ABSTRACT
Structure and properties of the recently discovered aspartate-specific cell death-related plant proteases named phytaspases are reviewed and compared to those of animal apoptotic proteases, caspases. Caspases (cysteine-dependent proteases) and phytaspases (serine-dependent proteases) are structurally very different, yet they share cleavage specificity and a role in programmed cell death. We demonstrate here that the distinctions in structural organization of animal and plant death proteases define differences in the strategies to regulate functioning of these proteolytic enzymes in the two kingdoms.
Subject(s)
Caspases/metabolism , Peptide Hydrolases/chemistry , Plant Cells/enzymology , Plant Proteins/chemistry , Animals , Apoptosis/genetics , Aspartic Acid/chemistry , Aspartic Acid/metabolism , Caspases/chemistry , Peptide Hydrolases/metabolism , Plant Proteins/metabolism , Serine Endopeptidases/chemistry , Serine Endopeptidases/metabolism , Substrate SpecificityABSTRACT
The modern concepts of programmed cell death (PCD) in plants are reviewed as compared to PCD (apoptosis) in animals. Special attention is focused on considering the potential mechanisms of implementation of this fundamental biological process and its participants. In particular, the proteolytic enzymes involved in PCD in animals (caspases) and plants (phytaspases) are compared. Emphasis is put on elucidation of both common features and substantial differences of PCD implementation in plants and animals.
