Fig. 5.

LRRK2 has membrane-curvature-sensing and generating properties. (A) and (B) Narrow lipid tubules were pulled from GUVs composed of an acid phospholipid mixture and exposed to a low concentration (20 nM) of GFP-LRRK2 in the presence or absence of the indicated nucleotides (5 mM). (A) Representative fluorescence images demonstrating that GFP-LRRK2 is preferentially recruited to the tubules revealing that it has curvature-sensing properties. (B) Plot showing the sorting ratio of GFP-LRRK2 on individual tubules. Ratios were defined as the ratios between the protein density (GFP-LRRK2 fluorescence relative to the fluorescence of Atto 647N DOPE) on the tubules and the protein density on the surface of the GUV. A calibration curve allowed to derive the tubule diameter from the lipid fluorescence. Each data point corresponds to a different membrane tubule. (C–E) When used at high concentration (500 nm), GFP-LRRK2 assembles into high-density scaffolds on the surface of the tubules, leading to membrane constriction. (C) Representative example of a GFP-LRRK2 scaffold formed on a lipid tubule pulled from a GUV, in the presence of GTP (5 mM). (D) Examples of GFP-LRRK2 scaffolds on lipid tubules generated by the lipid covered silica bead system, in the presence or absence of the indicated nucleotides (5 mM). (E) Quantification of tubule diameter in segments covered or noncovered by the GFP-LRRK2 scaffolds, in the presence of GTP (5 mM).