Disease relevance of ATPPC3

• Here, we describe a gene from Arabidopsis, stated as Atppc4, encoding a PEPC, which shows more similarity to Escherichia coli than to plant PEPCs [1].
• The phylogenetic analysis suggests that both plant-type and bacterial-type PEPCs diverged early during the evolution of plants from a common ancestor, probably the PEPC from gamma-proteobacteria [1].
• Among them, the calcium-dependent protein kinase and phosphoenolpyruvate carboxylase kinase families are specific for plants, whereas the Ca(2+)/calmodulin-dependent protein kinase and provirus insertion in mouse-like kinase families were found only in yeast and animals [2].

High impact information on ATPPC3

• Coenzyme A biosynthesis in plants is not fully understood, and to date only the AtHAL3a (AtCoaC) gene of Arabidopsis thaliana has been cloned and identified as 4'-phosphopantothenoylcysteine (PPC) decarboxylase (Kupke, T., Hernández-Acosta, P., Steinbacher, S., and Culiáñez-Macià, F. A. (2001) J. Biol. Chem. 276, 19190-19196) [3].
• We report the expression patterns of five PEPC genes, including one encoding a bacterial-type PEPc lacking the phosphorylation site of the plant-type PEPcs [4].
• We have analyzed the expression of both PPCK genes and the PEPC genes that encode PEPc in soybean (Glycine max) [4].
• Hypo-osmotic treatment of the cells increased the amount of PEPC that bound the PA beads without increasing the absolute amount of PEPC [5].
• As most plant PEPC genes, Atppc1, Atppc2, and Atppc3 are formed by 10 exons interrupted by nine introns [1].

Biological context of ATPPC3

• Interestingly, this enzyme lacks the phosphorylation domain, hence indicating that it is a bacterial-type PEPC [1].
• Salt and drought exerted a differential induction of PEPC gene expression in roots, Atppc4 showing the highest induction in response to both stresses [6].
• AHL1 contains an AT-hook motif and unknown conserved PPC (plants and prokaryotes conserved) domain that includes a hydrophobic region [7].
• The AT-hook motif was essential for matrix attachment region (MAR) binding, and the hydrophobic region of the PPC was indispensable for nuclear localization [7].
• Our results suggest that AHL1 is a novel plant MAR binding protein, which is related to the positioning of chromatin fibers in the nucleus by the presence of an AT-hook motif and PPC domain [7].

Analytical, diagnostic and therapeutic context of ATPPC3

• Based on sequence analysis it was deduced that Atppc1, Atppc2 and Atppc3 genes encode plant-type PEPCs, whereas Atppc4 encodes a PEPC without phosphorylation motif, but no data at the protein level have been reported [6].
• Western-blot analysis of different Arabidopsis organs probed with anti plant-type PEPC antibodies detected a double band, the one with low molecular weight corresponding to the three plant-type PEPCs [6].

References