Fig. 5: POC5-Augmin-NEDD1 interactions tether γ-TuRCs to the inner centriolar wall.

a Structure of the Augmin complex with subunits colored as indicated (PDB: 7SQK). b AlphaFold2 prediction of the interaction between POC5 and the Augmin TII N-clamp. c Representative immunoprecipitation results using HEK293 cell lysate with overexpressed POC5-HA or POC5^mut-HA. EGFP pull down of HAUS7-EGFP-8His (TII) and HAUS1-EGFP-8His (TIII) proteins was performed to enrich Augmin subcomplexes. The 8His tag was used for the detection of HAUS proteins. Buffer only and Augmin TIII was used as the negative controls. HA detection was used to compare the bound POC5^WT and POC5^mut. d Quantification (mean ± SD) of band intensities from the immunoprecipitation experiment in (c) normalized to POC5^WT, based on N = 3 independent experiments. Statistical analysis was performed using an unpaired two-tailed t test. e AlphaFold2 prediction of the interaction between the NEDD1 grapnel and Augmin TIII, Coloring as indicated. The location of the C-terminal SNAP-S tag on HAUS1 is indicated by a red arrow. The C-terminus of NEDD1 is indicated by the letter c. f Representative confocal (upper left) and MINFLUX images (upper right) after endogenous tagging of HAUS1 with a C-terminal SNAP-S tag labeled via BG-AF647 (see red arrow in (e) and Supplementary Fig. 20). Scale bars: 5 µm. The lower image panels show zoomed 3D renderings of the HAUS1-SNAP-S BGAF647 organization highlighted by the dashed white square. The structure is rotated in each image around 90° to show side and top views. All scale bars: 50 nm. N = 3 biologically independent experiments. g Centriole radial distribution of HAUS1-SNAP-S signal from MINFLUX (n = 17 centrosomes) (gray) relative to centriole-lumenal γ-TuRC coordinates from cellular cryo-ET (red) (n = 5 centrioles). h Integrated structural model (predicted) for γ-TuRC recruitment to the centriole lumen by POC5 and Augmin. Coloring as indicated. Source data are provided as a Source Data file.