Molecular Cloning and Characterization of a Vacuolar Class III Peroxidase Involved in the Metabolism of Anticancer Alkaloids in Catharanthus roseus

Avaliação de mutagenicidade e antimutagenicidade de diferentes frações de Pterogyne nitens (Leguminosae), utilizando ensaio de micronúcleo em Tradescantia pallida

“…Diversos estudos vêm sendo conduzidos para a utilização de drogas que tenham como mecanismo de ação a ligação ao DNA (aductos) ou que se intercalem seletivamente neste, induzindo sinais intracelulares que levem as células tumorais a apoptose (Havelka et al, 2007;Wheate et al, 2007). A vincristina, e a camptotecina são alcalóides naturais, que vêm sendo utilizados na oncologia por interferir na organização de microtúbulos e inibir a topoisomerase I respectivamente (Costa et al, 2008, Sirikantaramas et al, 2007.…”

Cloning and Characterization of a Candidate Gene from the Medicinal Plant Catharanthus roseus Through Transient Expression in Mesophyll Protoplasts

“…When compared to any characterized mature plant Prx, all vacuolar Prxs show the presence of a C-terminal extension (CTE) in their deduced amino-acid sequence (Welinder et al, 2002). Previous results obtained in our laboratory revealed that the CTE of CroPrx1 is both necessary and sufficient to target the sGFP reporter to the central vacuole, both in C. roseus bombarded cells and in Arabidopsis protoplasts, and must therefore constitute the Prx vacuolar sorting signal (Costa et al, 2008;Duarte et al, 2010). In contrast with the high number of studies on cell wall Prxs, much less is known about their vacuolar counterparts (Costa et al, 2008;Welinder et al, 2002).…”

“…We identified a leaf class III peroxidase (Prx) with AVLB synthase activity and we purified and characterized this enzyme, which was named Catharanthus roseus peroxidase 1, CroPrx1 (Bakalovic et al, 2006; Peroxibase, http://peroxibase.toulouse.inra.fr index.php). We have further shown the localization of CroPrx1 in the same subcellular compartment where alkaloids accumulate, the vacuole, through biochemical and molecular methodologies, and we performed the cloning and molecular characterization of CroPrx1 (Costa et al, 2008;Duarte et al, 2010;Sottomayor et al, 1996;Sottomayor et al, 1998). In the course of this work, we have discovered, cloned and characterized another Prx gene from C. roseus, CroPrx3, which will be addressed in this chapter.…”

“…Regarding subcellular localization, Prxs are either vacuolar or extracellular. They are targeted to the secretory pathway by an Nterminal signal peptide (SP) that directs the protein to the endoplasmic reticulum (ER), from where they follow the default pathway to the cell wall, or they are sorted to the vacuole if an additional sorting signal exists (Costa et al, 2008). When compared to any characterized mature plant Prx, all vacuolar Prxs show the presence of a C-terminal extension (CTE) in their deduced amino-acid sequence (Welinder et al, 2002).…”

Predicting the functionally distinct residues in the heme, cation, and substrate-binding sites of peroxidase from stress-tolerant mangrove specie, Avicennia marina

“…Binding of such ligands is mutually exclusive and fully competitive toward peroxide binding (Carlsson et al 2005). Class III peroxidases recognize a number of vacuolar metabolites, such as phenols, flavonoids, and alkaloids as substrates, and assume specific functions in the metabolism of these compounds in vivo (Costa et al 2008;Passardi et al 2004;Welinder et al 2002).…”