Influence of YES1 Kinase and Tyrosine Phosphorylation on the Activity of OCT1

Area of Science:

• Biochemistry
• Pharmacology
• Molecular Biology

Background:

• Organic cation transporter 1 (OCT1) is crucial for hepatic uptake and elimination of cationic compounds.
• OCT1 plays a role in drug-drug interactions and pharmacokinetic variability.
• The molecular mechanisms regulating OCT1 activity are not fully understood.

Purpose of the Study:

• To investigate the post-translational regulation of OCT1.
• To identify molecular targets that modulate OCT1 activity.
• To assess the impact of kinase inhibitors on OCT1 function.

Main Methods:

• Unbiased phospho-proteomics screen to identify phosphorylated transporters.
• Functional validation using genetic and pharmacological approaches.
• In vivo studies in mice using targeted metabolomics to identify biomarkers.

Main Results:

• OCT1 was identified as a tyrosine-phosphorylated transporter.
• OCT1 activity is sensitive to small molecules targeting the protein kinase YES1, such as dasatinib.
• Dasatinib inhibited hepatic OCT1 function in mice, affecting isobutyryl L-carnitine levels.

Conclusions:

• OCT1 is regulated by tyrosine phosphorylation, modulated by the kinase YES1.
• Dasatinib, a YES1 inhibitor, can reduce hepatic OCT1 function.
• Caution is advised when combining OCT1 substrates with YES1-targeting kinase inhibitors due to potential drug interactions.