Diagnostic value of methylated branched chain amino acid transaminase 1/IKAROS family zinc finger 1 for colorectal cancer

BACKGROUND The diagnostic value of combined methylated branched chain amino acid transaminase 1(BCAT1)/IKAROS family zinc finger 1(IKZF1)in plasma for colorectal cancer(CRC)has been explored since 2015.Recently,several related studies have published their results and showed its diagnostic efficacy.AIM To analyze the diagnostic value of methylated BCAT1/IKZF1 in plasma for screening and postoperative follow-up of CRC.METHODS The candidate studies were identified by searching the PubMed,Embase,Cochrane Library,CNKI,and Wanfang databases from May 31,2003 to June 1,2023.Sensitivity,specificity,and diagnostic accuracy were calculated by merging ratios or means.RESULTS Twelve eligible studies were included in the analysis,involving 6561 participants.The sensitivity of methylated BCAT1/IKZF1 in plasma for CRC diagnosis was 60%[95%confidence interval(CI)53-67]and specificity was 92%(95%CI:90-94).The positive and negative likelihood ratios were 8.0(95%CI:5.8-11.0)and 0.43(95%CI:0.36-0.52),respectively.Diagnostic odds ratio was 19(95%CI:11-30)and area under the curve was 0.88(95%CI:0.85-0.91).The sensitivity and specificity for CRC screening were 64%(95%CI:59-69)and 92%(95%CI:91-93),respectively.The sensitivity and specificity for recurrence detection during follow-up were 54%CONCLUSION The detection of methylated BCAT1/IKZF1 in plasma,as a non-invasive detection method of circulating tumor DNA,has potential CRC diagnosis,but the clinical application prospect needs to be further explored.

Myeloid zinc finger 1(MZF1) is the most important transcriptional factor for porcine follistatin promoter

Follistatin （FS） is a secreted protein, which was originally isolated from porcine follicular fluid. Expression of follistatin is tightly regulated during porcine growth and development. To study the essential transcriptional regions of the porcine FS promoter, ten primer pairs were designed to amplify segments with different lengths of the FS promoter from -1 800 to ＋16 bp. The products were then inserted into the pGL3-basic vector to analyze the relative luciferase activity. The results showed that the most remarkable changes of promoter activity were observed between constructs （-302/＋16 bp）-FS and （-180/＋16 bp）-FS （P〈0.01）. Further research showed that the reconstructed reporter plasmid lacking myeloid zinc finger 1 （MZF1） binding sequence had significantly decreased luciferase activity （P〈0.05）. Furthermore, the FS protein expression was significantly increased in PK15 cells while the MZF1 was overexpressed, suggesting that the short sequence ＂TCCCCACC＂ （the recognition site of transcription factor MZF1） was the most important for FS transcription activation in the porcine.

Genome-wide analysis of the CCCH zinc finger family in longan:Characteristic identification and expression profiles in Dimocarpus longan Lour

CCCH(C3 H) Zinc finger(Znf) transcription factors(TFs), as a novel type of Znf gene, regulate the expression of genes by binding to their mRNAs and play important roles in plant growth and development and abiotic stress resistance.Longan(Dimocarpous longan) is a tropical/subtropical fruit tree of great economic importance in Southeast Asia.However, genomic information on C3 H and their functions in longan are still unknown. In this study, a comprehensive analysis of the longan C3 H(DlC3 H) gene family was carried out. A total of 49 DlC3 H genes in three clades were identified from the longan genome database. Characteristics of the genes were analyzed with respect to gene structure,motif composition, phylogenetic tree and potential functions. The analysis of alternative splicing(AS) events suggested that AS events in DlC3 H genes were related to the transformation from longan non-embryonic to embryonic cultures.Promoter analysis indicated that most of the DlC3 H genes included cis-acting elements associated with hormones and stresses responses. Quantitative real-time PCR(qRT-PCR) analysis indicated that 26 of the 49 DlC3 Hs, which possess methyl jasmonate(MeJA) and abscisic acid(ABA) responsive cis-acting elements, showed differential expression patterns under treatment with ABA, MeJA and their endogenous inhibitors, suggesting that DlC3 Hs might be involved in the ABA and MeJA signaling pathways. The expression profiles of 17 of the 49 DlC3 Hs in non-embryonic callus and three tissues of embryonic cultures showed that only five of the 17 DlC3 Hs had the same expression trends as the FPKM trends in transcriptome data;the expression levels of DlC3 H07/14/16/36/49 in embryogenic callus and DlC3 H04/38 in globular embryos were high, suggesting that they have different functions in embryonic development. Further, we verified that DlC3 H01/03/05/11/19/39 were regulated by sRNAs by a modified 5’ RLM-RACE method. This study provides the first systematic analysis of C3 H genes in longan, and found that C3 H genes may be involved in hormone and stress responses, and somatic embryogenesis. Our preliminary investigation may provide clues to further studies on the characteristics and functions of this family in longan.

