摘要：
Ubiquitination is a fascinating post-translational modification that has received continuous attention since its discovery. In this review, we first provide a concise overview of the E3 ubiquitin ligases, delving into classification, characteristics and mechanisms of ubiquitination. We then specifically examine the ubiquitination pathways mediated by the N/C-degrons, discussing their unique features and substrate recognition mechanisms. Finally, we offer insights into the current state of development pertaining to inhibitors that target the N/C-degron pathways, as well as the promising advances in the field of PROTAC (PROteolysis TArgeting Chimeras). Overall, this review offers a comprehensive understanding of the rapidly-evolving field of ubiquitin biology.
期刊：
Journal of Biological Chemistry,2024年300(3):105776 ISSN：0021-9258
通讯作者：
Liu, Ke;Min, Jinrong
作者机构：
[Chen, Sizhuo; Lei, Ming] Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, PR China;[Liu, Ke] Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, PR China. Electronic address: keliu2015@ccnu.edu.cn;[Min, Jinrong] Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, PR China. Electronic address: minjinrong@ccnu.edu.cn
通讯机构：
[Liu, Ke; Min, Jinrong] H;Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, PR China. Electronic address:
摘要：
The CCAAT/enhancer-binding proteins (C/EBPs) constitute a family of pivotal transcription factors involved in tissue development, cellular function, proliferation, and differentiation. NFIL3, as one of them, plays an important role in regulating immune cell differentiation, circadian clock system and neural regeneration, yet its specific DNA recognition mechanism remains enigmatic. In this study, we showed by the ITC binding experiments that NFIL3 prefers to bind to the TTACGTAA DNA motif. Our structural studies revealed that the α-helical NFIL3 bZIP domain dimerizes through its leucine zipper region, and binds to DNA via its basic region. The two basic regions of the NFIL3 bZIP dimer were pushed apart upon binding to DNA, facilitating the snug accommodation of the two basic regions within the major grooves of the DNA. Remarkably, our binding and structural data also revealed that both NFIL3 and C/EBPα/β demonstrated a shared preference for the TTACGTAA sequence. Furthermore, our study revealed that disease-associated mutations within the NFIL3 bZIP domain resulted in either reduction or complete disruption of its DNA binding ability. These discoveries not only provide valuable insights into the DNA binding mechanisms of NFIL3 but also elucidate the causal role of NFIL3 mutations in disease pathogenesis.
摘要：
Nuclear respiratory factor 1 (NRF1) regulates the expression of genes that are vital for mitochondrial biogenesis, respiration, and various other cellular processes. While NRF1 has been reported to bind specifically to GC-rich promoters as a homodimer, the precise molecular mechanism governing its recognition of target gene promoters has remained elusive. To unravel the recognition mechanism, we have determined the crystal structure of the NRF1 homodimer bound to an ATGCGCATGCGCAT dsDNA. In this complex, NRF1 utilizes a flexible linker to connect its dimerization domain (DD) and DNA binding domain (DBD). This configuration allows one NRF1 monomer to adopt a U-turn conformation, facilitating the homodimer to specifically bind to the two TGCGC motifs in the GCGCATGCGC consensus sequence from opposite directions. Strikingly, while the NRF1 DBD alone could also bind to the half-site (TGCGC) DNA of the consensus sequence, the cooperativity between DD and DBD is essential for the binding of the intact GCGCATGCGC sequence and the transcriptional activity of NRF1. Taken together, our results elucidate the molecular mechanism by which NRF1 recognizes specific DNA sequences in the promoters to regulate gene expression. Graphical Abstract
作者机构：
[Cheng, Ying; Liao, Chongyu; Xiao, Yutao] Chinese Acad Agr Sci, Agr Genom Inst Shenzhen, Minist Agr,Genome Anal Lab, Shenzhen Branch,Guangdong Lab Lingnan Modern Agr, Shenzhen 518120, Peoples R China.;[Wu, Kongming; Zhang, Dandan] Chinese Acad Agr Sci, Inst Plant Protect, State Key Lab Biol Plant Dis & Insect Pests, Beijing 100089, Peoples R China.;[Liu, Kaiyu; Yang, Yongbo] Cent China Normal Univ, Coll Life Sci, Wuhan, Peoples R China.
