title: Juggling jobs: roles and mechanisms of multifunctional protease inhibitors in plants.
abstract: Multifunctional protease inhibitors juggle jobs by targeting different enzymes and thereby often controlling more than one biological process. Here, we discuss the biological functions, mechanisms and evolution of three types of multifunctional protease inhibitors in plants. The first type is double-headed inhibitors, which feature two inhibitory sites targeting proteases with different specificities (e.g. Bowman-Birk inhibitors) or even different hydrolases (e.g. α-amylase/protease inhibitors preventing both early germination and seed predation). The second type consists of multidomain inhibitors which evolved by intragenic duplication and are released by processing (e.g. multicystatins and potato inhibitor II, implicated in tuber dormancy and defence, respectively). The third type consists of promiscuous inhibitory folds which resemble mouse traps that can inhibit different proteases cleaving the bait they offer (e.g. serpins, regulating cell death, and α-macroglobulins). Understanding how multifunctional inhibitors juggle biological jobs increases our knowledge of the connections between the networks they regulate. These examples show that multifunctionality evolved independently from a remarkable diversity of molecular mechanisms that can be exploited for crop improvement and provide concepts for protein design.
authors.affiliation: Plant Chemetics Laboratory, Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK.
authors.forename: Friederike M
authors.initials: FM
authors.lastname: Grosse-Holz
authors.affiliation: Plant Chemetics Laboratory, Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK.
authors.forename: Renier A L
authors.initials: RA
authors.lastname: van der Hoorn
mesh_terms: D008958:Models, Molecular; D010944:Plants / Q000378:metabolism*; D011480:Protease Inhibitors / Q000737:chemistry / Q000378:metabolism*; D012106:Research
chemical_list: D011480:Protease Inhibitors
keywords: plant defence; protease inhibitors; protein structure; regulatory networks; resistance breeding; storage protein protection