Expression Pattern Analysis of Zinc Finger Protein Genes in Wheat(Triticum aestivum L.) Under Phosphorus Deprivation

Zinc finger protein（ZFP） genes comprise a large and diverse gene family, and are involved in biotic and abiotic stress responses in plants. In this study, a total of 126 ZFP genes classified into various types in wheat were characterized and subjected to expression pattern analysis under inorganic phosphate（Pi） deprivation. The wheat ZFP genes and their corresponding GenBank numbers were obtained from the information of a 4×44K wheat gene expression microarray chip. They were confirmed by sequence similarity analysis and named based on their homologs in Brachypodium distachyon or Oriza sativa. Expression analysis based on the microarray chip revealed that these ZFP genes are categorized into 11 classes according to their gene expression patterns in a 24-h of Pi deprivation regime. Among them, ten genes were differentially up-regulated, ten genes differentially downregulated, and two genes both differentially up- and down-regulated by Pi deprivation. The differentially up- or down-regulated genes exhibited significantly more or less transcripts at one, two, or all of the checking time points（1, 6, and 24 h） of Pi stress in comparison with those of normal growth, respectively. The both differentially up- and down-regulated genes exhibited contrasting expression patterns, of these, TaWRKY70;5 showed significantly up-regulated at 1 and 6 h and down-regulated at 24 h whereas TaAN1AN20-8;2 displayed significantly upregulated at 1 h and downregulated at 6 h under deprivation Pi condition. Real time PCR analysis confirmed the expression patterns of the differentially expressed genes obtained by the microarray chip. Our results indicate that numerous ZFP genes in wheat respond to Pi deprivation and have provided further insight into the molecular basis that plants respond to Pi deprivation mediated by the ZFP gene family.

STUDIES ON THE SYNTHESIS AND DNA-BINDING ABILITY OF ZINC FINGER MOTIF

Transcription factor SPI is a protcin present in mammalian cells that binds to GC box promoter clements of Gene and selectively activates mRNA synthesis. The gene contains functional recognition sites. It contains three continuous zinc finger motifs, which are believed being mctalloprotein structures that interact with DNA. We synthesized the second zine finger fragment of SP1 (SP1-ZF2) and its mutant (SP1-ZF2 / HT. E20→H. R23→T), we also synthesized the Cys-Cys loop (ZF6) and the His-His loop (ZF5) of SPI and linked the twoloops together using a β-turn structure to obtain a finger mimic analogue (ZF-15) by stepwise solid-phase technique. Atomic absorption studies show that SP 1-ZF2 and SP1-ZF2 / HT bind zinc cquimolarly, but ZF-15 docs not bind Zn anyway. The CD experiments demonstrate a significant change in secondary structure in the prescnce or absence of Zn to SP1-ZF2 and SP1-ZF2/ HT, but there is no change about ZF-15. Gcl-retardation clectrophoresis assays indicate that SP1-ZF2 binds to DNA sequence specifically in the presence of Zn, but SP1-ZF2 / HT docs not bind as SP 1-ZF2 did. We observed that a single zine finger like SP1-ZF2 is able to bind DNA sequence specifically.

