MyJournals Home  

RSS FeedsMulti-tiered pairing selectivity between E2 ubiquitin-conȷugating enzymes and E3 ligases [Signal Transduction] (Journal of Biological Chemistry)

 
 

21 october 2018 10:00:16

 
Multi-tiered pairing selectivity between E2 ubiquitin-conȷugating enzymes and E3 ligases [Signal Transduction] (Journal of Biological Chemistry)
 




Ubiquitination is a prevalent post-translational modification involved in all aspects of cell physiology. It is mediated by an enzymatic cascade and the E2 ubiquitin-conjugating enzymes (UBCs) lie at its heart. Even though E3 ubiquitin ligases determine the specificity of the reaction, E2s catalyze the attachment of ubiquitin and have emerged as key mediators of chain assembly. They are largely responsible for the type of linkage between ubiquitin moieties and thus, the fate endowed onto the modified substrate. However, in vivo E2-E3 pairing remains largely unexplored. We therefore interrogated the interaction selectivity between 37 Arabidopsis E2s and PUB22, a U-box type E3 ubiquitin ligase that is involved in the dampening of immune signaling. We show that whereas the U-box domain, which mediates E2 docking, is able to interact with 18 of 37 tested E2s, the substrate interacting armadillo (ARM) repeats impose a second layer of specificity, allowing the interaction with 11 E2s. In vitro activity assayed by autoubiquitination only partially recapitulated the in vivo selectivity. Moreover, in vivo pairing was modulated during the immune response; pairing with group VI UBC30 was inhibited, whereas interaction with the K63 chain-building UBC35 was increased. Functional analysis of ubc35 ubc36 mutants shows that they partially mimic pub22 pub23 pub24 enhanced activation of immune responses. Together, our work provides a framework to interrogate in vivo E2-E3 pairing and reveals a multi-tiered and dynamic E2-E3 network.


Del.icio.us Digg Facebook Google StumbleUpon Twitter
 
30 viewsCategory: Biochemistry
 
RNF144A sustains EGFR signaling to promote EGF-dependent cell proliferation [Protein Synthesis and Degradation] (Journal of Biological Chemistry)
Analysis of binding interfaces of the human scaffold protein AXIN1 by peptide microarrays [Signal Transduction] (Journal of Biological Chemistry)
 
 
blog comments powered by Disqus


MyJournals.org
The latest issues of all your favorite science journals on one page

Username:
Password:

Register | Retrieve

Search:

Biochemistry

Use these buttons to bookmark us:
Del.icio.us Digg Facebook Google StumbleUpon Twitter


Valid HTML 4.01 Transitional
Copyright © 2008 - 2018 Indigonet Services B.V.. Contact: Tim Hulsen. Read here our privacy notice.
Other websites of Indigonet Services B.V.: Nieuws Vacatures News Tweets Travel Photos Nachrichten Indigonet Finances Leer Mandarijn