Structure of the human multidrug transporter ABCG2

Area of Science:

• Structural Biology
• Molecular Biology
• Biochemistry

Background:

• ABCG2 (ATP-binding cassette transporter G2) is a key transporter protecting tissues from xenobiotics.
• Its function impacts drug pharmacokinetics and contributes to multidrug resistance in tumors.
• Understanding ABCG2 structure is crucial for developing targeted therapies.

Purpose of the Study:

• To determine the high-resolution structure of human ABCG2.
• To elucidate the molecular mechanisms of drug recognition and transport.
• To provide structural basis for antibody inhibition and cholesterol binding.

Main Methods:

• Cryo-electron microscopy (cryo-EM) for high-resolution structure determination.
• Complex formation with inhibitory antibody 5D3 antigen-binding fragments.
• In vitro functional analyses.

Main Results:

• First high-resolution structure of human ABCG2 determined.
• Identified cholesterol molecules bound within the central multidrug-binding pocket.
• Visualized ABCG2 in complex with inhibitory antibody 5D3, revealing allosteric inhibition mechanism.
• Provided structural insights into drug recognition, transport, and disease-associated SNPs.

Conclusions:

• The study provides unprecedented structural insight into human ABCG2 function.
• The findings elucidate the mechanisms of multidrug recognition, transport, and antibody-mediated inhibition.
• This structural information is vital for understanding ABCG2-related drug resistance and developing novel therapeutics.
• The structure reveals cholesterol binding, offering insights into G-subfamily ABC transporter mechanisms.