The Plant Plasma Memrbane H+-ATPase: regulation by phosphorylation and 14-3-3 proteins
(2000)- Abstract
- The plant plasma membrane H<sup>+</sup>-ATPase is a predominant membrane enzyme that provides the energy for secondary active transport across the plasma membrane. Consequently, the H<sup>+</sup>-ATPase is thought to play a major role in many cell processes, and it is implicated to be regulated by a number of factors, including hormones, blue light, and fungal toxins
The plant plasma membrane H<sup>+</sup>-ATPase is regulated via an autoinhibitory domain located within the C-terminal region of the enzyme. Removal or displacement of this regulatory domain results in an activated enzyme with a lower K<sub>m</sub>, a higher V<sub>max</sub>, a more alkaline pH... (More) - The plant plasma membrane H<sup>+</sup>-ATPase is a predominant membrane enzyme that provides the energy for secondary active transport across the plasma membrane. Consequently, the H<sup>+</sup>-ATPase is thought to play a major role in many cell processes, and it is implicated to be regulated by a number of factors, including hormones, blue light, and fungal toxins
The plant plasma membrane H<sup>+</sup>-ATPase is regulated via an autoinhibitory domain located within the C-terminal region of the enzyme. Removal or displacement of this regulatory domain results in an activated enzyme with a lower K<sub>m</sub>, a higher V<sub>max</sub>, a more alkaline pH optimum, and an improved coupling between ATP hydrolysis and proton pumping.
Characterization of the H<sup>+</sup>-ATPase activities of leaf and root plasma membranes from tobacco (<i>Nicotiana tabacum</i>) revealed a difference in the activation state of the enzymes in the two organs. This discovery led to the suggestion that there are at least two regulatory sites within the C-terminal autoinhibitory domain, one regulating V<sub>max</sub>, and another regulating K<sub>m</sub> and pH optimum.
The fungal toxin fusicoccin activates the H<sup>+</sup>-ATPase by a mechanism involving a displacement of the C-terminal autoinhibitory domain. We have shown that the fusicoccin ¨receptor¨, a 14-3-3 protein, binds directly to the C-terminal region of the H<sup>+</sup>-ATPase and that fusicoccin stabilizes a 14-3-3/H<sup>+</sup>-ATPase complex, which represents the activated state of the enzyme.
14-3-3 proteins bind to phosphorylated motifs in their target proteins. <i>In vivo</i> phosphorylation of the plasma membrane H<sup>+</sup>-ATPase from spinach leaves in the presence of fusicoccin made it possible to identify a phosphorylated amino acid in the C terminus. The phosphorylation of this amino acid residue, Thr-948, the penultimate amino acid in the C terminus, was protected by the fusicoccin-dependent binding of 14-3-3 to the C terminus. Characterization of this novel 14-3-3 binding motif, QQXYpT<sub>948</sub>V, revealed that phosphorylation of Thr-948 is a prerequisite for binding of 14-3-3. Moreover, we could show that the fusicoccin-dependent 14-3-3 binding occurs independently of phosphorylation but still involves the three ultimate amino acids, YT<sub>948</sub>V. Finally, we demonstrate that the phosphothreonine motif is important for the binding of 14-3-3, and hence in the activation the H<sup>+</sup>-ATPase, also <i>in vivo</i>.
Taken together our data show that 14-3-3 is a natural ligand of the H<sup>+</sup>-ATPase regulating H<sup>+</sup>-pumping, that phosphorylation of Thr-948 is a prerequisite for 14-3-3 binding, and that fusicoccin replaces the need for phosphorylation of Thr-948. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/40606
- author
- Olsson, Anne LU
- supervisor
- opponent
-
- Prof Aducci, Patrizia, Dept. of Biology, Università di Roma Tor Vergata, Via della Ricerca Scientifica, 00133 Roma, Italien
- organization
- publishing date
- 2000
- type
- Thesis
- publication status
- published
- subject
- keywords
- phosphorylation, fusicoccin, 14-3-3, C-terminus, autoinhibitory domain, plasma membrane, plant, H+-ATPase, Plant biochemistry, Växtbiokemi
- pages
- 106 pages
- publisher
- Maivi Åkesson, växtbiokemi, Lunds Universitet
- defense location
- Sölvegatan 35, Lund
- defense date
- 2000-06-09 10:15:00
- external identifiers
-
- other:ISRN: LUNKDL/NK VK-00/1016
- ISBN
- 91-973252-5-2
- language
- English
- LU publication?
