SPIN4 Is a Principal Endogenous Substrate of the E3 Ubiquitin Ligase DCAF16.
Xiaoyu ZhangMarvin ThielertHaoxin LiBenjamin F CravattPublished in: Biochemistry (2021)
DCAF16 is a substrate recognition component of Cullin-RING E3 ubiquitin ligases that can be targeted by electrophilic PROTACs (proteolysis targeting chimeras) to promote the nuclear-restricted degradation of proteins. The endogenous protein substates of DCAF16 remain unknown. In this study, we compared the protein content of DCAF16-wild type and DCAF16-knockout (KO) cells by untargeted mass spectrometry-based proteomics, identifying the Tudor domain-containing protein Spindlin-4 (SPIN4) as a protein with a level that was substantially increased in cells lacking DCAF16. Very few other proteomic changes were found in DCAF16-KO cells, pointing to a specific relationship between DCAF16 and SPIN4. Consistent with this hypothesis, we found that DCAF16 interacts with and ubiquitinates SPIN4, but not other related SPIN proteins, and identified a conserved lysine residue unique to SPIN4 that is involved in DCAF16 binding. Finally, we provide evidence that SPIN4 preferentially binds trimethylated histone H3K4 over other modified histone modifications. These results, taken together, indicate that DCAF16 and SPIN4 form a dedicated E3 ligase-substrate complex that regulates the turnover and presumed functions of SPIN4 in human cells.
Keyphrases
- room temperature
- density functional theory
- single molecule
- mass spectrometry
- induced apoptosis
- amino acid
- transition metal
- cell cycle arrest
- binding protein
- protein protein
- dna methylation
- molecular dynamics
- wild type
- cell proliferation
- endoplasmic reticulum stress
- liquid chromatography
- cancer therapy
- ionic liquid
- drug delivery
- capillary electrophoresis
- body composition
- gas chromatography mass spectrometry
- pi k akt
- simultaneous determination