通讯机构：
[Kongming Wu; Kongming Wu Kongming Wu Kongming Wu] T;[Yutao Xiao; Yutao Xiao Yutao Xiao Yutao Xiao] S;The State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China<&wdkj&>Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
摘要：
Evolution of resistance to Cry proteins in multiple pest insects has been threatening the sustainable use of Bacillus thuringiensis (Bt)-transgenic crops. Better understanding about the mechanism of resistance to Cry proteins in insects is needed. Our preliminary study reported that the transcription of HaABCC3 was significantly decreased in a near-isogenic line (LFC2) of a Cry1Ac-resistant strain (LF60) of the global pest Helicoverpa armigera. However, the causality between HaABCC3 down-regulation and resistance to Cry1Ac remains to be verified, and the regulatory mechanism underlying the HaABCC3 down-regulation is still unclear. In this study, our data showed that both HaABCC3 and HaABCC3 down-regulation were genetically linked to resistance to Cry1Ac in LF60. However, no InDels were observed in the coding sequence of HaABCC3 from LF60. Furthermore, F1 offspring from the cross of LF60 and a HaABCC2/3-knockout (KO) mutant exhibited moderate resistance to Cry1Ac toxin; this indicated that the high resistance to Cry1Ac toxin in LF60 may have resulted from multiple genetic factors, including HaABCC2 mis-splicing and HaABCC3 down-regulation. Results from luciferase reporter assays showed that promoter activity of HaABCC3 in LF60 was significantly lower than that in the susceptible strain, which indicated that HaABCC3 down-regulation was likely mediated by promoter variation. Consistently, multiple variations of the GATA- or FoxA-binding sites in the promoter region of HaABCC3 were identified. Collectively, all results in this study suggested that down-regulation of HaABCC3 observed in the H. armigera LF60 strain, that is resistant to Cry1Ac, may be mediated by a cis-regulatory mechanism. Down-regulation of HaABCC3 was genetically linked with resistance to Cry1Ac toxin. Offspring from cross of LF60 and HaABCC2/3-KO exhibited resistance to Cry1Ac toxin. Down-regulation of HaABCC3 was potentially mediated by cis-regulatory mechanism. This article is protected by copyright. All rights reserved.
作者机构：
[Li, Weifang; Zhang, Jin; Liu, Ke; Min, Jinrong; Xiao, Yuqing; Gan, Linyao] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.
通讯机构：
[Liu, K; Min, JR ] C;Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.
摘要：
The TFAP2 family regulates gene expression during differentiation, development, and organogenesis, and includes five homologs in humans. They all possess a highly conserved DNA binding domain (DBD) followed by a helix-span-helix (HSH) domain. The DBD-HSH tandem domain specifically binds to a GCC(N3)GGC consensus sequence, but the precise recognition mechanisms remain unclear. Here, we found that TFAP2 preferred binding to the GCC(N3)GGC sequence, and the pseudo-palindromic GCC and GGC motifs and the length of the central spacer between the two motifs determined their binding specificity. Structural studies revealed that the two flat amphipathic α-helical HSH domains of TFAP2A stacked with each other to form a dimer via hydrophobic interactions, while the stabilized loops from both DBD domains inserted into two neighboring major grooves of the DNA duplex to form base-specific interactions. This specific DNA binding mechanism controlled the length of the central spacer and determined the DNA sequence specificity of TFAP2. Mutations of the TFAP2 proteins are implicated in various diseases. We illustrated that reduction or disruption of the DNA binding ability of the TFAP2 proteins is the primary cause of TFAP2 mutation-associated diseases. Thus, our findings also offer valuable insights into the pathogenesis of disease-associated mutations in TFAP2 proteins.
作者：
Ke Liu;Jin Zhang;Yuqing Xiao;Ally Yang;Xiaosheng Song;...
