Molecular structure and functions of vacuolar processing enzymes in plants

Vacuolar processing enzymes (VPEs) are plant proteases belonging to the C13 protease family. The specific activity of VPEs was characterized by comparing them to animal caspases. VPEs perform many important functions at various stages of plant ontogenesis, playing a role not only in the proper development of the plant organism but also in plant reactions to biotic and abiotic stress factors. A particularly important role of VPEs is noted in the processing of vacuolar proteins, enabling the production of their mature and active forms. VPEs are involved in programmed cell death, but despite residual evidence, we also suggest that VPEs are involved in autophagy. Based on literature data on autophagy in yeast, we formulate a hypothesis that VPEs during autophagy in plant cells are involved in the degradation of autophagic bodies - one of the final stages of autophagy.