PEST sequences from a cactus dehydrin regulate its proteolytic degradation

"Dehydrins (DHNs) are intrinsically disordered proteins expressed under cellular dehydration-related stresses. In this study, we identified potential proteolytic PEST sequences located at the central and C-terminal regions from the Opuntia streptacantha OpsDHN1 protein. In order to evaluate the...

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Bibliographic Details
Authors: ADRIANA LETICIA SALAZAR RETANA, Israel Maruri López, Itzell Eurídice Hernández Sánchez, ALICIA BECERRA FLORA, María de la Luz Guerrero González, JUAN FRANCISCO JIMENEZ BREMONT
Format: article
Status:Published version
Publication Date:2019
Country:México
Institution:Instituto Potosino de Investigación Científica y Tecnológica
Repository:Repositorio Institucional del IPICYT
OAI Identifier:oai:ipicyt.repositorioinstitucional.mx:1010/2140
Online Access:http://ipicyt.repositorioinstitucional.mx/jspui/handle/1010/2140
Access Level:Open access
Keyword:info:eu-repo/classification/Autor/Dehydrin
info:eu-repo/classification/Autor/Intrinsically disordered proteins
info:eu-repo/classification/Autor/Pest sequences
info:eu-repo/classification/Autor/Protein degradation
info:eu-repo/classification/cti/2
info:eu-repo/classification/cti/24
info:eu-repo/classification/cti/2415
Description
Summary:"Dehydrins (DHNs) are intrinsically disordered proteins expressed under cellular dehydration-related stresses. In this study, we identified potential proteolytic PEST sequences located at the central and C-terminal regions from the Opuntia streptacantha OpsDHN1 protein. In order to evaluate these PEST sequences as proteolytic tags, we generated a translational fusion with the GUS reporter protein and OpsDHN1 coding sequence. We found a GUS degradation effect in tobacco agro-infiltrated leaves and Arabidopsis transgenic lines that expressed the fusion GUS::OpsDHN1 full-length. Also, two additional translational fusions between OpsDHN1 protein fragments that include the central (GUS::PEST-1) or the C-terminal (GUS::PEST-2) PEST sequences were able to decrease the GUS activity, with PEST-2 showing the greatest reduction in GUS activity. GUS signal was abated when the OpsDHN1 fragment that includes both PEST sequences (GUS::PEST-1-2) were fused to GUS. Treatment with the MG132 proteasome inhibitor attenuated the PEST-mediated GUS degradation. Point mutations of phosphorylatable residues in PEST sequences reestablished GUS signal, hence these sequences are important during protein degradation. Finally, in silico analysis identified potential PEST sequences in other plant DHNs. This is the first study reporting presence of PEST motifs in dehydrins."