title: The Grapevine VvPMEI1 Gene Encodes a Novel Functional Pectin Methylesterase Inhibitor Associated to Grape Berry Development.
abstract: Pectin is secreted in a highly methylesterified form and partially de-methylesterified in the cell wall by pectin methylesterases (PMEs). PME activity is expressed during plant growth, development and stress responses. PME activity is controlled at the post-transcriptional level by proteins named PME inhibitors (PMEIs). We have identified, expressed and characterized VvPMEI1, a functional PME inhibitor of Vitis vinifera. VvPMEI1 typically affects the activity of plant PMEs and is inactive against microbial PMEs. The kinetics of PMEI-PME interaction, studied by surface plasmon resonance, indicates that the inhibitor strongly interacts with PME at apoplastic pH while the stability of the complex is reduced by increasing the pH. The analysis of VvPMEI1 expression in different grapevine tissues and during grape fruit development suggests that this inhibitor controls PME activity mainly during the earlier phase of berry development. A proteomic analysis performed at this stage indicates a PME isoform as possible target of VvPMEI1.
authors.affiliation: Dipartimento di Biologia e Biotecnologie "C. Darwin", Sapienza Università di Roma, Rome, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Lionetti
authors.affiliation: Dipartimento Territorio e Sistemi Agroforestali, Università di Padova, Legnaro (PD), Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Raiola
authors.affiliation: Dipartimento di Biologia e Biotecnologie "C. Darwin", Sapienza Università di Roma, Rome, Italy.
authors.forename: Benedetta
authors.initials: B
authors.lastname: Mattei
authors.affiliation: Dipartimento di Biologia e Biotecnologie "C. Darwin", Sapienza Università di Roma, Rome, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Bellincampi
mesh_terms: D002265:Carboxylic Ester Hydrolases / Q000378:metabolism*; D002473:Cell Wall / Q000235:genetics / Q000378:metabolism; D005638:Fruit / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D040901:Proteomics; D027843:Vitis / Q000235:genetics* / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D002265:Carboxylic Ester Hydrolases; C022323:pectinesterase