File talk:Centrosome cartoon.jpg

3D-structured illumination microscopy provides novel insight into architecture of human centrosomes

Biol Open. 2012 Oct 15;1(10):965-76. doi: 10.1242/bio.20122337. Epub 2012 Aug 8.

Sonnen KF, Schermelleh L, Leonhardt H, Nigg EA. Source Biozentrum, University of Basel , Klingelbergstrasse 50/70, CH-4056 Basel , Switzerland.

Abstract

Centrioles are essential for the formation of cilia and flagella. They also form the core of the centrosome, which organizes microtubule arrays important for cell shape, polarity, motility and division. Here, we have used super-resolution 3D-structured illumination microscopy to analyse the spatial relationship of 18 centriole and pericentriolar matrix (PCM) components of human centrosomes at different cell cycle stages. During mitosis, PCM proteins formed extended networks with interspersed γ-Tubulin. During interphase, most proteins were arranged at specific distances from the walls of centrioles, resulting in ring staining, often with discernible density masses. Through use of site-specific antibodies, we found the C-terminus of Cep152 to be closer to centrioles than the N-terminus, illustrating the power of 3D-SIM to study protein disposition. Appendage proteins showed rings with multiple density masses, and the number of these masses was strongly reduced during mitosis. At the proximal end of centrioles, Sas-6 formed a dot at the site of daughter centriole assembly, consistent with its role in cartwheel formation. Plk4 and STIL co-localized with Sas-6, but Cep135 was associated mostly with mother centrioles. Remarkably, Plk4 formed a dot on the surface of the mother centriole before Sas-6 staining became detectable, indicating that Plk4 constitutes an early marker for the site of nascent centriole formation. Our study provides novel insights into the architecture of human centrosomes and illustrates the power of super-resolution microscopy in revealing the relative localization of centriole and PCM proteins in unprecedented detail.

PMID 23213374

http://bio.biologists.org/content/1/10/965.full

Human centriole cylinder

built of nine triplet microtubules (MTs)
approximate diameters of 150–200 nm
approximate lengths of 400–450 nm

Centrosome

comprises two centrioles surrounded by an amorphous protein cloud (100 different proteins)
older centriole (mother)
- carries distinctive distal and subdistal appendages.

Basal bodies

form either de novo or from the oldest
platforms for the formation of motile and immotile cilia
primary cilia are generated in the G1/G0 phase by diverting the centriole to the basal body.
9+2 multiciliogenesis involves neogenesis of basal bodies around the deuterosome deep inside the cytosol.
9+0 cilia in choroid plexus epithelial cells (CPECs) http://bio.biologists.org/content/1/8/815.full

(Beisson and Wright, 2003; Dawe et al., 2007; Guirao et al., 2010; Vladar and Stearns, 2007).