Garagounis, Constantine and Kostaki, Kalliopi-Ioanna and Hawkins, Tim J. and Cummins, Ian and Fricker, Mark D. and Hussey, Patrick J. and Hetherington, Alistair M. and Sweetlove, Lee J. (2017) 'Microcompartmentation of cytosolic aldolase by interaction with the actin cytoskeleton in Arabidopsis.', Journal of experimental botany., 68 (5). pp. 885-898.
Evidence is accumulating for molecular microcompartments formed when proteins interact in localized domains with the cytoskeleton, organelle surfaces, and intracellular membranes. To understand the potential functional significance of protein microcompartmentation in plants, we studied the interaction of the glycolytic enzyme fructose bisphosphate aldolase with actin in Arabidopsis thaliana. Homology modelling of a major cytosolic isozyme of aldolase, FBA8, suggested that the tetrameric holoenzyme has two actin binding sites and could therefore act as an actin-bundling protein, as was reported for animal aldolases. This was confirmed by in vitro measurements of an increase in viscosity of F-actin polymerized in the presence of recombinant FBA8. Simultaneously, interaction with F-actin caused non-competitive inhibition of aldolase activity. We did not detect co-localization of an FBA8–RFP fusion protein, expressed in an fba8-knockout background, with the actin cytoskeleton using confocal laser-scanning microscopy. However, we did find evidence for a low level of interaction using FRET-FLIM analysis of FBA8–RFP co-expressed with the actin-binding protein GFP–Lifeact. Furthermore, knockout of FBA8 caused minor alterations of guard cell actin cytoskeleton morphology and resulted in a reduced rate of stomatal closure in response to decreased humidity. We conclude that cytosolic aldolase can be microcompartmented in vivo by interaction with the actin cytoskeleton and may subtly modulate guard cell behaviour as a result.
|Full text:||(AM) Accepted Manuscript|
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|Publisher Web site:||https://doi.org/10.1093/jxb/erx015|
|Publisher statement:||This is a pre-copyedited, author-produced PDF of an article accepted for publication in Journal of Experimental Botany following peer review. The version of record Garagounis, Constantine, Kostaki, Kalliopi-Ioanna, Hawkins, Tim J., Cummins, Ian, Fricker, Mark D., Hussey, Patrick J., Hetherington, Alistair M. & Sweetlove, Lee J. (2017). Microcompartmentation of cytosolic aldolase by interaction with the actin cytoskeleton in Arabidopsis. Journal Of Experimental Botany 68(5): 885-898 is available online at: https://doi.org/10.1093/jxb/erx015.|
|Date accepted:||07 January 2017|
|Date deposited:||17 February 2017|
|Date of first online publication:||17 February 2017|
|Date first made open access:||17 February 2018|
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