Molecular Cloning and Expression Analysis of a Cys2/His2 Type Zinc Finger Protein Gene in Upland Cotton

The zinc finger proteins belong to the largest family of transcription factors.But there is little research of Cys2/His2 type zinc finger proteins in cotton,and there is no submission of correlating

Molecular Characterization and Expression Analysis of TaZFP15, a C_2H_2-Type Zinc Finger Transcription Factor Gene in Wheat (Triticum aestivum L.)

Based on sequencing of part clones in a root subtractive cDNA library, an expressed sequence tag （EST） sharing high similarity to a rice C2H2 zinc finger transcription factor （ZFP15） was obtained in wheat. Through bioinformatics approach, the wheat C2H2-type ZFP gene referred to TaZFP15 has been identified and characterized. As a full-length cDNA of 670 bp, TaZFP15 has an open reading frame of 408 bp and encodes a 135-aa polypeptide. TaZFP15 contains two C2H2 zinc finger domains and each one has a conserved motif QALGGH. The typical L-box, generally identified in the C2H2 type transcription factors, has also been found in TaZFP15. Phylogenetic analysis suggested that TaZFP15 shares high similarities with rice ZFP15 （GenBank accession no. AY286473）, maize ZFP （GenBank accession no. NM_001159094） and a subset of other zinc-finger transcription factor genes in plant species. The expression of TaZFP15 was up-regulated by starved-Pi stress, showing a pattern to be gradually elevated along with the progression of the Pi-stress in a 23-h treatment regime. Similarly, the transcripts of TaZFP15 in roots were also induced by nitrogen deficiency, and abiotic stresses of drought and salinity. No responses of TaZFP15 were detected in roots to nutrition deficiencies of P, Zn, and Ca, and the external treatment of abscisic acid （ABA）. TaZFP15 could be specifically amplified in genome A, B, and D, and without variability in the sequences, suggesting that TaZFP15 has multi-copies in the homologous hexaploid species. Transgenic analysis in tobacco revealed that up-regulation of TaZFP15 could significantly improve plant dry mass accumulation via increasing the plant phosphorus acquisition capacity under Pi-deficiency condition. The results suggested that TaZFP15 is involved in mediation of signal transductions of diverse external stresses.

Zinc finger protein A20 protects rats against chronic liver allograft dysfunction

AIM:To investigate the effect of zinc finger protein A20 on chronic liver allograft dysfunction in rats.METHODS:Allogeneic liver transplantation from DA rats to Lewis rats was performed.Chronic liver allograft dysfunction was induced in the rats by administering low-dose tacrolimus at postoperative day (POD) 5.Hepatic overexpression of A20 was achieved by recombinant adenovirus (rAd.)-mediated gene transfer administered intravenously every 10 d starting from POD 10.The recipient rats were injected with physiological saline,rAdEasy-A20 (1 × 109 pfu/30 g weight) or rAdEasy (1 × 109 pfu/30 g weight) every 10 d through the tail vein for 3 mo starting from POD 10.Liver tissue samples were harvested on POD 30 and POD 60.RESULTS:Liver-transplanted rats treated with only tacrolimus showed chronic allograft dysfunction with severe hepatic fibrosis.A20 overexpression ameliorated the effects on liver function,attenuated liver allograft fibrosis and prolonged the survival of the recipient rats.Treatment with A20 suppressed hepatic protein production of tumor growth factor (TGF)1,interleukin1 ,caspase-8,CD40,CD40L,intercellular adhesion molecule-1,vascular cell adhesion molecule-1 and E-selectin.A20 treatment suppressed liver cell apoptosis and inhibited nuclear factorB activation of Kupffer cells (KCs),liver sinusoidal endothelial cells (LSECs) and hepatic stellate cells (HSCs),and it subsequently decreased cytokine mRNA expression in KCs and LSECs and reduced the production of TGF1 in HSCs.CONCLUSION:A20 might prevent chronic liver allograft dysfunction by re-establishing functional homeostasis of KCs,LSECs and HSCs.

