PLD2-PI(4,5)P2 interactions in fluid phase membranes: Structural modeling and molecular dynamics simulations

Area of Science:

• Biochemistry
• Molecular Biology
• Structural Biology

Background:

• Phospholipase D2 (PLD2) plays a vital role in numerous physiological processes.
• The interaction between PLD2 and phosphatidylinositol (4,5)-bisphosphate (PIP2) is a critical regulatory step.

Purpose of the Study:

• To elucidate the molecular mechanisms of human PLD2 (hPLD2)-PIP2 interactions.
• To model the full-length hPLD2 protein and simulate its behavior at a complex membrane interface.

Main Methods:

• Utilized a combination of template-based and ab initio modeling to construct a full-length hPLD2 model.
• Performed microsecond all-atom molecular dynamics (MD) simulations of hPLD2 in proximity to a complex membrane.

Main Results:

• Identified specific PIP2 phosphate groups and hPLD2 residues, notably arginine in the PX and PH domains, as key interaction sites.
• Observed the formation of interaction clusters at the protein-membrane interface, involving amino acids, PIP2, and POPA.
• The largest and most significant cluster was localized within the PH domain of hPLD2.

Conclusions:

• The study provides atomic-level insights into the critical hPLD2-PIP2 interaction dynamics.
• These findings highlight the importance of specific residues and domain interactions in regulating PLD2 function.
• The identified interaction networks offer a structural basis for understanding PLD2-mediated signaling pathways.