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Ubpy controls the stability of the ESCRT-0 subunit Hrs in development
Junzheng Zhang1, Juan Du, Cong Lei
1State Key Laboratory of Biomembrane and Membrane Biotechnology, Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, Peking-Tsinghua Center for Life Sciences, College of Life Sciences, Peking University, Beijing 100871, China.
Development (Cambridge, England)
|February 28, 2014
Summary
Ubiquitin isopeptidase Y (Ubpy) maintains endosomal sorting complex (ESCRT) stability by deubiquitylating Hrs. Loss of Ubpy leads to signaling protein accumulation in enlarged endosomes due to ESCRT defects.
Area of Science:
- Cell biology
- Molecular biology
- Developmental biology
Background:
- Ubiquitylated proteins are internalized via endocytosis for lysosomal degradation.
- Endosomal Sorting Complexes Required for Transport (ESCRT) mediate this process.
- Regulation of the ESCRT machinery itself remains incompletely understood.
Purpose of the Study:
- To investigate the role of Ubiquitin isopeptidase Y (Ubpy) in ESCRT regulation.
- To elucidate the mechanism by which Ubpy influences endocytic trafficking and protein homeostasis.
Main Methods:
- Utilized Drosophila melanogaster as a model organism.
- Investigated phenotypes in Ubpy-null mutants.
- Performed co-immunoprecipitation and deubiquitylation assays.
- Analyzed endosomal morphology and protein localization.
Main Results:
- Absence of Drosophila Ubpy causes accumulation of signaling proteins in enlarged endosomes.
- Ubpy interacts with and deubiquitylates Hrs, an ESCRT-0 component.
- Loss of Ubpy leads to Hrs ubiquitylation and lysosomal degradation, disrupting ESCRT integrity.
- Abolishing Hrs activity results in signaling protein enrichment in enlarged endosomes.
Conclusions:
- Ubpy plays a crucial role in maintaining ESCRT-0 complex stability.
- Ubpy acts dually in cargo deubiquitylation and ESCRT-0 homeostasis during development.
- Dysregulation of Ubpy impacts endocytic trafficking and signaling protein localization.
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