1. Intracellular Context Affects Levels of a Chemically Dependent Destabilizing Domain
- Author
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Mark A. Sellmyer, Ling-chun Chen, Emily Egeler, Thomas J. Wandless, and Rishi Rakhit
- Subjects
Intracellular Space ,lcsh:Medicine ,Endoplasmic Reticulum ,Biochemistry ,0302 clinical medicine ,Protein structure ,Molecular Cell Biology ,Protein biosynthesis ,Biomacromolecule-Ligand Interactions ,lcsh:Science ,Cellular Stress Responses ,0303 health sciences ,Multidisciplinary ,Protein Stability ,Tunicamycin ,Systems Biology ,Cellular Structures ,Mitochondria ,Transport protein ,Cell biology ,DNA-Binding Proteins ,Protein Transport ,Chemistry ,Medicine ,Membranes and Sorting ,Synthetic Biology ,Research Article ,Drugs and Devices ,RNA Splicing ,Recombinant Fusion Proteins ,Regulatory Factor X Transcription Factors ,Biology ,DNA-binding protein ,03 medical and health sciences ,Chemical Biology ,Humans ,Transcription factor ,030304 developmental biology ,Cell Nucleus ,Endoplasmic reticulum ,lcsh:R ,Proteins ,Molecular biology ,Protein Structure, Tertiary ,HEK293 Cells ,Subcellular Organelles ,Small Molecules ,Cytoplasm ,Unfolded Protein Response ,Unfolded protein response ,lcsh:Q ,030217 neurology & neurosurgery ,Transcription Factors - Abstract
The ability to regulate protein levels in live cells is crucial to understanding protein function. In the interest of advancing the tool set for protein perturbation, we developed a protein destabilizing domain (DD) that can confer its instability to a fused protein of interest. This destabilization and consequent degradation can be rescued in a reversible and dose-dependent manner with the addition of a small molecule that is specific for the DD, Shield-1. Proteins encounter different local protein quality control (QC) machinery when targeted to cellular compartments such as the mitochondrial matrix or endoplasmic reticulum (ER). These varied environments could have profound effects on the levels and regulation of the cytoplasmically derived DD. Here we show that DD fusions in the cytoplasm or nucleus can be efficiently degraded in mammalian cells; however, targeting fusions to the mitochondrial matrix or ER lumen leads to accumulation even in the absence of Shield-1. Additionally, we characterize the behavior of the DD with perturbants that modulate protein production, degradation, and local protein QC machinery. Chemical induction of the unfolded protein response in the ER results in decreased levels of an ER-targeted DD indicating the sensitivity of the DD to the degradation environment. These data reinforce that DD is an effective tool for protein perturbation, show that the local QC machinery affects levels of the DD, and suggest that the DD may be a useful probe for monitoring protein quality control machinery.
- Published
- 2012
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