<> "The repository administrator has not yet configured an RDF license."^^ . <> . . "Structure of the microtubule nucleation sites"^^ . "Microtubules (MTs) are part of cytoskeleton responsible for cell cargo trafficking, cell shape and cell division. Nucleation of microtubules occurs at specific cellular organelle called microtubule organizing centrum (MTOCs). As the mayor microtubule nucleator is consider g tubulin complexes (gTuC). In lower eukaryotes it is created via tetrameric complex created by GCP2, GCP3 and two copies of g-tubulins, called g tubulin small complex (gTuSC). In higher eukaryotes the complex is more intricate, formed with additional GCPs (GCP4-6). I have precipitated in discovery of the structure of vertebrates gTuRC (g-tubulin ring complex). Surprisingly, vertebrates gTuRC is asymmetric to microtubule symmetry and deep inside of its structure is embedded actin molecule.\r\nMy PhD worked focused on understanding which conformational changes occurs in γTuRC upon microtubule nucleation and what is the fate of actin. Therefore, I established protocols for purification of gTuRC capped microtubule minus ends for purposes of the cryo EM analysis and the biochemical analysis.\r\nFrom structure of Xenopus leavis gTuRC capped microtubule minus ends induced via RanGTP chromosomal pathway, I could observe the misalignment of MT protofilaments from spokes of gTuRC and as well as partial closure of gTuRC. These features may be recognised by MTs minus end binding proteins (-TIPs). I could demonstrate it with CAMSAP2, MT -TIPs proteins. CAMSAP2 specifically recognise the native or recombinantly prepared gTuRC capped microtubule minus ends. As well as I could demonstrate the increased MT nucleation in Xenopus leavis egg’s extract with influence of CAMSAP2 and katanin p60.\r\nWith immunofluorescence analysis, I identified actin inside gTuRC. I could deny the possibility of actin filaments assembly from this position. I have purified the Drosophila melanogaster γTuRC, that resembled the conformation of vertebrates gTuRC and have densities corresponding to actin densities in vertebrates gTuRC. By omitting actin binding site, I could purify intact actin-deficient gTuRC from human cells and confirm that actin is not necessary for gTuRC assembly. By analysing the position of actin inside of gTuRC capped microtubule minus, I could observe the repositioning of actin densities, suggesting its involment into MT nucleation.\r\nMine work brought better insight into understanding of microtubule nucleation and its regulation."^^ . "2024" . . . . . . . "Anna"^^ . "Böhler"^^ . "Anna Böhler"^^ . . . . . . "Structure of the microtubule nucleation sites (PDF)"^^ . . . "DISSERTATION Anna Boehler .pdf"^^ . . . "Structure of the microtubule nucleation sites (Other)"^^ . . . . . . "indexcodes.txt"^^ . . . "Structure of the microtubule nucleation sites (Other)"^^ . . . . . . "lightbox.jpg"^^ . . . "Structure of the microtubule nucleation sites (Other)"^^ . . . . . . "preview.jpg"^^ . . . "Structure of the microtubule nucleation sites (Other)"^^ . . . . . . "medium.jpg"^^ . . . "Structure of the microtubule nucleation sites (Other)"^^ . . . . . . "small.jpg"^^ . . "HTML Summary of #35489 \n\nStructure of the microtubule nucleation sites\n\n" . "text/html" . .