Capturing Differences in the Regulation of LRRK2 Dynamics and Conformational States by Small Molecule Kinase...

Area of Science:

• Biochemistry
• Structural Biology
• Neuroscience

Background:

• Mutations in leucine-rich repeat kinase-2 (LRRK2) are associated with Parkinson's disease risk.
• Aberrant LRRK2 kinase activity is linked to its pathological functions.
• Previous research has focused on developing selective LRRK2 kinase inhibitors.

Purpose of the Study:

• To investigate the dynamic changes and allosteric communication within LRRK2 C-terminal domains induced by kinase inhibitors.
• To characterize the distinct effects of type I and type II kinase inhibitors on LRRK2 conformation.
• To identify key interdomain interactions regulating communication between LRRK2's kinase and GTPase domains.

Main Methods:

• Enhanced sampling simulations were employed to model LRRK2 dynamics.
• Hydrogen-deuterium exchange mass spectrometry (HDX-MS) was used to probe structural changes.
• The study focused on the LRRK2 C-terminal domains (LRRK2^RCKW).

Main Results:

• The type I inhibitor MLi-2 stabilized a compact, closed kinase conformation of LRRK2^RCKW.
• The type II inhibitor Rebastinib stabilized an extended, open kinase conformation of LRRK2^RCKW.
• Distinct inhibitor-induced conformational changes revealed interdomain interactions governing kinase-GTPase communication.

Conclusions:

• Understanding inhibitor-specific effects on LRRK2 dynamics is crucial for Parkinson's disease research.
• The identified intermediate states can guide in silico design of allosteric modulators.
• Targeting LRRK2 conformations may offer novel therapeutic strategies for Parkinson's disease.