title: Isolation and characterization of a Solanum tuberosum subtilisin-like protein with caspase-3 activity (StSBTc-3).
abstract: Plant proteases with caspase-like enzymatic activity have been widely studied during the last decade. Previously, we have reported the presence and induction of caspase-3 like activity in the apoplast of potato leaves during Solanum tuberosum- Phytophthora infestans interaction. In this work we have purified and identified a potato extracellular protease with caspase-3 like enzymatic activity from potato leaves infected with P. infestans. Results obtained from the size exclusion chromatography show that the isolated protease is a monomeric enzyme with an estimated molecular weight of 70 kDa approximately. Purified protease was analyzed by MALDI-TOF MS, showing a 100% of sequence identity with the deduced amino acid sequence of a putative subtilisin-like protease from S. tuberosum (Solgenomics protein ID: PGSC0003DMP400018521). For this reason the isolated protease was named as StSBTc-3. This report constitutes the first evidence of isolation and identification of a plant subtilisin-like protease with caspase-3 like enzymatic activity. In order to elucidate the possible function of StSBTc-3 during plant pathogen interaction, we demonstrate that like animal caspase-3, StSBTc-3 is able to produce in vitro cytoplasm shrinkage in plant cells and to induce plant cell death. This result suggest that, StSBTc-3 could exert a caspase executer function during potato- P. infestans interaction, resulting in the restriction of the pathogen spread during plant-pathogen interaction.
authors.affiliation: Instituto de Investigaciones Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata-CONICET, CC 1245, 7600 Mar del Plata, Argentina. Electronic address: mbfernan@mdp.edu.ar.
authors.forename: María Belén
authors.initials: MB
authors.lastname: Fernández
authors.affiliation: Instituto de Investigaciones Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata-CONICET, CC 1245, 7600 Mar del Plata, Argentina. Electronic address: grdaleo@mdp.edu.ar.
authors.forename: Gustavo Raúl
authors.initials: GR
authors.lastname: Daleo
authors.affiliation: Instituto de Investigaciones Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata-CONICET, CC 1245, 7600 Mar del Plata, Argentina. Electronic address: gguevara@mdp.edu.ar.
authors.forename: María Gabriela
authors.initials: MG
authors.lastname: Guevara
mesh_terms: D000595:Amino Acid Sequence; D017209:Apoptosis / Q000235:genetics; D001483:Base Sequence; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D004591:Electrophoresis, Polyacrylamide Gel; D054884:Host-Pathogen Interactions; D018551:Solanum lycopersicum / Q000166:cytology; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010802:Phylogeny; D055750:Phytophthora infestans / Q000502:physiology; D059828:Plant Cells / Q000378:metabolism; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D011198:Solanum tuberosum / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D020860:Subtilisin / Q000145:classification / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D020860:Subtilisin; D053148:Caspase 3
keywords: Apoplast; DEVDase; Plant–pathogen interaction; Solanum tuberosum; Subtilisin like protein