Activity profiling of vacuolar processing enzymes reveals a role for VPE during oomycete infection. (28th December 2012)

• Record Type: Journal Article
• Authors: Misas‐Villamil, Johana C.; Toenges, Gerrit; Kolodziejek, Izabella; Sadaghiani, Amir M.; Kaschani, Farnusch; Colby, Thomas; Bogyo, Matthew; van der, Renier A.L.
• Is Part Of: Plant journal. Volume 73:Number 4(2013:Feb.)
• Page Start: 689
• Page End: 700
• Publication Date: 2012-12-28
• Subjects: Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.12062
• Languages: English
• ISSNs: 0960-7412

Abstract

<abstract abstract-type="main" id="tpj12062-abs-0001"> <title>Summary</title> <p>Vacuolar processing enzymes (VPEs) are important cysteine proteases that are implicated in the maturation of seed storage proteins, and programmed cell death during plant–microbe interactions and development. Here, we introduce a specific, cell‐permeable, activity‐based probe for VPEs. This probe is highly specific for all four Arabidopsis VPEs, and labeling is activity‐dependent, as illustrated by sensitivity for inhibitors, pH and reducing agents. We show that the probe can be used for <italic>in vivo</italic> imaging and displays multiple active isoforms of VPEs in various tissues and in both monocot and dicot plant species. Thus, VPE activity profiling is a robust, simple and powerful tool for plant research for a wide range of applications. Using VPE activity profiling, we discovered that VPE activity is increased during infection with the oomycete pathogen <italic>Hyaloperonospora arabidopsidis</italic> (<italic>Hpa</italic>). The enhanced VPE activity is host‐derived and <italic>EDS1</italic>‐independent. Sporulation of <italic>Hpa</italic> is reduced on <italic>vpe</italic> mutant plants, demonstrating a role for VPE during compatible interactions that is presumably independent of programmed cell death. Our data indicate that, as an obligate biotroph, <italic>Hpa</italic> takes advantage of increased VPE activity in the host, e.g. to mediate protein turnover and nutrient release.</p> </abstract>