title: Identification of the ligand of Pru p 3, a peach LTP.
abstract: Pru p 3, a peach LTP, is located in pollinated flower styles and secreting downy hairs, transporting a derivative of camptothecin bound to phytosphingosine. Pru p 3 may inhibit a second pollination and may keep away herbivores until seed maturation. The allergen Pru p 3, a peach lipid transfer protein, has been well studied. However, its physiological function remains to be elucidated. Our results showed that Pru p 3 usually carries a lipid ligand that play an essential role in its function in plants. Using ESI-qToF, we observed that the ligand was a derivative of camptothecin binding to phytosphingosine, wich that is inserted into the hydrophobic tunnel of the protein. In addition, the described ligand displayed topoisomerase I activity inhibition and self-fluorescence, both recognized as camptothecin properties. During flower development, the highest expression of Pru p 3 was detected in the styles of pollinated flowers, in contrast to its non-expression in unpollinated pistils, where expression decreased after anthesis. During ripening, the expression of Pru p 3 were observed mainly in peel but not in pulp. In this sense, Pru p 3 protein was also localized in trichomes covering the fruit epidermis.
authors.affiliation: Centre for Plant Biotechnology and Genomics (UPM-INIA), Campus de Montegancedo, 28223, Pozuelo de Alarcón, Madrid, Spain.|Department of Biotechnology-Plant Biology, ETSIAAB, Technical University of Madrid, Madrid, Spain.
authors.forename: Nuria
authors.initials: N
authors.lastname: Cubells-Baeza
authors.affiliation: Department of Experimental Medical Sciences, Lund University, Lund, Sweden.
authors.forename: Cristina
authors.initials: C
authors.lastname: Gómez-Casado
authors.affiliation: Icahn School of Medicine at Mount Sinai, New York, USA.
authors.forename: Leticia
authors.initials: L
authors.lastname: Tordesillas
authors.affiliation: Centre for Plant Biotechnology and Genomics (UPM-INIA), Campus de Montegancedo, 28223, Pozuelo de Alarcón, Madrid, Spain.|Department of Biotechnology-Plant Biology, ETSIAAB, Technical University of Madrid, Madrid, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Ramírez-Castillejo
authors.affiliation: Centre for Plant Biotechnology and Genomics (UPM-INIA), Campus de Montegancedo, 28223, Pozuelo de Alarcón, Madrid, Spain.|Department of Biotechnology-Plant Biology, ETSIAAB, Technical University of Madrid, Madrid, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Garrido-Arandia
authors.affiliation: Centre for Plant Biotechnology and Genomics (UPM-INIA), Campus de Montegancedo, 28223, Pozuelo de Alarcón, Madrid, Spain.|Department of Biotechnology-Plant Biology, ETSIAAB, Technical University of Madrid, Madrid, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: González-Melendi
authors.affiliation: Estación Experimental de Aula Dei (CSIC), Zaragoza, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Herrero
authors.affiliation: Centre for Plant Biotechnology and Genomics (UPM-INIA), Campus de Montegancedo, 28223, Pozuelo de Alarcón, Madrid, Spain.|Department of Natural Systems and Resources, ETSI Montes, Technical University of Madrid, Madrid, Spain.
authors.forename: Luis F
authors.initials: LF
authors.lastname: Pacios
authors.affiliation: Centre for Plant Biotechnology and Genomics (UPM-INIA), Campus de Montegancedo, 28223, Pozuelo de Alarcón, Madrid, Spain. araceli.diaz@upm.es.|Department of Biotechnology-Plant Biology, ETSIAAB, Technical University of Madrid, Madrid, Spain. araceli.diaz@upm.es.
authors.forename: Araceli
authors.initials: A
authors.lastname: Díaz-Perales
mesh_terms: D002166:Camptothecin / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism*; D035264:Flowers / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000502:physiology*; D008958:Models, Molecular; D010940:Plant Proteins / Q000378:metabolism*; D011058:Pollen / Q000502:physiology; D011487:Protein Conformation; D000068239:Prunus persica / Q000378:metabolism*; D013110:Sphingosine / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D010940:Plant Proteins; C572509:Pru p 4 allergen, Prunus persica; C012491:phytosphingosine; D013110:Sphingosine; D002166:Camptothecin
keywords: Camptothecin; Flower development; Fruit development; Lipid transfer protein; Pollination; Pru p 3; Secondary metabolites