- yes
- additional info
- Article: Olsson, A., Johansson, F., Sommarin, M., and Larsson, C. (1995)Multiple regulatory sites in the C-terminal autoinhibitory domain of the plasma membrane H+-ATPase. Plant J. 8, 959-962 Article: Jahn, T., Fuglsang, T.A., Olsson, A., Brüntrup, I.M., Collinge, D.B., Volkmann, D., Sommarin, M., Palmgren, M.G., and Larsson, C. (1997)The 14-3-3 protein interacts directly with the C-terminal region of the plant plasma membrane H+-ATPase. Plant Cell 9, 1805-1814 Article: Olsson, A., Svennelid, F., Ek, B., Sommarin, M., and Larsson, C. (1998)A phosphothreonine residue at the C-terminal end of the plasma membrane H+-ATPase is protected by fusicoccin-induced 14-3-3 binding. Plant Physiol. 118, 551-555 Article: Svennelid, F., Olsson, A., Piotrowski, M., Rosenquist, M., Ottman, C., Larsson, C., Oecking, C., and Sommarin, M. (1999)Phosphorylation of Thr-948 in the C terminus of the plasma membrane H+-ATPase creates a binding site for the regulatory 14-3-3 protein. Plant Cell 11, 2379-2392
- id
- 5a669bb1-7afb-4d43-97d8-fe6f88395e0e (old id 40606)
- date added to LUP
- 2016-04-04 12:18:39
- date last changed
- 2018-11-21 21:10:12
@phdthesis{5a669bb1-7afb-4d43-97d8-fe6f88395e0e,
abstract = {{The plant plasma membrane H<sup>+</sup>-ATPase is a predominant membrane enzyme that provides the energy for secondary active transport across the plasma membrane. Consequently, the H<sup>+</sup>-ATPase is thought to play a major role in many cell processes, and it is implicated to be regulated by a number of factors, including hormones, blue light, and fungal toxins<br/><br>
<br/><br>
The plant plasma membrane H<sup>+</sup>-ATPase is regulated via an autoinhibitory domain located within the C-terminal region of the enzyme. Removal or displacement of this regulatory domain results in an activated enzyme with a lower K<sub>m</sub>, a higher V<sub>max</sub>, a more alkaline pH optimum, and an improved coupling between ATP hydrolysis and proton pumping.<br/><br>
<br/><br>
Characterization of the H<sup>+</sup>-ATPase activities of leaf and root plasma membranes from tobacco (<i>Nicotiana tabacum</i>) revealed a difference in the activation state of the enzymes in the two organs. This discovery led to the suggestion that there are at least two regulatory sites within the C-terminal autoinhibitory domain, one regulating V<sub>max</sub>, and another regulating K<sub>m</sub> and pH optimum.<br/><br>
<br/><br>
The fungal toxin fusicoccin activates the H<sup>+</sup>-ATPase by a mechanism involving a displacement of the C-terminal autoinhibitory domain. We have shown that the fusicoccin ¨receptor¨, a 14-3-3 protein, binds directly to the C-terminal region of the H<sup>+</sup>-ATPase and that fusicoccin stabilizes a 14-3-3/H<sup>+</sup>-ATPase complex, which represents the activated state of the enzyme.<br/><br>
<br/><br>
14-3-3 proteins bind to phosphorylated motifs in their target proteins. <i>In vivo</i> phosphorylation of the plasma membrane H<sup>+</sup>-ATPase from spinach leaves in the presence of fusicoccin made it possible to identify a phosphorylated amino acid in the C terminus. The phosphorylation of this amino acid residue, Thr-948, the penultimate amino acid in the C terminus, was protected by the fusicoccin-dependent binding of 14-3-3 to the C terminus. Characterization of this novel 14-3-3 binding motif, QQXYpT<sub>948</sub>V, revealed that phosphorylation of Thr-948 is a prerequisite for binding of 14-3-3. Moreover, we could show that the fusicoccin-dependent 14-3-3 binding occurs independently of phosphorylation but still involves the three ultimate amino acids, YT<sub>948</sub>V. Finally, we demonstrate that the phosphothreonine motif is important for the binding of 14-3-3, and hence in the activation the H<sup>+</sup>-ATPase, also <i>in vivo</i>.<br/><br>
<br/><br>
Taken together our data show that 14-3-3 is a natural ligand of the H<sup>+</sup>-ATPase regulating H<sup>+</sup>-pumping, that phosphorylation of Thr-948 is a prerequisite for 14-3-3 binding, and that fusicoccin replaces the need for phosphorylation of Thr-948.}},
author = {{Olsson, Anne}},
isbn = {{91-973252-5-2}},
keywords = {{phosphorylation; fusicoccin; 14-3-3; C-terminus; autoinhibitory domain; plasma membrane; plant; H+-ATPase; Plant biochemistry; Växtbiokemi}},
language = {{eng}},
publisher = {{Maivi Åkesson, växtbiokemi, Lunds Universitet}},
school = {{Lund University}},
title = {{The Plant Plasma Memrbane H<sup>+</sup>-ATPase: regulation by phosphorylation and 14-3-3 proteins}},
year = {{2000}},
}