Zinc finger E-box-binding homeobox 1 mediates aerobic glycolysis via suppression of sirtuin 3 in pancreatic cancer

AIM To uncover the roles of tumor-promoting gene ZEB1 in aerobic glycolysis regulation and shed light on the underlying molecular mechanism.METHODS Endogenous zinc finger E-box binding homeobox-1(ZEB1) was silenced using a lentivirus-mediated method, and the impact of ZEB1 and methyl-CpG binding domain protein 1(MBD1) on aerobic glycolysis was measured using seahorse cellular flux analyzers, reactive oxygen species quantification, and mitochondrial membrane potential measurement. The interaction between ZEB1 and MBD1 was assessed by co-immunoprecipitation and immunofluorescence assays. The impact of ZEB1 and MBD1 interaction on sirtuin 3(SIRT3) expression was confirmed by quantitative polymerase chain reaction, western blotting, and dual-luciferase and chromatinimmunoprecipitation assays.RESULTS ZEB1 was a positive regulator of aerobic glycolysis in pancreatic cancer. ZEB1 transcriptionally silenced expression of SIRT3, a mitochondrial-localized tumor suppressor, through interaction with MBD1. CONCLUSION ZEB1 silenced SIRT3 expression via interaction with MBD1 to promote aerobic glycolysis in pancreatic cancer.

Zinc Finger Protein-activating Transcription Factor Up-regulates Vascular Endothelial Growth Factor-A Expression in Vitro

Objective To construct the zinc finger protein-activating transcription factor (ZFP-ATF) plasmid and evaluate its efficacy in inducing vascular endothelial growth factor (VEGF) expression in EY.HY926 endothelial cells. Methods Firstly, we constructed the ZFP-ATF plasmid, then testified the quantity of VEGF protein in EY.HY926 endothelial cells after transfected with ZFP-ATP plasmid by Western blot, finally, we used the RT-PCR to testify whether the ZFP-ATF can stimulate expression of VEGF splice variants. Results The ZFP-ATF DNA sequences were located the multiclone sites of PVAX1 vector between the site of BamH Ⅰ and Xhol. Western blot result showed VEGF expression in EY.HY926 endothelial cells transfected with ZFP-ATF plasmid was significantly higher than that in cells transfected with VEGF165 (19.95±3.95 vs. 12.15±1.55 μg/μL, P<0.01). RT-PCR result showed VEGF-A mRNA expression level induced by ZFP-ATF was high than that induced by VEGF165. Conclusion ZFP-ATF can up-regulate the VEGF-A expression in comparison with VEGF165, which might have beneficial effects in angiogenesis process.

Zinc finger protein 139 expression in gastric cancer and its clinical significance

AIM:To investigate the expression of zinc finger protein 139(ZNF139)in gastric cancer(GC),and to analyze its clinical significance.METHODS:A total of 108 patients who were diagnosed with GC and underwent surgery between January 2005and March 2007 were enrolled in this study.Gastric tumor specimens and paired tumor-adjacent tissues were collected and paraffin-embedded,and the clinicopathologic characteristics and prognosis were recorded.The expression of ZNF139,Bcl-2,Bax,and caspase-3 were determined by immunohistochemistry,and apoptosis was assessed by terminal deoxynucleotidyl transferasemediated d UTP-biotin nick end labeling.SPSS 13.0software was used for data processing and analyses,and significance was determined at P<0.05.RESULTS:The expression of ZNF139 was stronger in tumors than in tumor-adjacent tissues(66.67%vs 44.44%;P<0.01).Overexpression of ZNF139correlated with tumor differentiation,invasion depth,clinical stage,lymphatic metastasis,and blood vessel invasion(all P s<0.05).Patients with overexpression of ZNF139 had a poorer prognosis(P<0.01),and overexpression of ZNF139 was an independent factor for the prognosis of GC patients by a Cox survival analysis(P=0.02).A negative relationship between ZNF139 and the apoptosis index was observed(r=-0.686;P<0.01).The expression of Bcl-2 in GC was stronger than in tumor-adjacent tissues(66.67%vs41.67%),whereas the expression levels of Bax and caspase-3 were lower in primary tumors(54.63%and47.22%,respectively)than in tumor-adjacent tissues(73.15%and 73.15%,respectively)(all Ps<0.05).The expression of ZNF139 negatively correlated with caspase-3(r=-0.370;P<0.01).The expressions of Bcl-2 and Bax were also negatively correlated(r=-0.231;P=0.02).The expressions of caspase-3 and Bax protein were positively correlated(r=0.217;P=0.024).CONCLUSION:ZNF139 is related to clinicopathologic characteristics and prognosis of GC.Furthermore,it is overexpressed and involved in apoptosis in GC tissues by regulating caspase-3.

