Intrinsically disordered regions in autophagy proteins

Area of Science:

• Cellular Biology
• Biochemistry
• Bioinformatics

Background:

• Autophagy is a vital cellular process for maintaining homeostasis.
• Key regulators and effectors of autophagy are known, but their mechanisms remain unclear.
• The role of intrinsically disordered regions (IDRs) in autophagy is largely uninvestigated.

Purpose of the Study:

• To investigate the role of intrinsically disordered regions (IDRs) in human autophagy proteins.
• To analyze the structural and functional characteristics of IDRs in autophagy.
• To explore the involvement of IDRs in protein-protein interactions within the autophagy pathway.

Main Methods:

• Bioinformatic analysis of human autophagy proteins to identify IDRs.
• Examination of available crystal structures for predicted IDRs.
• Analysis of ortholog conservation for IDR regions.
• Prediction and network analysis of protein-protein interactions involving IDRs.
• Experimental validation of IDRs in BECN1, including conformational changes.

Main Results:

• The majority of key human autophagy proteins contain IDRs.
• Predicted IDRs are poorly conserved in orthologs, suggesting diverse functions.
• IDRs are predicted to mediate protein-protein interactions, forming an interaction network.
• The BECN1 BCL2 homology 3 domain (BH3D) is an IDR that undergoes a coil-to-helix transition upon BCL2 binding.

Conclusions:

• IDRs play a significant, previously unappreciated role in autophagy.
• IDRs are involved in mediating protein-protein interactions critical for autophagy.
• The conformational flexibility of IDRs, exemplified by BECN1's BH3D, is key to their function in autophagy regulation.