STED nanoscopy of the centrosome linker reveals a CEP68-organized, periodic rootletin network anchored to a C-Nap1 ring at centrioles

  • The centrosome linker proteins C-Nap1, rootletin, and CEP68 connect the two centrosomes of a cell during interphase into one microtubule-organizing center. This coupling is important for cell migration, cilia formation, and timing of mitotic spindle formation. Very little is known about the structure of the centrosome linker. Here, we used stimulated emission depletion (STED) microscopy to show that each C-Nap1 ring at the proximal end of the two centrioles organizes a rootletin ring and, in addition, multiple rootletin/CEP68 fibers. Rootletin/CEP68 fibers originating from the two centrosomes form a web-like, interdigitating network, explaining the flexible nature of the centrosome linker. The rootletin/CEP68 filaments are repetitive and highly ordered. Staggered rootletin molecules (N-to-N and C-to-C) within the filaments are 75 nm apart. Rootletin binds CEP68 via its C-terminal spectrin repeat-containing region in 75-nm intervals. The N-to-C distance of two rootletin molecules is ∼35 to 40 nm, leading to an estimated minimal rootletin length of ∼110 nm. CEP68 is important in forming rootletin filaments that branch off centrioles and to modulate the thickness of rootletin fibers. Thus, the centrosome linker consists of a vast network of repeating rootletin units with C-Nap1 as ring organizer and CEP68 as filament modulator.
Author:Rifka Vlijm, Xue Li, Marko Panic, Diana Rüthnick, Shoji Hata, Frank Herrmannsdörfer, Thomas Kuner, Mike HeilemannORCiDGND, Johann Engelhardt, Stefan Hell, Elmar Schiebel
Pubmed Id:
Parent Title (English):Proceedings of the National Academy of Sciences of the United States of America
Publisher:National Acad. of Sciences
Place of publication:Washington, DC
Contributor(s):Laurence Pelletier, Jordan Raff
Document Type:Article
Year of Completion:2018
Date of first Publication:2018/02/20
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2018/11/13
Tag:CEP68; STED superresolution; centrosome; centrosome linker; rootletin
Page Number:8
First Page:E2246
Last Page:E2253
This open access article is distributed under Creative Commons Attribution-NonCommercialNoDerivatives License 4.0 (CC BY-NC-ND).
Institutes:Biochemie, Chemie und Pharmazie / Biochemie und Chemie
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 54 Chemie / 540 Chemie und zugeordnete Wissenschaften
Licence (German):License LogoCreative Commons - Namensnennung-Nicht kommerziell - Keine Bearbeitung 4.0