title: Arabidopsis type I metacaspases control cell death.
abstract: Metacaspases are distant relatives of animal caspases found in protozoa, fungi, and plants. Limited experimental data exist defining their function(s), despite their discovery by homology modeling a decade ago. We demonstrated that two type I metacaspases, AtMC1 and AtMC2, antagonistically control programmed cell death in Arabidopsis. AtMC1 is a positive regulator of cell death and requires conserved caspase-like putative catalytic residues for its function. AtMC2 negatively regulates cell death. This function is independent of the putative catalytic residues. Manipulation of the Arabidopsis type I metacaspase regulatory module can nearly eliminate the hypersensitive cell death response (HR) activated by plant intracellular immune receptors. This does not lead to enhanced pathogen proliferation, decoupling HR from restriction of pathogen growth.
authors.affiliation: Department of Biology, 108 Coker Hall, University of North Carolina (UNC), CB 3280, Chapel Hill, NC 27599-3280, USA.
authors.forename: Nuria S
authors.initials: NS
authors.lastname: Coll
authors.forename: Dominique
authors.initials: D
authors.lastname: Vercammen
authors.forename: Andrea
authors.initials: A
authors.lastname: Smidler
authors.forename: Charles
authors.initials: C
authors.lastname: Clover
authors.forename: Frank
authors.initials: F
authors.lastname: Van Breusegem
authors.forename: Jeffery L
authors.initials: JL
authors.lastname: Dangl
authors.forename: Petra
authors.initials: P
authors.lastname: Epple
mesh_terms: D017209:Apoptosis; D017360:Arabidopsis / Q000201:enzymology* / Q000276:immunology / Q000382:microbiology / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020169:Caspases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D009868:Oomycetes / Q000502:physiology; D010935:Plant Diseases / Q000276:immunology / Q000382:microbiology; D030821:Plants, Genetically Modified; D044224:Pseudomonas syringae / Q000502:physiology; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016335:Zinc Fingers
chemical_list: D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; C104920:LSD1 protein, Arabidopsis; C095014:RPM1 protein, Arabidopsis; C107295:RPP5 protein, Arabidopsis; D014157:Transcription Factors; D020169:Caspases; C554451:MC1 protein, Arabidopsis; C554452:MC2 protein, Arabidopsis