Photoactivatable Myristic Acid Probes for UNC119-Cargo Interactions

Area of Science:

• Biochemistry
• Molecular Biology
• Chemical Biology

Background:

• Protein myristoylation is crucial for cellular functions like membrane attachment and protein activation.
• Myristoylated proteins are implicated in diseases such as cancer and viral infections, highlighting the need for new research tools.
• Uncoordinated 119 (UNC119) is a lipid-binding chaperone that regulates myristoylated protein transport.

Purpose of the Study:

• To develop novel photoactivatable probes for studying protein myristoylation.
• To investigate the interaction between these probes and the UNC119 protein.
• To explore the utility of myristate analogues in parasitic protozoa.

Main Methods:

• Synthesis of diazirine-substituted myristic acid analogues as photoactivatable probes.
• Irradiation of probes to induce covalent labeling of UNC119.
• Affinity enrichment techniques to demonstrate UNC119 interaction in cell lysate.
• Testing the incorporation of myristate analogues by N-myristoyl transferases in parasitic protozoa.

Main Results:

• The developed probes successfully bind to and covalently label UNC119 upon photoactivation.
• The binding mode of the probes mimics that of myristate, and key residues in UNC119's hydrophobic pocket were identified.
• UNC119 interaction was confirmed in cell lysates using affinity enrichment.
• Myristate analogues were shown to be incorporated by N-myristoyl transferases in Leishmania and Trypanosoma.

Conclusions:

• Photoactivatable myristate analogues are effective tools for studying protein myristoylation and UNC119 interactions.
• This research provides insights into the mechanism of UNC119 binding and identifies critical residues.
• The findings suggest potential applications of myristate analogues in understanding and targeting parasitic protozoa.