Subcellular localization of Arabidopsis arogenate dehydratases suggests novel and non-enzymatic roles.

Autor:	Bross CD; Department of Biology, Western University, 1151 Richmond Street North, London Ontario, N6A 5B7, Canada., Howes TR; Department of Biology, Western University, 1151 Richmond Street North, London Ontario, N6A 5B7, Canada., Abolhassani Rad S; Department of Biology, Western University, 1151 Richmond Street North, London Ontario, N6A 5B7, Canada., Kljakic O; Department of Biology, Western University, 1151 Richmond Street North, London Ontario, N6A 5B7, Canada., Kohalmi SE; Department of Biology, Western University, 1151 Richmond Street North, London Ontario, N6A 5B7, Canada.
Jazyk:	angličtina
Zdroj:	Journal of experimental botany [J Exp Bot] 2017 Mar 01; Vol. 68 (7), pp. 1425-1440.
DOI:	10.1093/jxb/erx024
Abstrakt:	Arogenate dehydratases (ADTs) catalyze the final step in phenylalanine biosynthesis in plants. The Arabidopsis thaliana genome encodes a family of six ADTs capable of decarboxylating/dehydrating arogenate into phenylalanine. Using cyan fluorescent protein (CFP)-tagged proteins, the subcellular localization patterns of all six A. thaliana ADTs were investigated in intact Nicotiana benthamiana and A. thaliana leaf cells. We show that A. thaliana ADTs localize to stroma and stromules (stroma-filled tubules) of chloroplasts. This localization pattern is consistent with the enzymatic function of ADTs as many enzymes required for amino acid biosynthesis are primarily localized to chloroplasts, and stromules are thought to increase metabolite transport from chloroplasts to other cellular compartments. Furthermore, we provide evidence that ADTs have additional, non-enzymatic roles. ADT2 localizes in a ring around the equatorial plane of chloroplasts or to a chloroplast pole, which suggests that ADT2 is a component of the chloroplast division machinery. In addition to chloroplasts, ADT5 was also found in nuclei, again suggesting a non-enzymatic role for ADT5. We also show evidence that ADT5 is transported to the nucleus via stromules. We propose that ADT2 and ADT5 are moonlighting proteins that play an enzymatic role in phenylalanine biosynthesis and a second role in chloroplast division or transcriptional regulation, respectively. (© The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.)
Databáze:	MEDLINE
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