期刊：
Journal of Biological Chemistry,2023年299(6):104734 ISSN：0021-9258
通讯作者：
Ke Liu<&wdkj&>Jinrong Min
作者机构：
[Ke Liu; Jin Zhang; Yuqing Xiao; Yunxia Chen] Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, PR China;[Ally Yang; Timothy R. Hughes] Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada;[Xiaosheng Song; Yanjun Li] Structural Genomics Consortium and Department of Physiology, University of Toronto, Toronto, Ontario, Canada;[Jinrong Min] Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, PR China<&wdkj&>Structural Genomics Consortium and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
通讯机构：
[Ke Liu; Jinrong Min] H;Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, PR China<&wdkj&>Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, PR China<&wdkj&>Structural Genomics Consortium and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
关键词：
BEN domain;BANP;BEND6;DNA methylation;X-ray crystallography
摘要：
The BEN domain-containing transcription factors regulate transcription by recruiting chromatin-modifying factors to specific chromatin regions via their DNA-binding BEN domains. The BEN domain of BANP has been shown to bind to a CGCG DNA sequence or an AAA-containing matrix attachment regions DNA sequence. Consistent with these in vivo observations, we identified an optimal DNA-binding sequence of AAATCTCG by protein binding microarray, which was also confirmed by our isothermal titration calorimetry and mutagenesis results. We then determined crystal structures of the BANP BEN domain in apo form and in complex with a CGCG-containing DNA, respectively, which revealed that the BANP BEN domain mainly used the electrostatic interactions to bind DNA with some base-specific interactions with the TC motifs. Our isothermal titration calorimetry results also showed that BANP bound to unmethylated and methylated DNAs with comparable binding affinities. Our complex structure of BANP-mCGCG revealed that the BANP BEN domain bound to the unmethylated and methylated DNAs in a similar mode and cytosine methylation did not get involved in binding, which is also consistent with our observations from the complex structures of the BEND6 BEN domain with the CGCG or CGmCG DNAs. Taken together, our results further elucidate the elements important for DNA recognition and transcriptional regulation by the BANP BEN domain-containing transcription factor.
作者机构：
[Yang, Yi-Wen; Chen, Si-Zhuo; Huang, Da; Qiu, Bao-Sheng; Yu, Chen; Liu, Ke; Qiu, BS] Cent China Normal Univ, Sch Life Sci, Wuhan 430079, Hubei, Peoples R China.;[Yang, Yi-Wen; Chen, Si-Zhuo; Huang, Da; Qiu, Bao-Sheng; Yu, Chen; Liu, Ke; Qiu, BS] Cent China Normal Univ, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Hubei, Peoples R China.;[Yang, Yi-Wen] Jiujiang Univ, Coll Pharm & Life Sci, Jiujiang 332000, Jiangxi, Peoples R China.;[Chen, Min] Univ Sydney, Sch Life & Environm Sci, Sydney, NSW 2006, Australia.
通讯机构：
[Chen, M ] U;[Qiu, BS ] C;Cent China Normal Univ, Sch Life Sci, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Hubei, Peoples R China.;Univ Sydney, Sch Life & Environm Sci, Sydney, NSW 2006, Australia.
摘要：
Expanded orange carotenoid protein paralogs in subaerial Nostoc species functionally specialize as singlet oxygen quenchers or phycobilisome fluorescence quenchers to survive desiccation tolerance. Orange carotenoid protein (OCP) is a photoactive protein that participates in the photoprotection of cyanobacteria. There are 2 full-length OCP proteins, 4 N-terminal paralogs (helical carotenoid protein [HCP]), and 1 C-terminal domain-like carotenoid protein (CCP) found in Nostoc flagelliforme, a desert cyanobacterium. All HCPs (HCP1 to 3 and HCP6) from N. flagelliforme demonstrated their excellent singlet oxygen quenching activities, in which HCP2 was the strongest singlet oxygen quencher compared with others. Two OCPs, OCPx1 and OCPx2, were not involved in singlet oxygen scavenging; instead, they functioned as phycobilisome fluorescence quenchers. The fast-acting OCPx1 showed more effective photoactivation and stronger phycobilisome fluorescence quenching compared with OCPx2, which behaved differently from all reported OCP paralogs. The resolved crystal structure and mutant analysis revealed that Trp111 and Met125 play essential roles in OCPx2, which is dominant and long acting. The resolved crystal structure of OCPx2 is maintained in a monomer state and showed more flexible regulation in energy quenching activities compared with the packed oligomer of OCPx1. The recombinant apo-CCP obtained the carotenoid pigment from holo-HCPs and holo-OCPx1 of N. flagelliforme. No such carotenoid transferring processes were observed between apo-CCP and holo-OCPx2. The close phylogenetic relationship of OCP paralogs from subaerial Nostoc species indicates an adaptive evolution toward development of photoprotection: protecting cellular metabolism against singlet oxygen damage using HCPs and against excess energy captured by active phycobilisomes using 2 different working modes of OCPx.
通讯机构：
[Qiu, BS ] C;Cent China Normal Univ, Sch Life Sci, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Hubei, Peoples R China.
