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In Vitro Ubiquitination and Deubiquitination Assays of Nucleosomal Histones
Published on: July 25, 2019
Ubiquitylation as a quality control system for intracellular proteins
Shigetsugu Hatakeyama1, Keiichi I Nakayama
1Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka. hatas@bioreg.kyushu-u.ac.jp
Journal of Biochemistry
|August 29, 2003
Summary
Cellular protein quality control relies on chaperones and the ubiquitin-proteasome system. This review highlights U-box proteins as a new class of E3 ligases crucial for protein homeostasis and cell survival.
Area of Science:
- Molecular Biology
- Cell Biology
- Biochemistry
Background:
- Cellular homeostasis depends on stringent quality control of intracellular proteins.
- Molecular chaperones assist in refolding, while the ubiquitin-proteasome system degrades misfolded proteins.
- Ubiquitin-protein ligases (E3s) dictate substrate specificity in ubiquitylation, traditionally classified into HECT and RING-finger families.
Purpose of the Study:
- To review recent advancements in understanding the role of E3 enzymes in intracellular protein quality control.
- To focus on the emerging class of U-box proteins as critical E3 ligases.
- To explore the functional implications of U-box proteins in cellular processes.
Main Methods:
- Literature review of recent research on E3 enzymes and protein quality control.
- Analysis of studies characterizing U-box domain proteins and their mechanisms.
- Examination of functional studies, including those involving yeast Ufd2.
Main Results:
- U-box proteins represent a newly identified family of E3 ubiquitin ligases.
- These proteins contain a conserved U-box domain crucial for their function.
- Yeast Ufd2, a U-box protein, acts as a ubiquitin chain assembly factor (E4) and is vital for cell survival under stress.
Conclusions:
- U-box proteins are significant players in the ubiquitin-proteasome system's quality control pathway.
- Their unique domain structure and function expand the known repertoire of E3 ligases.
- Further research into U-box proteins offers insights into maintaining cellular protein homeostasis and stress resilience.
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These groups modify specific amino acids in a protein.
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