The ubiquitin-specific protease UBP14 is essential for early embryo development in Arabidopsis thaliana

Citation
Jh. Doelling et al., The ubiquitin-specific protease UBP14 is essential for early embryo development in Arabidopsis thaliana, PLANT J, 27(5), 2001, pp. 393-405
Citations number
45
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Plant Sciences","Animal & Plant Sciences
Journal title
PLANT JOURNAL
ISSN journal
0960-7412 → ACNP
Volume
27
Issue
5
Year of publication
2001
Pages
393 - 405
Database
ISI
SICI code
0960-7412(200109)27:5<393:TUPUIE>2.0.ZU;2-W
Abstract
The ubiquitin/26S proteasome pathway is a major route for selectively degra ding cytoplasmic and nuclear proteins in eukaryotes. In this pathway, chain s of ubiquitins become attached to short-lived proteins, signalling recogni tion and breakdown of the modified protein by the 26S proteasome. During or following target degradation, the attached multi-ubiquitin chains are rele ased and subsequently disassembled by ubiquitin-specific proteases (UBPs) t o regenerate free ubiquitin monomers for re-use. Here, we describe Arabidop sis thaliana UBP14 that may participate in this recycling process. Its amin o acid sequence is most similar to yeast UBP14 and its orthologues, human I soT1-3 and Dictyostelium UbpA, and it can functionally replace yeast UBP14 in a ubp14 Delta mutant. Like its orthologues, AtUBP14 can disassemble mult i-ubiquitin chains linked internally via epsilon -amino isopeptide bonds us ing Lys48 and can process some, but not all, translational fusions of ubiqu itin linked via alpha -amino peptide bonds. However, unlike its yeast and D ictyostelium orthologues, AtUBP14 is essential in Arabidopsis. T-DNA insert ion mutations in the single gene that encodes AtUBP14 cause an embryonic le thal phenotype, with the homozygous embryos arresting at the globular stage . The arrested seeds have substantially increased levels of multi-ubiquitin chains, indicative of a defect in ubiquitin recycling. Taken together, the data demonstrate an essential role for the ubiquitin/26S proteasome pathwa y in general and for AtUBP14 in particular during early plant development.