γ-Tubulin Complexes and Fibrillar Arrays: Two Conserved High Molecular Forms with Many Cellular Functions

Abstract

Higher plants represent a large group of eukaryotes where centrosomes are absent. The functions of γ-tubulin small complexes (γ-TuSCs) and γ-tubulin ring complexes (γ-TuRCs) in metazoans and fungi in microtubule nucleation are well established and the majority of components found in the complexes are present in plants. However, plant microtubules are also nucleated in a γ-tubulin-dependent but γ-TuRC-independent manner. There is growing evidence that γ-tubulin is a microtubule nucleator without being complexed in γ-TuRC. Fibrillar arrays of γ-tubulin were demonstrated in plant and animal cells and the ability of γ-tubulin to assemble into linear oligomers/polymers was confirmed in vitro for both native and recombinant γ-tubulin. The functions of γ-tubulin as a template for microtubule nucleation or in promoting spontaneous nucleation is outlined. Higher plants represent an excellent model for studies on the role of γ-tubulin in nucleation due to their acentrosomal nature and high abundancy and conservation of γ-tubulin including its intrinsic ability to assemble filaments. The defining scaffolding or sequestration functions of plant γ-tubulin in microtubule organization or in nuclear processes will help our understanding of its cellular roles in eukaryotes.

Keywords

microtubules; plants; gamma-tubulin; gamma-tubulin complexes; fibrillar arrays; nucleation; signaling; sequestration

Published in

Cells
2021, volume: 10, number: 4, article number: 776

SLU Authors

• Daniel, Geoffrey

  • Department of Forest Biomaterials and Technology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Biochemistry and Molecular Biology

Publication identifier

• DOI: https://doi.org/10.3390/cells10040776

Permanent link to this page (URI)

https://res.slu.se/id/publ/111316