scholarly journals Btbd6-dependent Plzf recruitment to Cul3 E3 ligase complexes through BTB domain heterodimerization

2019 ◽  
Author(s):  
Mohamed Ismail ◽  
Stephen R. Martin ◽  
Neil J. Ball ◽  
Ian A. Taylor ◽  
Steven Howell ◽  
...  

AbstractThe Cul3 adaptor Btbd6 plays crucial roles in neural development by driving the ubiquitin-dependent degradation of promyelocytic zinc finger transcription factor (Plzf). Btbd6 has conserved motifs, BTB-BACK-PHR, and by analogy with other BTB-BACK adaptors, might be expected to bind to Cul3 through the BTB-BACK domain, and to substrate through the PHR domain. However, we now present a mode of adaptor-substrate interaction through heterodimerisation between the normally homodimeric BTB domains of Btbd6 and Plzf. This heterodimerization appears to occur through monomer exchange that is detected only at or near physiological concentrations. The Btbd6-Plzf heterodimer thus formed assembles into a ternary complex with Cul3. In addition we show that the BTB and PHR domains of Btbd6 promote localisation in the nucleus and that the BACK domain contains a nuclear export signal. Our findings support a model whereby Btbd6 moves into and out of the nucleus, iteratively ‘sweeping’ Plzf into the cytoplasm and enabling complex formation with Cul3 that presents Plzf for ubiquitination.HighlightsA general mechanism for recruitment of BTB domain-containing substrates by BTBdomain adaptors for the Cul3 E3 ligase complexNuclear export of the Plzf/Btbd6 complex mediated by a NES within the Btbd6 BACK domainCul3-dependent Plzf ubiquitylation through heterodimerisation of BTB domains on adaptor and substrate by monomer exchang

2011 ◽  
Vol 411 (5) ◽  
pp. 1114-1127 ◽  
Author(s):  
Mercedes Spínola-Amilibia ◽  
José Rivera ◽  
Miguel Ortiz-Lombardía ◽  
Antonio Romero ◽  
José L. Neira ◽  
...  

PLoS ONE ◽  
2014 ◽  
Vol 9 (3) ◽  
pp. e91953 ◽  
Author(s):  
Yawei Shi ◽  
Lei Zhang ◽  
Ting Yang

Virology ◽  
2001 ◽  
Vol 288 (1) ◽  
pp. 119-128 ◽  
Author(s):  
Lin Chen ◽  
Gangling Liao ◽  
Masahiro Fujimuro ◽  
O.John Semmes ◽  
S.Diane Hayward

2021 ◽  
Author(s):  
Xiaohui Xu ◽  
Han Wang ◽  
Jiqin Liu ◽  
Shuying Han ◽  
Miaomiao Lin ◽  
...  

Abstract Background: OsWRKY62 and OsWRKY76, two close members of WRKY transcription factors, function together as transcriptional repressors. OsWRKY62 is predominantly localized in the cytosol. What are the regulatory factors for OsWRKY62 nuclear translocation?Results: In this study, we characterized they interacted with rice importin, OsIMα1a and OsIMα1b, for nuclear translocation. Chimeric OsWRKY62.1-GFP, which is predominantly localized in the cytoplasm, was translocated to the nucleus of Nicotiana benthamiana leaf cells in the presence of OsIMα1a or OsIMαDIBB1a lacking the auto-inhibitory importin β-binding domain. OsIMαDIBB1a interacted with the WRKY domain of OsWRKY62.1, which has specific bipartite positively charged concatenated amino acids functioning as a nuclear localization signal. Similarly, we found that OsIMαDIBB1a interacted with the AvrPib effector of rice blast fungus Magnaporthe oryzae, which contains a scattered distribution of positively charged amino acids. Furthermore, we identified a nuclear export signal in OsWRKY62.1 that inhibited nuclear transportation. Overexpression of OsIMα1a or OsIMα1b enhanced resistance to M. oryzae, whereas knockout mutants decreased resistance to the pathogen. However, overexpressing both OsIMα1a and OsWRKY62.1 were slightly more susceptible to M. oryzae than OsWRKY62.1 alone. Ectopic overexpression of OsWRKY62.1 with an extra nuclear export signal compromised the enhanced susceptibility of OsWRKY62.1 to M. oryzae.Conclusion: These results indicated that OsWRKY62 localization is a consequence of competition binding between rice importins and exportins. OsWRKY62, OsWRKY76, and AvrPib effector translocate to nucleus in association with importin α1s through new types of nuclear localization signals for negatively regulating defense responses.


eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Ho Yee Joyce Fung ◽  
Szu-Chin Fu ◽  
Chad A Brautigam ◽  
Yuh Min Chook

The Chromosome Region of Maintenance 1 (CRM1) protein mediates nuclear export of hundreds of proteins through recognition of their nuclear export signals (NESs), which are highly variable in sequence and structure. The plasticity of the CRM1-NES interaction is not well understood, as there are many NES sequences that seem incompatible with structures of the NES-bound CRM1 groove. Crystal structures of CRM1 bound to two different NESs with unusual sequences showed the NES peptides binding the CRM1 groove in the opposite orientation (minus) to that of previously studied NESs (plus). Comparison of minus and plus NESs identified structural and sequence determinants for NES orientation. The binding of NESs to CRM1 in both orientations results in a large expansion in NES consensus patterns and therefore a corresponding expansion of potential NESs in the proteome.


EMBO Reports ◽  
2000 ◽  
Vol 1 (2) ◽  
pp. 176-182 ◽  
Author(s):  
Mina Watanabe ◽  
Norihisa Masuyama ◽  
Makoto Fukuda ◽  
Eisuke Nishida

2011 ◽  
Vol 434 (2) ◽  
pp. 253-263 ◽  
Author(s):  
Taras Valovka ◽  
Michael O. Hottiger

NF-κB (nuclear factor κB) controls diverse cellular processes and is frequently misregulated in chronic immune diseases or cancer. The activity of NF-κB is regulated by IκB (inhibitory κB) proteins which control nuclear–cytoplasmic shuttling and DNA binding of NF-κB. In the present paper, we describe a novel role for p65 as a critical regulator of the cellular localization and functions of NF-κB and its inhibitor IκBβ. In genetically modified p65−/− cells, the localization of ectopic p65 is not solely regulated by IκBα, but is largely dependent on the NLS (nuclear localization signal) and the NES (nuclear export signal) of p65. Furthermore, unlike IκBα, IκBβ does not contribute to the nuclear export of p65. In fact, the cellular localization and degradation of IκBβ is controlled by the p65-specific NLS and NES. The results of our present study also reveal that, in addition to stimulus-induced redistribution of NF-κB, changes in the constitutive localization of p65 and IκBβ specifically modulate activation of inflammatory genes. This is a consequence of differences in the DNA-binding activity and signal responsiveness between the nuclear and cytoplasmic NF-κB–IκBβ complexes. Taken together, the findings of the present study indicate that the p65 subunit controls transcriptional competence of NF-κB by regulating the NF-κB/IκBβ pathway.


2017 ◽  
Vol 45 (5) ◽  
pp. 2644-2657 ◽  
Author(s):  
Joris Pauty ◽  
Anthony M. Couturier ◽  
Amélie Rodrigue ◽  
Marie-Christine Caron ◽  
Yan Coulombe ◽  
...  

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