The Gene Expression and Enzyme Activity of Plant 3-Deoxy-D-Manno-2-Octulosonic Acid-8-Phosphate Synthase Are Preferentially Associated with Cell Division in a Cell Cycle-Dependent Manner

Abstract

3-Deoxy-d-manno-2-octulosonic acid-8-phosphate (Kdo-8-P) synthase catalyzes the condensation of phosphoenolpyruvate with d-arabinose-5-phosphate to yield Kdo-8-P. Kdo-8-P is the phosphorylated precursor of Kdo, a rare sugar only found in the rhamnogalacturonan II pectic fraction of the primary cell walls of higher plants and of cell wall polysaccharides of some green algae. A cDNA named LekdsA (accession no. AJ294902) encoding tomato (Lycopersicon esculentum) Kdo-8-P synthase has been isolated. The recombinant protein rescued a kdsA thermosensitive mutant of Salmonella typhimurium impaired in the synthesis of a functional Kdo-8-P synthase. Using site-directed mutagenesis of LekdsA cDNA, the tomato Kdo-8-P synthase was shown to possess the same essential amino acids that form the active sites in the bacterial enzymes. The tomato kdsA gene expression and the relevant Kdo-8-P synthase activity were preferentially associated to dividing cells, in the course of the early development of tomato fruit and in meristematic tissues. Furthermore, the transcription of the kdsA gene was found to oscillate during the cell cycle in tobacco (Nicotiana tabacum) Bright-Yellow 2 synchronized cells with a maximum during mitosis.

Expression of the 2-dehydro-3-deoxyphosphooc­tonate aldolase (KdsA) gene in mulberry leaves (Morus alba L.) is down-regulated under high salt and drought stress

“…This effect was confirmed in this study by our finding that KdsA expression was higher in the 2nd leaves than in the 8th leaves. Similar results have been reported elsewhere showing the preferential expression of the LeKdsA gene in dividing tissues and organs in the tomato (Delmas et al, 2003). Furthermore, AtKdsA2 is also expressed in reproductive tissues (Iwai et al, 2006).…”

“…KDO8Ps is widely expressed in higher plants (Brabetz et al, 2000;Delmas et al, 2003); however, biochemical and structural investigations of the enzyme have largely been limited to bacteria (Woisetschlager and Hogenauer, 1987;Brabetz and Brade, 1997;Sarkar et al, 2012). The first evidence of a plant KDO8Ps was provided by the detection of Kdo-8-P synthase-like activities in eight different plant species, and from the partial purification of KdsA and its characterization in spinach (Doong et al, 1991).…”

“…The first evidence of a plant KDO8Ps was provided by the detection of Kdo-8-P synthase-like activities in eight different plant species, and from the partial purification of KdsA and its characterization in spinach (Doong et al, 1991). Subsequently, Kdo-8-P synthase cDNA has been isolated from Pisum sativum (Brabetz et al, 2000), Solanum lycopersicum (Delmas et al, 2003), and Arabidopsis thaliana (Matsuura et al, 2003). Kdo-8-P synthase is encoded by a single-copy KdsA gene in tomato, but by two genes in Arabidopsis.…”

Structural characterisation of the pectic polysaccharide rhamnogalacturonan II using an acidic fingerprinting methodology

“…1). Such functional groups can be selectively coupled to 1,2-diamino-4,5-methylene dioxybenzene (DMB) forming Xuorescent derivatives (Delmas et al 2003). In order to selectively detect Kdo-and Dha-containing side-chains, citrus pectin RG-II was hydrolysed with 0.1 M TFA at 40°C for 16 h and the resulting mixture coupled to DMB before analysis by reverse-phase HPLC coupled to a Xuorescent detector.…”

Cell Wall Polysaccharide Synthesis

“…Functional genes encoding KDO-8-P synthase activity were isolated from various plant species (498)(499)(500) and the encoded proteins share ∼50% amino acid sequence identity with the bacterial proteins. In Arabidopsis, two gene isoforms (AtkdsA1, At1g79500; and AtkdsA2, At5g09730) were identified.…”