KDEL-tailed cysteine endopeptidases involved in programmed cell death, intercalation of new cells, and dismantling of extensin scaffolds
KDEL-tailed cysteine endopeptidases are a group of papain-type peptidases found in senescing tissue undergoing programmed cell death (PCD). Their genes have so far been cloned and analyzed in 12 angiosperms. They are synthesized as proenzymes with a C-terminal KDEL endoplasmatic reticulum retention...
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Published in | American journal of botany Vol. 95; no. 9; pp. 1049 - 1062 |
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Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
Botanical Society of America
01.09.2008
Botanical Soc America Botanical Society of America, Inc |
Subjects | |
Online Access | Get full text |
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Summary: | KDEL-tailed cysteine endopeptidases are a group of papain-type peptidases found in senescing tissue undergoing programmed cell death (PCD). Their genes have so far been cloned and analyzed in 12 angiosperms. They are synthesized as proenzymes with a C-terminal KDEL endoplasmatic reticulum retention signal, which is removed with the prosequence to activate enzyme activity. We previously identified three genes for KDEL-tailed cysteine endopeptidases (AtCEP1, AtCEP2, AtCEP3) in Arabidopsis thaliana. Transgenic plants of A. thaliana expressing β-glucuronidase (GUS) under the control of the promoters for the three genes were produced and analyzed histochemically. GUS activity was promoter- and tissue-specific GUS activity during seedling, flower, and root development, especially in tissues that collapse during final stages of PCD, and in the course of lateral root formation. KDEL-tailed cysteine endopeptidases are unique in being able to digest the extensins that form the basic scaffold for cell wall formation. The broad substrate specificity is due to the structure of the active site cleft of the KDEL-tailed cysteine endopeptidase that accepts a wide variety of amino acids, including proline and glycosylated hydroxyproline of the hydroxyproline rich glycoproteins of the cell wall. |
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Bibliography: | Present address: Max‐Plank‐Institut für Entwicklungsbiologie, Spemannstr. 37‐39, D‐72076 Tübingen, Germany The authors thank H. Cochran (Washington State University, USA) for artwork, J. S. Greenwood (University of Guelph, Canada) for valuable discussions, and D. Simpson (Denmark) for critically reading the manuscript. This work was supported by the Deutsche Forschungsgemeinschaft (Gi154/11‐5). ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0002-9122 1537-2197 1537-2197 |
DOI: | 10.3732/ajb.2007404 |