Decoding Allosteric Control in Hypoxia-Inducible Factors

Area of Science:

• Molecular biology
• Structural biology
• Biochemistry

Background:

• Mammalian bHLH-PAS transcription factors sense environmental and physiological signals.
• These proteins form dimers via bHLH domains for DNA binding.
• The bHLH-PAS family is implicated in major human diseases, presenting therapeutic targets.

Purpose of the Study:

• To review the structural and allosteric mechanisms of the HIF subfamily of bHLH-PAS proteins.
• To highlight the potential for targeted small molecule drug development.

Main Methods:

• Analysis of crystal structures of HIF-α proteins and their interaction with ARNT.
• Review of recent findings on allosteric modulation by small molecules.

Main Results:

• The crystal structures of HIF-α proteins reveal their interaction with ARNT.
• Small molecules binding to PAS-B domains allosterically modulate HIF-α transcriptional activity.
• Approved drugs like Belzutifan and Tapinarof target bHLH-PAS proteins.

Conclusions:

• Understanding bHLH-PAS protein architecture and allostery is key to drug discovery.
• Targeting ligand-binding cavities in PAS domains enables the development of novel therapeutics.
• Advances in this field offer promising avenues for treating diseases linked to bHLH-PAS dysfunction.