摘要：
Hypothetical chloroplast open reading frames (ycfs) are putative genes in the plastid genomes of photosynthetic eukaryotes. Many ycfs are also conserved in the genomes of cyanobacteria, the presumptive ancestors of present-day chloroplasts. The functions of many ycfs are still unknown. Here, we generated knock-out mutants for ycf51 (sll1702) in the cyanobacterium Synechocystis sp. PCC 6803. The mutants showed reduced photoautotrophic growth due to impaired electron transport between photosystem II (PSII) and PSI. This phenotype results from greatly reduced PSI content in the ycf51 mutant. The ycf51 disruption had little effect on the transcription of genes encoding photosynthetic complex components and the stabilization of the PSI complex. In vitro and in vivo analyses demonstrated that Ycf51 cooperates with PSI assembly factor Ycf3 to mediate PSI assembly. Furthermore, Ycf51 interacts with the PSI subunit PsaC. Together with its specific localization in the thylakoid membrane and the stromal exposure of its hydrophilic region, our data suggest that Ycf51 is involved in PSI complex assembly. Ycf51 is conserved in all sequenced cyanobacteria, including the earliest branching cyanobacteria of the Gloeobacter genus, and is also present in the plastid genomes of glaucophytes. However, Ycf51 has been lost from other photosynthetic eukaryotic lineages. Thus, Ycf51 is a PSI assembly factor that has been functionally replaced during the evolution of oxygenic photosynthetic eukaryotes. Chloroplast reading frame Ycf51 is a photosystem I assembly factor conserved in all sequenced cyanobacteria and glaucophyte plastids but lost from other photosynthetic eukaryotic lineages.
作者机构：
[Zhang, Jin; Feng, Yingying; Chen, Sizhuo; Liu, Ke; Zhou, Mengqi; Min, Jinrong] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.
通讯机构：
[Jinrong Min; Ke Liu] H;Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, PR China<&wdkj&>Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, PR China
期刊：
Journal of Molecular Biology,2022年434(2):167404 ISSN：0022-2836
通讯作者：
Jinrong Min<&wdkj&>Ke Liu
作者机构：
[Li, Zhenhua; Chen, Sizhuo; Jia, Lingbo; Zhang, Xiyou; Wu, Zhibin; Liu, Ke; Zhou, Mengqi; Min, Jinrong] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.
通讯机构：
[Jinrong Min; Ke Liu] H;Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, PR China
关键词：
*5-methylcytosine DNA binding;*Arabidopsis thaliana;*DNA cytosine methylation;*MBD;*X-ray crystallography
期刊：
Applied and Environmental Microbiology,2022年88(7):e0250521 ISSN：0099-2240
通讯作者：
Xiao, YT;Liu, KY
作者机构：
[Xiao, Yutao; Cheng, Ying; Liao, Chongyu; Jin, Minghui] Chinese Acad Agr Sci, Agr Genom Inst Shenzhen, Shenzhen Branch,Minist Agr, Guangdong Lab Lingnan Modern Agr,Genome Anal Lab, Shenzhen, Peoples R China.;[Liu, Kaiyu; Yang, Yongbo] Cent China Normal Univ, Coll Life Sci, Wuhan, Peoples R China.;[Soberon, Mario; Bravo, Alejandra] Univ Nacl Autonoma Mexico, Inst Biotecnol, Cuernavaca, Morelos, Mexico.
通讯机构：
[Xiao, YT ; Liu, KY ] C;Chinese Acad Agr Sci, Agr Genom Inst Shenzhen, Shenzhen Branch,Minist Agr, Guangdong Lab Lingnan Modern Agr,Genome Anal Lab, Shenzhen, Peoples R China.;Cent China Normal Univ, Coll Life Sci, Wuhan, Peoples R China.
期刊：
Advances in Experimental Medicine and Biology,2022年1389:269-293 ISSN：0065-2598
通讯作者：
Min, J.
作者机构：
[Min J.; Song X.; Liu K.] Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, China;[Wade P.A.; Shimbo T.] Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, Durham, NC, United States
通讯机构：
[Min, J.] H;Hubei Key Laboratory of Genetic Regulation and Integrative Biology, China
关键词：
DNA methylation;Epigenetics;MBD;Methylcytosine-binding proteins (MBPs)
期刊：
Current Opinion in Chemical Biology,2021年63:105-114 ISSN：1367-5931
通讯作者：
Min, Jinrong;Liu, Ke
作者机构：
[Liu, Ke; Min, Jinrong] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.;[Min, Jinrong] Univ Toronto, Struct Genom Consortium, Toronto, ON M5G 1L7, Canada.;[Min, Jinrong] Univ Toronto, Dept Physiol, Toronto, ON M5S 1A8, Canada.
