts as a key signal for the lysosomal degradation pathway.
Purpose of the Study:
- To review the unifying mechanism of Ub-mediated protein trafficking to the lysosome.
- To highlight recent advances in understanding Ub-dependent protein sorting and degradation.
- To identify outstanding questions regarding Ub's role in protein homeostasis.
Main Methods:
- Literature review of recent research on protein trafficking and degradation.
- Analysis of the role of ubiquitin in clathrin-mediated endocytosis and lysosomal sorting.
- Discussion of regulatory mechanisms and protein-specific adaptations.
Main Results:
- Ubiquitin attachment is a conserved signal for the internalization and lysosomal degradation of damaged and downregulated cell-surface proteins.
- Clathrin-mediated endocytosis and sorting into late endosomes are key steps in Ub-dependent trafficking.
- The precise governance, protein-specific adaptations, and broader roles of Ub in protein fate remain active areas of investigation.
Conclusions:
- Ubiquitin plays a critical role in maintaining cell surface protein homeostasis by targeting proteins for lysosomal degradation.
- Further research is needed to fully elucidate the regulatory networks and diverse functions of Ub in protein trafficking.
- Understanding these pathways is crucial for comprehending cellular health and disease.
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