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Published on: March 3, 2015
Identification of a functional nuclear translocation sequence in hPPIP5K2
Sheila T Yong1, Hoai-Nghia Nguyen2, Jae H Choi3,4
1Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, 101 T.W. Alexander Drive, Research Triangle Park, NC, 27709, USA. yongst.work@gmail.com.
Nuclear localization of the enzyme hPPIP5K2 is functionally significant and regulated by phosphorylation. This study reveals how the enzyme
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Inositol pyrophosphates (PP-InsPs) are crucial for cellular homeostasis.
- Understanding PP-InsP synthesis compartmentation is key to their function.
- Human PPIP5K2 (hPPIP5K2) synthesizes PP-InsPs and has a putative nuclear localization signal (NLS).
Purpose of the Study:
- Investigate the functionality and regulation of the hPPIP5K2 NLS.
- Determine the nuclear localization of hPPIP5K2.
- Explore the role of phosphorylation in regulating hPPIP5K2 nuclear import.
Main Methods:
- Cell biology techniques
- Mutagenesis
- Mass spectrometry
- Confocal microscopy
- Imaging flow cytometry
Main Results:
- A conserved NLS exists in the metazoan PPIP5K2 family.
- hPPIP5K2 is present in the nucleus of HEK293T cells.
- Disrupting the NLS reduced nuclear localization.
- Phosphorylation of Ser1006 regulates hPPIP5K2 nuclear import.
Conclusions:
- The NLS in PPIP5K2 is functional and conserved.
- Nuclear compartmentation of hPPIP5K2 is physiologically relevant and regulated by covalent modification.
- Phosphorylation of Ser1006 dynamically controls hPPIP5K2 nuclear localization.
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