通讯机构：
[Jinrong Min; Ke Liu] H;Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, PR China<&wdkj&>Structural Genomics Consortium, University of Toronto, Toronto, Ontario, M5G 1L7, Canada<&wdkj&>Department of Physiology, University of Toronto, Toronto, Ontario, M5S 1A8, Canada<&wdkj&>Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, PR China
作者机构：
[Yan, Lin; Zhao, Jingyan; Peng, Jianxin; Liu, Kaiyu; Yan, Xiumei; Yang, Yongbo; Ma, Haihao; Song, Jiping; Peng, Rong] Cent China Normal Univ, Sch Life Sci, Wuhan 430079, Peoples R China.
通讯机构：
[Peng, JX; Liu, KY] C;Cent China Normal Univ, Sch Life Sci, Wuhan 430079, Peoples R China.
关键词：
Apaf-1;apoptosis;caspase;Spodoptera litura
摘要：
Simple Summary Apoptosis plays an important role in both the development of lepidopteran insects and the elimination of cells. The apoptosis signal pathways are well documented in mammals and Drosophila melanogaster. However, it remains less clear in lepidopteran insects. This study characterized the apoptotic protease activating factor-1 (Apaf-1) from Spodoptera litura. The results showed that S. litura Apaf-1 (Sl-Apaf-1) is similar to the mammalian Apaf-1. Sl-Apaf-1 consists of a caspase recruitment domain (CARD), as well as nucleotide-binding and oligomerization domain (NOD) and the C-terminal WD40-repeat domain (WD), and interacts with Sl-caspase-5 (a homologue of mammalian caspase-9). The activated Sl-caspase-5 can cleave Sl-procaspase-1 (a homologue of caspase-3 in mammals), which directly causes apoptosis. The apoptosis signal pathway is conserved between lepidopteran insects and mammals. Apoptotic protease activating factor-1 (Apaf-1) is an adaptor molecule, essential for activating initiator caspase and downstream effector caspases, which directly cause apoptosis. In fruit flies, nematodes, and mammals, Apaf-1 has been extensively studied. However, the structure and function of Apaf-1 in Lepidoptera remain unclear. This study identified a novel Apaf-1 from Spodoptera litura, named Sl-Apaf-1. Sl-Apaf-1 contains three domains: a CARD domain, as well as NOD and WD motifs, and is very similar to mammalian Apaf-1. Interference of Sl-apaf-1 expression in SL-1 cells blocked apoptosis induced by actinomycin D. Overexpression of Sl-apaf-1 significantly enhances apoptosis induced by actinomycin D in Sf9/SL-1/U2OS cells, suggesting that the function of Sl-Apaf-1 is evolutionarily conserved. Furthermore, Sl-Apaf-1 could interact with Sl-caspase-5 (a homologue of mammalian caspase-9) and yielded a binding affinity of 1.37 x 10(6) M-1 according isothermal titration calorimetry assay. Initiator caspase (procaspase-5) of S. litura could be activated by Sl-Apaf-1 (without WD motif) in vitro, and the activated Sl-caspase-5 could cleave Sl-procaspase-1 (a homologue of caspase-3 in mammals), which directly caused apoptosis. This study demonstrates the key role of Sl-Apaf-1 in the apoptosis pathway, suggesting that the apoptosis pathway in Lepidopteran insects and mammals is conserved.
作者机构：
[Yong, Yu-Le; Lin, Peng; Liu, Man; Zheng, Nai-Shan; Li, Hao; Zhang, Ren-Yu; Chen, Zhi-Nan; Bian, Huijie; Liu, Ze-Kun; Wei, Ding] Fourth Mil Med Univ, Natl Translat Sci Ctr Mol Med, Dept Cell Biol, Xian 710032, Peoples R China.;[Liu, Ke] Cent China Normal Univ, Sch Life Sci, Wuhan 430079, Peoples R China.;[Yang, Xiao-Zhen; Hu, Cai-Xia] Capital Med Univ, Beijing Youan Hosp, Oncol & Hepatobiliary Minimally Invas Intervent C, Beijing 100069, Peoples R China.
