Target protein localization and its impact on PROTAC-mediated degradation

Area of Science:

• Biochemistry
• Molecular Biology
• Cell Biology

Background:

• Proteolysis-targeting chimeras (PROTACs) are heterobifunctional molecules that induce degradation of target proteins.
• PROTACs function by recruiting an E3 ubiquitin ligase to a protein of interest (POI), leading to ubiquitylation and proteasomal degradation.
• The efficacy of PROTACs may be influenced by the subcellular localization of the POI and the accessibility of the recruited E3 ligase.

Purpose of the Study:

• To investigate whether the subcellular context of a protein of interest affects PROTAC-mediated degradation.
• To determine if varying POI localization impacts the efficiency of degradation by different PROTACs.

Main Methods:

• Engineered Halo or FKBP12^F36V (dTAG) fusion proteins with various subcellular localization signals.
• Expressed these constructs in cells and treated with von Hippel-Lindau (VHL)- or cereblon (CRBN)-recruiting PROTACs targeting Halo or dTAG.
• Assessed degradation levels of the localized POIs using the respective PROTACs.

Main Results:

• Proteins of interest localized to different subcellular compartments (nucleus, cytoplasm, mitochondria, ER, Golgi, peroxisome, lysosome) exhibited varying degradation levels when treated with the same PROTACs.
• The efficacy of PROTAC-mediated degradation was dependent on the specific subcellular location of the targeted protein.

Conclusions:

• Subcellular localization is a critical determinant of PROTAC efficacy.
• The spatial context of a protein influences its susceptibility to PROTAC-induced degradation, highlighting the importance of cellular architecture in PROTAC design and application.