RRC ID 4027
Author Johnson KL, Faulkner C, Jeffree CE, Ingram GC.
Title The phytocalpain defective kernel 1 is a novel Arabidopsis growth regulator whose activity is regulated by proteolytic processing.
Journal Plant Cell
Abstract The role of the unique plant calpain Defective Kernel 1 (DEK1) in development has remained unclear due to the severity of mutant phenotypes. Here, we used complementation studies of the embryo-lethal mutant to dissect DEK1 protein behavior and to show that DEK1 plays a key role in growth regulation in Arabidopsis thaliana. We show that although full-length DEK1 protein localizes to membranes, it undergoes intramolecular autolytic cleavage events that release the calpain domain into the cytoplasm. The active calpain domain alone is not only necessary for DEK1 function but is sufficient for full complementation of dek1 mutants. A novel set of phenotypes, including leaf ruffling, increased leaf thickness, and abnormalities of epidermal cell interdigitation, was caused by expression of the constitutively active calpain domain. This analysis of the novel phenotypes produced by DEK1 under- and overexpression, as well as DEK1 subcellular localization and protein processing, has revealed a fundamental role for DEK1-mediated signaling in growth regulation.
Volume 20(10)
Pages 2619-30
Published 2008-10
DOI 10.1105/tpc.108.059964
PII tpc.108.059964
PMID 18952779
PMC PMC2590720
MeSH Arabidopsis / enzymology* Arabidopsis / genetics Arabidopsis / growth & development Arabidopsis Proteins / analysis Arabidopsis Proteins / chemistry Arabidopsis Proteins / genetics Arabidopsis Proteins / physiology* Calpain / analysis Calpain / chemistry Calpain / genetics Calpain / physiology* Cell Membrane / enzymology Cell Proliferation Cytoplasm / enzymology Endoplasmic Reticulum / enzymology Enzyme Activation / physiology Genetic Complementation Test Green Fluorescent Proteins / analysis Meristem / enzymology Meristem / growth & development Mutation Phenotype Plant Leaves / genetics Plant Leaves / growth & development Plant Leaves / metabolism Protein Structure, Tertiary Recombinant Fusion Proteins / analysis
IF 8.631
Times Cited 25
Arabidopsis / Cultured plant cells, genes pda04880