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Localization of SUMO-modified Proteins Using Fluorescent Sumo-trapping Proteins
Published on: April 27, 2019
Essential role of nuclear localization for yeast Ulp2 SUMO protease function
Mary B Kroetz1, Dan Su, Mark Hochstrasser
1Department of Cell Biology, Yale University, New Haven, CT 06520-8114, USA.
Molecular Biology of the Cell
|February 20, 2009
Summary
The SUMO protease Ulp2
Area of Science:
- Cell Biology
- Biochemistry
- Molecular Biology
Background:
- SUMOylation is a reversible post-translational modification crucial for cellular processes.
- SUMO proteases, like yeast Ulp2 and human SENP6, regulate SUMOylation.
- Ulp2 is vital for chromosome stability and cell cycle progression in yeast.
Purpose of the Study:
- To investigate the functional roles of Ulp2's N-terminal domain (NTD) and C-terminal domain (CTD).
- To determine the requirements for Ulp2's nuclear localization and function.
- To understand the structural basis for the poor conservation of NTDs in the Ulp2/SENP6 family.
Main Methods:
- Deletion mutagenesis of Ulp2's CTD and NTD.
- Analysis of poly-SUMO conjugate accumulation.
- Assessment of nuclear import using beta-importin Kap95.
- Functional complementation assays with a heterologous NLS.
Main Results:
- CTD deletion moderately impacts yeast growth but increases poly-SUMO conjugates.
- The NTD is essential for Ulp2 function and nuclear targeting.
- Specific short sequences within the NTD mediate nuclear localization.
- Replacing the NTD with a heterologous NLS largely restores Ulp2 function.
Conclusions:
- Nuclear localization of Ulp2 is critical for its in vivo function.
- Minimal regions within the NTD are sufficient for nuclear import.
- This explains the limited sequence conservation observed in the NTDs of Ulp2/SENP6 family proteases.
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