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The RUB/Nedd8 conjugation pathway is required for early development in Arabidopsis
Author(s) -
Dharmasiri Sunethra,
Dharmasiri Nihal,
Hellmann Hanjo,
Estelle Mark
Publication year - 2003
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/cdg190
Subject(s) - cullin , nedd8 , arabidopsis , microbiology and biotechnology , skp1 , biology , auxin , ubiquitin , mutant , arabidopsis thaliana , biochemistry , ubiquitin ligase , chemistry , gene
The r elated‐to‐ ub iquitin (RUB) protein is post‐translationally conjugated to the cullin subunit of the SCF (SKP1, Cullin, F‐box) class of ubiquitin protein ligases. Although the precise biochemical function of RUB modification is unclear, studies indicate that the modification is important for SCF function. In Arabidopsis , RUB modification of CUL1 is required for normal function of SCF TIR1 , an E3 required for response to the plant hormone auxin. In this report we show that an Arabidopsis protein called RCE1 functions as a RUB‐conjugating enzyme in vivo . A mutation in the RCE1 gene results in a phenotype like that of the axr1 mutant. Most strikingly, plants deficient in both RCE1 and AXR1 have an embryonic phenotype similar to mp and bdl mutants, previously shown to be deficient in auxin signaling. Based on these results, we suggest that the RUB‐conjugation pathway is required for auxin‐dependent pattern formation in the developing embryo. In addition, we show that RCE1 interacts directly with the RING protein RBX1 and is present in a stable complex with SCF. We propose that RBX1 functions as an E3 for RUB modification of CUL1.