Sla2 is a core interaction hub for clathrin light chain and the Pan1/End3/Sla1 complex

Area of Science:

• Cell Biology
• Molecular Biology
• Biophysics

Background:

• Sla2 is a key endocytic adaptor protein linking the cell membrane to the actin cytoskeleton.
• Clathrin light chain (CLC) regulates Sla2 function, inhibiting it under specific conditions.
• Understanding Sla2 interactions is vital for mapping endocytic checkpoints.

Purpose of the Study:

• To investigate the interaction network of Sla2, focusing on its binding sites for CLC.
• To elucidate the structural basis of Sla2 regulation by CLC.
• To map the interactions of Sla2 with regulatory proteins Sla1 and Pan1.

Main Methods:

• Cryoelectron microscopy for structural modeling of Sla2 domains.
• AI modeling for predicting protein interactions.
• Molecular biophysics techniques for experimental validation.

Main Results:

• Sla2 possesses two independent CLC binding sites: one conserved and one fungal-specific.
• A structural model of Sla2 actin-binding domains was determined.
• An interaction map of Sla2, Sla1, and Pan1 was generated, suggesting Pan1 competes with CLC for a binding site.

Conclusions:

• The findings reveal distinct fungal mechanisms in Sla2 regulation compared to metazoans.
• This work enhances the understanding of endocytic checkpoint regulation.
• The study highlights evolutionary divergence in the Sla2 interaction network between Fungi and Metazoa.