Zinc finger structure-function in Ikaros

The zinc finger motif was used as a vehicle for the initial discovery of Ikaros in the context of T-cell differentiation and has been central to all subsequent analyses of Ikaros function.The Ikaros gene is alternately spliced to produce several isoforms that confer diversity of function and consequently have complicated analysis of the function of Ikaros in vivo.Key features of Ikaros in vivo function are associated with six C2H2 zinc fingers;four of which are alternately incorporated in the production of the various Ikaros isoforms.Although no complete structures are available for the Ikaros protein or any of its family members,considerable evidence has accumulated about the structure of zinc fingers and the role that this structure plays in the functions of the Ikaros family of proteins.This review summarizes the structural aspects of Ikaros zinc fingers,individually,and in tandem to provide a structural context for Ikaros function and to provide a structural basis to inform the design of future experiments with Ikaros and its family members.

In Vivo Modeling of Zebrafish Zinc Finger,MIZ-Type Containing 1 Expression and Its Effect on Pigmentation

Objective:The zinc finger,MIZ-type containing 1(ZMIZ1)gene has been identified as a possible susceptibility gene associated with vitiligo,therefore we conducted this study to investigate the role ofZMIZ1 in pigmentation.Methods:We generate a zebrafish loss-of-function model using morpholino oligonucleotides(MOs),and two orthologs of humanZMIZ1 have been annotated(ZMIZ1a andZMIZ1b).The expression profiles of ZMIZ1a and ZMIZ1b and their effects on the pigmentation in zebrafish were evaluated by using whole-mount in situ hybridization and melanin quantification.Statistical analysis was performed using the unpaired Studentt-test or one-way analysis.Results:Investigation of the temporal and spatial expressions of these two transcripts suggested that the expressions ofZMIZ1a andZMIZ1b in the brain start to emerge in a ubiquitous fashion from 2 days post-fertilization onwards.After the successful design and validation of MOs,we observed thatZMIZ1a andZMIZ1b MOs caused embryonic developmental delays and malformations in zebrafish.Further analysis of the melanin content in the morphants revealed thatZMIZ1a significantly(49.1%for 0.667 mmol/L inZMIZI1a group,P=0.03)reduced the melanin content in a dose-dependent manner,but only the highest concentration of injectedZMIZ1b MOs significantly(50%for 0.667 mmol/L inZMIZ1b group,P=0.02)reduced the melanin content.A tyrosinase inhibition assay indicated no significant difference between the morphants and wild-type zebrafish.Conclusion:This study successfully modeled a susceptibility gene identified by genome-wide association studies in a zebrafish loss-of-function model and provides insights into the biological mechanism of pigmentation.

