The characterization of plasma membrane-bound tubulin of cauliflower using Triton X-114 fractionation
Author
Summary, in English
The cortical microtubules determine how cellulose microfibrils are deposited in the plant cell wall and are thus important for the control of cell expansion. To understand how microtubules can control microfibril deposition, the components that link the microtubules to the plasma membrane (PM) of plant cells must be isolated. To obtain information on the properties of the tubulin-membrane associations, cauliflower (Brassica oleracea) PM was subjected to Triton X-114 fractionation, and the distribution of α- and β-tubulin was analyzed using immunoblotting. Approximately one-half of the PM-associated tubulin was solubilized by Triton X-114 and 10 to 15 % of both α- and β-tubulin was recovered in the detergent phase (indicative of hydrophobic properties) and 30 to 40% was recovered in the aqueous phase. The hydrophobic tubulin could be released from the membrane by high pH extraction with preserved hydrophobicity. A large part of the PM-associated tubulin was found in the Triton-insoluble fraction. When this insoluble material was extracted a second time, a substantial amount of hydrophobic tubulin was released if the salt concentration was increased, suggesting that the hydrophobic tubulin was linked to a high-salt-sensitive protein aggregate that probably includes other components of the cytoskeleton. The hydrophobicity of a fraction of PM-associated tubulin could reflect a direct or indirect interaction of this tubulin with the lipid bilayer or with an integral membrane protein and may represent the anchoring of the cortical microtubules to the PM, a key element in the regulation of cell expansion.
Department/s
Publishing year
1997
Language
English
Pages
1001-1007
Publication/Series
Plant Physiology
Volume
115
Issue
3
Links
Document type
Journal article
Publisher
American Society of Plant Biologists
Topic
- Biological Sciences
Keywords
- Brassica
- Cell Membrane
- Detergents
- Hydrogen-Ion Concentration
- Membrane Proteins
- Polyethylene Glycols
- Tubulin
Status
Published
ISBN/ISSN/Other
- ISSN: 1532-2548