An extended γ-tubulin ring functions as a stable platform in microtubule nucleation
Microtubule nucleation sites in yeast consist of a ring of γ-tubulin small complexes and a slight excess of uncomplexed γ-tubulin., γ-Tubulin complexes are essential for microtubule (MT) nucleation. The γ-tubulin small complex (γ-TuSC) consists of two molecules of γ-tubulin and one molecule each of...
Saved in:
| Main Authors: | , , , |
|---|---|
| Format: | Article (Journal) |
| Language: | English |
| Published: |
2 April, 2012
|
| In: |
The journal of cell biology
Year: 2012, Volume: 197, Issue: 1, Pages: 59-74 |
| ISSN: | 1540-8140 |
| DOI: | 10.1083/jcb.201111123 |
| Online Access: | Verlag, kostenfrei, Volltext: http://dx.doi.org/10.1083/jcb.201111123 Verlag, kostenfrei, Volltext: https://rupress.org/jcb/article/197/1/59/36846/An-extended-tubulin-ring-functions-as-a-stable 
|
| Author Notes: | Sarah Erlemann, Annett Neuner, Linda Gombos, Romain Gibeaux, Claude Antony, and Elmar Schiebel |
| Summary: | Microtubule nucleation sites in yeast consist of a ring of γ-tubulin small complexes and a slight excess of uncomplexed γ-tubulin., γ-Tubulin complexes are essential for microtubule (MT) nucleation. The γ-tubulin small complex (γ-TuSC) consists of two molecules of γ-tubulin and one molecule each of Spc97 and Spc98. In vitro, γ-TuSCs oligomerize into spirals of 13 γ-tubulin molecules per turn. However, the properties and numbers of γ-TuSCs at MT nucleation sites in vivo are unclear. In this paper, we show by fluorescence recovery after photobleaching analysis that γ-tubulin was stably integrated into MT nucleation sites and was further stabilized by tubulin binding. Importantly, tubulin showed a stronger interaction with the nucleation site than with the MT plus end, which probably provides the basis for MT nucleation. Quantitative analysis of γ-TuSCs on single MT minus ends argued for nucleation sites consisting of approximately seven γ-TuSCs with approximately three additional γ-tubulin molecules. Nucleation and anchoring of MTs required the same number of γ-tubulin molecules. We suggest that a spiral of seven γ-TuSCs with a slight surplus of γ-tubulin nucleates MTs in vivo. |
|---|---|
| Item Description: | Gesehen am 22.11.2018 |
| Physical Description: | Online Resource |
| ISSN: | 1540-8140 |
| DOI: | 10.1083/jcb.201111123 |