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Delivery of Proteins, Peptides or Cell-impermeable Small Molecules into Live Cells by Incubation with the Endosomolytic Reagent dfTAT
Published on: September 2, 2015
A novel function for the cathepsin D inhibitor in tomato
Purificación Lisón1, Ismael Rodrigo, Vicente Conejero
1Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, 46022 Valencia, Spain.
Plant Physiology
|October 3, 2006
Summary
This study identifies a tomato protein, jasmonic-induced protein 21 (JIP21), initially thought to inhibit aspartic proteinases. Biochemical analysis reveals it strongly inhibits chymotrypsin, acting as a serine proteinase inhibitor and impacting insect pests.
Area of Science:
- Plant biochemistry
- Molecular biology
- Insect toxicology
Background:
- Proteinaceous aspartic proteinase inhibitors (CDIs) are rare, with known isoforms in potato.
- Tomato jasmonic-induced protein 21 (JIP21) was predicted to function as a CDI based on sequence analysis.
Purpose of the Study:
- To characterize the function of tomato JIP21.
- To investigate the role of JIP21 in plant defense against insect herbivores.
Main Methods:
- Sequence analysis of JIP21 cDNA and genomic DNA.
- Biochemical characterization of purified JIP21 protein.
- Analysis of insect mortality and growth on transgenic tomato plants overexpressing JIP21.
Main Results:
- JIP21 is a wound-inducible, glycosylated protein with an intronless gene containing regulatory elements.
- Biochemical assays revealed JIP21 is a potent chymotrypsin inhibitor, not an aspartic proteinase inhibitor.
- Overexpression of JIP21 in tomato plants increased mortality and delayed growth in Egyptian cotton worm larvae.
Conclusions:
- Tomato JIP21 functions as a serine proteinase inhibitor, specifically targeting chymotrypsin.
- JIP21 plays a role in plant defense against Lepidoptera pests.
- The protein is renamed tomato chymotrypsin inhibitor 21 (TCI21).