通讯机构：
[Chen, ZN; Bian, HJ] F;Fourth Mil Med Univ, Natl Translat Sci Ctr Mol Med, Dept Cell Biol, Xian 710032, Peoples R China.
摘要：
Genomic sequencing analysis of tumors provides potential molecular therapeutic targets for precision medicine. However, identifying a key driver gene or mutation that can be used for hepatocellular carcinoma (HCC) treatment remains difficult. Here, we performed whole-exome sequencing on genomic DNA obtained from six pairs of HCC and adjacent tissues and identified two novel somatic mutations of UBE2S (p. Gly57Ala and p. Lys63Asn). Predictions of the functional effects of the mutations showed that two amino-acid substitutions were potentially deleterious. Further, we observed that wild-type UBE2S, especially in the nucleus, was significantly higher in HCC tissues than that in adjacent tissues and closely related to the clinicopathological features of patients with HCC. Functional assays revealed that overexpression of UBE2S promoted the proliferation, invasion, metastasis, and G1/S phase transition of HCC cells in vitro, and promoted the tumor growth significantly in vivo. Mechanistically, UBE2S interacted with TRIM28 in the nucleus, both together enhanced the ubiquitination of p27 to facilitate its degradation and cell cycle progression. Most importantly, the small-molecule cephalomannine was found by a luciferase-based sensitive high-throughput screen (HTS) to inhibit UBE2S expression and significantly attenuate HCC progression in vitro and in vivo, which may represent a promising strategy for HCC therapy.
期刊：
Insect Biochemistry and Molecular Biology,2021年135:103608 ISSN：0965-1748
通讯作者：
Xiao, Yutao;Liu, Kaiyu
作者机构：
[Xia, Zhichao; Liu, Kaiyu; Wang, Haixia; Liu, Yuanyuan; Yang, Yongbo] Cent China Normal Univ, Sch Life Sci, Inst Entomol, Wuhan 430079, Peoples R China.;[Xiao, Yutao; Jin, Minghui] Chinese Acad Agr Sci, Agr Genom Inst Shenzhen, Shenzhen 518120, Peoples R China.;[Wang, Ling] Hubei Acad Agr Sci, Inst Plant Protect & Soil Fertil, Minist Agr,Hubei Key Lab Crop Dis Insect Pests &, Key Lab Integrated Pest Management Crops Cent Chi, Wuhan 430064, Peoples R China.;[Soberon, Mario; Bravo, Alejandra] Univ Nacl Autonoma Mexico, Inst Biotecnol, Apdo Postal 510-3, Cuernavaca 62250, Morelos, Mexico.
通讯机构：
[Xiao, Yutao] A;[Liu, Kaiyu] I;Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518120, China. Electronic address:;Institute of Entomology, School of Life Sciences, Central China Normal University, Wuhan, 430079, PR China. Electronic address:
摘要：
Bacillus thuringiensis (Bt) bacteria produce Cry toxins that kill insect pests. Insect specificity of Cry toxins relies on their binding to larval gut membrane proteins such as cadherin and ATP-binding cassette (ABC) transporter proteins. Mutations in ABC transporters have been implicated in high levels of resistance to Cry toxins in multiple pests. Spodoptera frugiperda is an insect pest susceptible to Cry1Fa and Cry1Ab toxins while Mythimna separata is tolerant to Cry1Fa and less susceptible to Cry1Ab. Here, we analyzed the potential role of ABCC2 in determining the susceptibility of S. frugiperda to Cry1Fa and Cry1Ab, by expressing SfABCC2 or MsABCC2 in Hi5 insect cell line and by the systematic replacements of extracellular loops (ECLs) between these two proteins. Expression of SfABCC2 in Hi5 conferred susceptibility to both Cry1Fa and Cry1Ab, in contrast to the expression of MsABCC2 that mediated low toxicity to Cry1Ab and no toxicity to Cry1Fa in agreement with their larvicidal toxicities. The SfABCC2 and MsABCC2 amino acid sequences showed differential residues among ECL1, ECL2, ECL4 and ECL6 loops, while ECL3 and ECL5 share the same primary sequence. The exchange of ECLs between SfABCC2 and MsABCC2 demonstrated that ECL4 and ECL2 contribute to Cry1Fa toxicity, where ECL4 plays a major role. The medium region (named M2) of ECL4 was identified as the most important region of SfABCC2 involved in Cry1Fa toxicity as shown by point mutations in this region. These findings will be helpful to understand the mechanisms of action of Bt toxins in S. frugiperda.
