A Practical Experimental Protocol for Identification and Validation of UFMylation Substrate in Human Cells

Area of Science:

• Biochemistry
• Molecular Biology
• Cellular Biology

Background:

• UFMylation is a vital ubiquitin-like modification regulating cellular homeostasis.
• Dysregulation of UFMylation is implicated in diseases like cancer and neurodegeneration.
• Limited knowledge of UFMylation substrates hinders understanding due to technical challenges.

Purpose of the Study:

• To develop an efficient and specific protocol for UFMylation detection.
• To enable large-scale identification of UFMylation substrates and modification sites.
• To overcome limitations of existing methods, including signal masking and low efficiency.

Main Methods:

• Utilized CRISPR-Cas9 gene editing to create UFSP1/UFSP2 double-knockout HEK293T cells.
• Employed exogenous introduction of mature UFM1-ΔC2 to enhance global UFMylation levels.
• Combined K-ε-VG antibody enrichment with LC-MS/MS for substrate identification.
• Verified UFMylation sites using site-directed mutagenesis and UFSP2-mediated de-UFMylation.

Main Results:

• Established a protocol that significantly elevates global protein UFMylation levels.
• Enabled high-efficiency enrichment and large-scale identification of UFMylation substrates.
• Successfully identified UFMylation sites on various substrates.
• Demonstrated the protocol's effectiveness in overcoming previous technical bottlenecks.

Conclusions:

• The developed protocol provides an effective tool for UFMylation substrate identification.
• This advancement facilitates deeper mechanistic understanding of UFMylation's role in health and disease.
• The method overcomes key technical limitations, paving the way for future research in the field.