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FBXO 21 mediates the ubiquitylation and proteasomal degradation of EID 1
Author(s) -
Watanabe Koki,
Yumimoto Kanae,
Nakayama Keiichi I.
Publication year - 2015
Publication title -
genes to cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.912
H-Index - 115
eISSN - 1365-2443
pISSN - 1356-9597
DOI - 10.1111/gtc.12260
Subject(s) - biology , ubiquitin , degradation (telecommunications) , microbiology and biotechnology , proteasome , computational biology , biochemistry , engineering , gene , electrical engineering
Although identification of substrates for ubiquitin ligase (E3) is important for understanding its biological functions, detection of the interaction between an E3 and its substrates has remained challenging. We recently developed a new approach, termed di fferential p roteomics‐based i dentification of u biquitylation s ubstrates (Di PIUS ), for the discovery of substrates of a given E3 ligase. We have now applied this approach to an uncharacterized human F‐box protein, FBXO 21, which serves as the substrate‐recognition subunit of a SKP 1‐ CUL 1‐F‐box protein ( SCF )‐type E3, thereby identifying EID 1 ( EP 300‐interacting inhibitor of differentiation 1) as a candidate substrate. The central and COOH ‐terminal portion of FBXO 21 was found to interact with the COOH ‐terminal region of EID 1 in transfected cells. Over‐expression of FBXO 21 resulted in the down‐regulation of EID 1, whereas disruption of the FBXO 21 gene with the CRISPR /Cas9 system stabilized EID 1 and led to its accumulation in both the cytoplasm and nucleus. An in vitro ubiquitylation assay showed that EID 1 is a direct substrate of SCF FBXO 21 . Collectively, our results suggest that EID 1 is a bona fide substrate of FBXO 21 and that the control of EID 1 abundance by SCF FBXO 21 might affect the transcriptional repression activity of EID 1.