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.
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.
Delmas
Frédéric
F
Unité Mixte de Recherche 619 de Physiologie et Biotechnologie Végétales, Institut de Biologie Végétale Moléculaire, Centre de Recherche Institut National de la Recherche Agronomique-Bordeaux, boite postale 81, 33883 Villenave d'Ornon cedex, France.
Petit
Johann
J
Joubès
Jérôme
J
Séveno
Martial
M
Paccalet
Thomas
T
Hernould
Michel
M
Lerouge
Patrice
P
Mouras
Armand
A
Chevalier
Christian
C
D000446:Aldehyde-Lyases / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D002453:Cell Cycle / Q000235:genetics / Q000502:physiology*; D002455:Cell Division / Q000235:genetics / Q000502:physiology; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D005638:Fruit / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D018546:Hypocotyl / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D018551:Solanum lycopersicum / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014026:Nicotiana / Q000201:enzymology / Q000235:genetics
D018076:DNA, Complementary; D010940:Plant Proteins; D012333:RNA, Messenger; C020011:2-dehydro-3-deoxyphosphooctonate aldolase; D000446:Aldehyde-Lyases