Small extracellular ring domain is necessary for CD82/KAI1′anti-metastasis function

2021 ◽  
Vol 557 ◽  
pp. 110-116
Author(s):  
Xiaoguang Ma ◽  
Xin He ◽  
Congcong Wang ◽  
Xiaohua Huang ◽  
Ying Li ◽  
...  
Keyword(s):  
Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 254
Author(s):  
Zi-Hao Wang ◽  
Fei Ke ◽  
Qi-Ya Zhang ◽  
Jian-Fang Gui

Carassius auratus herpesvirus (CaHV) has been identified as a high-virulence pathogenic virus that infects aquatic animals, but the key factor for virus–host interaction is still unclear. Five Really interesting new genes (RING) finger proteins (39L, 52L, 131R, 136L, and 143R) of CaHV were screened to determine structural diversity. RING finger proteins were also predicted in other known fish herpesviruses, with an arrangement and number similar to CaHV. We performed multifaceted analyses of the proteins, including protein sizes, skeleton structures, subcellular localizations, and ubiquitination activities, to determine their precise roles in virus–host interactions. The five proteins were overexpressed and detected different levels of ubiquitination activities, and 143R showed the highest activity. Then, the prokaryotic expressed and purified full-length proteins (131R and 136L), RING domain isolates (131R12–43 and 136L45–87), and RING domain-deleted mutants (131RΔ12–43 and 136LΔ45–87) were prepared to detect their activities through ubiquitination assays. The results indicate that both full-length proteins and their isolates have activities that catalyze ubiquitination, and the full-length proteins possess higher activity than the isolates, but RING domain-deleted mutants lose their activities. Furthermore, the activities of the five proteins were verified as E3 ubiquitin ligase activity, showing that the RING domains determine the ubiquitination activity. These proteins present different subcellular localization. RING domain-deleted mutants showed similar subcellular localization with their full-length proteins, and all the isolates diffused in whole cells. The current results indicate that the sequence outside the RING domain determines subcellular localization and the level of ubiquitination activity, suggesting that the RING finger proteins of fish herpesviruses might have diverse functions in virus–host interaction.


2008 ◽  
Vol 283 (36) ◽  
pp. 24871-24880 ◽  
Author(s):  
Betty Lamothe ◽  
Alejandro D. Campos ◽  
William K. Webster ◽  
Ambily Gopinathan ◽  
Lana Hur ◽  
...  

2007 ◽  
Vol 18 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Cosimo Commisso ◽  
Gabrielle L. Boulianne

Notch signaling, which is crucial to metazoan development, requires endocytosis of Notch ligands, such as Delta and Serrate. Neuralized is a plasma membrane-associated ubiquitin ligase that is required for neural development and Delta internalization. Neuralized is comprised of three domains that include a C-terminal RING domain and two neuralized homology repeat (NHR) domains. All three domains are conserved between organisms, suggesting that these regions of Neuralized are functionally important. Although the Neuralized RING domain has been shown to be required for Delta ubiquitination, the function of the NHR domains remains elusive. Here we show that neuralized1, a well-characterized neurogenic allele, exhibits a mutation in a conserved residue of the NHR1 domain that results in mislocalization of Neuralized and defects in Delta binding and internalization. Furthermore, we describe a novel isoform of Neuralized and show that it is recruited to the plasma membrane by Delta and that this is mediated by the NHR1 domain. Finally, we show that the NHR1 domain of Neuralized is both necessary and sufficient to bind Delta. Altogether, our data demonstrate that NHR domains can function in facilitating protein–protein interactions and in the case of Neuralized, mediate binding to its ubiquitination target, Delta.


2008 ◽  
Vol 19 (7) ◽  
pp. 2729-2740 ◽  
Author(s):  
Herman H. Cheung ◽  
Stéphanie Plenchette ◽  
Chris J. Kern ◽  
Douglas J. Mahoney ◽  
Robert G. Korneluk

The Inhibitor of Apoptosis proteins (IAPs) are key repressors of apoptosis. Several IAP proteins contain a RING domain that functions as an E3 ubiquitin ligase involved in the ubiquitin-proteasome pathway. Here we investigated the interplay of ubiquitin-proteasome pathway and RING-mediated IAP turnover. We found that the CARD-RING domain of cIAP1 (cIAP1-CR) is capable of down-regulating protein levels of RING-bearing IAPs such as cIAP1, cIAP2, XIAP, and Livin, while sparing NAIP and Survivin, which do not possess a RING domain. To determine whether polyubiquitination was required, we tested the ability of cIAP1-CR to degrade IAPs under conditions that impair ubiquitination modifications. Remarkably, although the ablation of E1 ubiquitin-activating enzyme prevented cIAP1-CR–mediated down-regulation of cIAP1 and cIAP2, there was no impact on degradation of XIAP and Livin. XIAP mutants that were not ubiquitinated in vivo were readily down-regulated by cIAP1-CR. Moreover, XIAP degradation in response to cisplatin and doxorubicin was largely prevented in cIAP1-silenced cells, despite cIAP2 up-regulation. The knockdown of cIAP1 and cIAP2 partially blunted Fas ligand-mediated down-regulation of XIAP and protected cells from cell death. Together, these results show that the E3 ligase RING domain of cIAP1 targets RING-bearing IAPs for proteasomal degradation by ubiquitin-dependent and -independent pathways.


2012 ◽  
Vol 26 (S1) ◽  
Author(s):  
Robert D Wardlow ◽  
Sung Hee Choi ◽  
Brian McMillan ◽  
Stephen C Blacklow

2018 ◽  
Vol 115 (6) ◽  
pp. 1316-1321 ◽  
Author(s):  
Mikaela D. Stewart ◽  
Elena Zelin ◽  
Abhinav Dhall ◽  
Tom Walsh ◽  
Esha Upadhyay ◽  
...  

Missense mutations that disrupt the RING domain of the tumor suppressor gene BRCA1 lead to increased risk of breast and ovarian cancer. The BRCA1 RING domain is a ubiquitin ligase, whose structure and function rely critically on forming a heterodimer with BARD1, which also harbors a RING domain. The function of the BARD1 RING domain is unknown. In families severely affected with breast cancer, we identified inherited BARD1 missense mutations Cys53Trp, Cys71Tyr, and Cys83Arg that alter three zinc-binding residues of the BARD1 RING domain. Each of these mutant BARD1 proteins retained the ability to form heterodimeric complexes with BRCA1 to make an active ubiquitin ligase, but the mutant BRCA1/BARD1 complexes were deficient in binding to nucleosomes and in ubiquitylating histone H2A. The BARD1 mutations also caused loss of transcriptional repression of BRCA1-regulated estrogen metabolism genes CYP1A1 and CYP3A4; breast epithelial cells edited to create heterozygous loss of BARD1 showed significantly higher expression of CYP1A1 and CYP3A4. Reintroduction of wild-type BARD1 into these cells restored CYP1A1 and CYP3A4 transcription to normal levels, but introduction of the cancer-predisposing BARD1 RING mutants failed to do so. These results indicate that an intact BARD1 RING domain is critical to BRCA1/BARD1 binding to nucleosomes and hence to ubiquitylation of histone H2A and also critical to transcriptional repression of BRCA1-regulated genes active in estrogen metabolism.


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