Discovery of Ureido-Based Apcin Analogues as Cdc20-specific Inhibitors against Cancer.

Cdc20 is a promising drug target that plays an important role in the mid-anaphase process of cellular mitosis, and Apcin is the only reported core structure of the Cdc20-specific inhibitor. Some potent Apcin derivatives were obtained in our previous research, and a structure-activity relationship was determined. In this study, we designed and synthesized a series of ureido-based Apcin derivatives. The proliferation-inhibition experiments on four cancer-cell lines showed that ureido skeleton could promote the anti-proliferation activity of purine-substituted compounds, whereas the ureido analogues with pyrimidine substitutes showed no significant improvement in the inhibitory effect compared with the original ones. Further tests confirmed that ureido-based compounds can enhance the binding affinity to Cdc20 by increasing the levels of Cdc20 downstream proteins. Compound 27 revealed a remarkably antitumor activity pattern against Hela (IC50 = 0.06 ± 0.02 µM) and potent binding affinity to Cdc20. Moreover, compound 20 induced caspase-dependent apoptosis and cell-cycle arrest at the G2/M phase, and compound 27 induced caspase-dependent apoptosis and promoted microtubule polymerization. Finally, a molecular-docking simulation was performed for compounds 20 and 27 to predict the potential ligand-protein interactions with the active sites of the Cdc20 proteins.

Genome-wide characterization of the C2H2 zinc-finger genes in Cucumis sativus and functional analyses of four CsZFPs in response to stresses.

BACKGROUNDS: C2H2-type zinc finger protein (ZFPs) form a relatively large family of transcriptional regulators in plants, and play many roles in plant growth, development, and stress response. However, the comprehensive analysis of C2H2 ZFPs in cucumber (CsZFPs) and their regulation function in cucumber are still lacking. RESULTS: In the current study, the whole genome identification and characterization of CsZFPs, including the gene structure, genome localization, phylogenetic relationship, and gene expression were performed. Functional analysis of 4 selected genes by transient transformation were also conducted. A total of 129 full-length CsZFPs were identified, which could be classified into four groups according to the phylogenetic analysis. The 129 CsZFPs unequally distributed on 7 chromosomes. Promoter cis-element analysis showed that the CsZFPs might involve in the regulation of phytohormone and/or abiotic stress response, and 93 CsZFPs were predicted to be targeted by one to 20 miRNAs. Moreover, the subcellular localization analysis indicated that 10 tested CsZFPs located in the nucleus and the transcriptome profiling analysis of CsZFPs demonstrated that these genes are involved in root and floral development, pollination and fruit spine. Furthermore, the transient overexpression of Csa1G085390 and Csa7G071440 into Nicotiana benthamiana plants revealed that they could decrease and induce leave necrosis in response to pathogen attack, respectively, and they could enhance salt and drought stresses through the initial induction of H2O2. In addition, Csa4G642460 and Csa6G303740 could induce cell death after 5 days transformation. CONCLUSIONS: The identification and function analysis of CsZFPs demonstrated that some key individual CsZFPs might play essential roles in response to biotic and abiotic stresses. These results could lay the foundation for understanding the role of CsZFPs in cucumber development for future genetic engineering studies.

Genome-wide identification, characterization analysis and expression profiling of auxin-responsive GH3 family genes in wheat (Triticum aestivum L.).

Auxin affects many aspects of plant growth and development by regulating the expression of auxin-responsive genes. As one of the three major auxin-responsive families the Gretchen Hagen3 (GH3) gene family maintains hormonal homeostasis by conjugating excess indole-3-acetic acid (IAA), salicylic acid (SA), and jasmonic acid (JA) to amino acids during hormone and stress-related signaling. Although some work has been carried out the functions of wheat GH3 (TaGH3) family genes in response to abiotic stresses (including salt stress and osmotic stress) are largely unknown. Access to the complete wheat genome sequence permits genome-wide studies on TaGH3s. We performed a systematic identification of the TaGH3 gene family at the genome level and detected 36 members on 14 wheat chromosomes. Many of the genes were segmentally duplicated and Ka/Ks and inter-species synthetic analyses indicated that polyploidization was the contributor to the increased number of TaGH3 members. Phylogenetic analyses revealed that TaGH3 proteins could divided into three major categories (TaGH3-I, TaGH3-II, and TaGH3-III). Diversified cis-elements in the promoters of TaGH3 genes were predicted as essential players in regulating TaGH3 expression patterns. Gene structure and motif analyses indicated that most TaGH3 genes have relatively conserved exon/intron arrangements and motif compositions. Analysis of multiple transcriptome data sets indicated that many TaGH3 genes are responsive to biological and abiotic stresses and possibly have important functions in stress response. qRT-PCR analysis revealed that TaGH3s were induced by salt and osmotic stresses. Customized annotation results revealed that TaGH3s were widely involved in phytohormone response, defense, growth and development, and metabolism. Overall, our work provides a comprehensive insight into the TaGH3 family members, and a basis for the further study of their biological functions in wheat.

Genome-wide identification, structure characterization, and expression pattern profiling of aquaporin gene family in cucumber.

BACKGROUND: Aquaporin (AQP) proteins comprise a group of membrane intrinsic proteins (MIPs) that are responsible for transporting water and other small molecules, which is crucial for plant survival under stress conditions including salt stress. Despite the vital role of AQPs, little is known about them in cucumber (Cucumis sativus L.). RESULTS: In this study, we identified 39 aquaporin-encoding genes in cucumber that were separated by phylogenetic analysis into five sub-families (PIP, TIP, NIP, SIP, and XIP). Their substrate specificity was then assessed based on key amino acid residues such as the aromatic/Arginine (ar/R) selectivity filter, Froger's positions, and specificity-determining positions. The putative cis-regulatory motifs available in the promoter region of each AQP gene were analyzed and results revealed that their promoter regions contain many abiotic related cis-regulatory elements. Furthermore, analysis of previously released RNA-seq data revealed tissue- and treatment-specific expression patterns of cucumber AQP genes (CsAQPs). Three aquaporins (CsTIP1;1, CsPIP2;4, and CsPIP1;2) were the most transcript abundance genes, with CsTIP1;1 showing the highest expression levels among all aquaporins. Subcellular localization analysis in Nicotiana benthamiana epidermal cells revealed the diverse and broad array of sub-cellular localizations of CsAQPs. We then performed RNA-seq to identify the expression pattern of CsAQPs under salt stress and found a general decreased expression level of root CsAQPs. Moreover, qRT-PCR revealed rapid changes in the expression levels of CsAQPs in response to diverse abiotic stresses including salt, polyethylene glycol (PEG)-6000, heat, and chilling stresses. Additionally, transient expression of AQPs in N. benthamiana increased leaf water loss rate, suggesting their potential roles in the regulation of plant water status under stress conditions. CONCLUSIONS: Our results indicated that CsAQPs play important roles in response to salt stress. The genome-wide identification and primary function characterization of cucumber aquaporins provides insight to elucidate the complexity of the AQP gene family and their biological functions in cucumber.