Phylogenetic Analysis of the Plant-specific Zinc Finger-Homeobox and Mini Zinc Finger Gene Families

Zinc finger-homeodomain proteins （ZHD） are present in many plants; however, the evolutionary history of the ZHD gene family remains largely unknown. We show here that ZHD genes are plant-specific, nearly all intronless, and related to MINI ZINC FINGER （MIF） genes that possess only the zinc finger. Phylogenetic analyses of ZHD genes from representative land plants suggest that non.seed plant ZHD genes occupy basal positions and angiosperm homologs form seven distinct clades. Several clades contain genes from two or more major angiosperm groups, including eudicots, monocots, magnoliids, and other basal angiosperms, indicating that several duplications occurred before the diversification of flowering plants. In addition, specific lineages have experienced more recent duplications. Unlike the ZHD genes, MIFs are found only from seed plants, possibly derived from ZHDs by loss of the homeodomain before the divergence of seed plants. Moreover, the MIF genes have also undergone relatively recent gene duplications. Finally, genome duplication might have contributed substantially to the expansion of family size in angiosperms and caused a high level of functional redundancy/overlap in these genes.

The C_2H_2 -type Zinc Finger Protein ZFP182 is Involved in Abscisic Acid-Induced Antioxidant Defense in Rice

C2H2-type zinc finger proteins （ZFPs） are thought to play important roles in modulating the responses of plants to drought, salinity and oxidative stress. However, direct evidence is lacking for the involvement of these ZFPs in abscisic acid （ABA）-induced antioxidant defense in plants. In this study, the role of the rice （Oryza sativa L. sub.japonica cv. Nipponbare） C2H2-type ZFP ZFP182 in ABA-induced antioxidant defense and the relationship between ZFP182 and two rice MAPKs, OsMPK1 and OsMPK5 in ABA signaling were investigated. ABA treatment induced the increases in the expression of ZFP182, OsMPK1 and OsMPK5, and the activities of superoxide dismutase （SOD） and ascorbate peroxidase （APX） in rice leaves. The transient gene expression analysis and the transient RNA interference （RNAi） analysis in protoplasts showed that ZFP182, OsMPK1 and OsMPK5 are involved in ABA-induced up-regulation in the activities of SOD and APX. Besides, OsMPK1 and OsMPK5 were shown to be required for the up-regulation in the expression of ZFP182 in ABA signaling, but ZFP182 did not mediate the ABA-induced up-regulation in the expression of OsMPK1 and OsMPKS. These results indicate that ZFP182 is required for ABA-induced antioxidant defense and the expression of ZFP182 is regulated by rice MAPKs in ABA signaling.

A zinc finger protein, interacted with cyclophilin,affects root development via IAA pathway in rice

The plant hormone auxin plays a crucial role in lateral root development. To better understand the rnolecular mechanisms underlying lateral root formation, an auxin-responsive gene OsCYP2 （Oso2g0121300） was characterized from rice. Compared to the wild type, OsCYP2-RNAi （RNA interference） lines exhibited distinctive defects in lateral root development. Yeast two-hybrid and glutathione S-transferase puIl-down results confirmed that OsCYP2 interacted with a C2HC-type zinc finger protein （OsZFP, O501g0252900） which is located in the rice nucleus. T2OsZFP-RNAi lines had significantly fewer lateral roots than did wild-type plants, which suggests a role for OsCYP2 and OsZFP in regulating lateral root development.Quantitative real-time polymerase chain reaction showed that the expression of certain Aux/IAA （auxin/indole-3- acetic acid） genes was altered in OsCYP2- and OsZFP-RNAi lines in response to IAA. These findings imply that OsCYP2 and OsZFP participate in IAA signal pathways controlling lateral root development. More importantly, OslAA11 showed functional redundancy not only in OsCYP2-RNAi lines but also in OsZFP-RNAi lines, which provides important clues for the elucidation of mechanisms controlling lateral root development in response to auxin.

Involvement of C2H2 zinc finger proteins in the regulation of epidermal cell fate determination in Arabidopsis

Cell fate determination is a basic developmental process during the growth of multicellular organisms.Trichomes and root hairs of Arabidopsis are both readily accessible structures originating from the epidermal cells of the aerial tissues and roots respectively, and they serve as excellent models for understanding the molecular mechanisms controlling cell fate determination and cell morphogenesis. The regulation of trichome and root hair formationis a complex program that consists of the integration of hormonal signals with a large number of transcriptional factors, including MYB and b HLH transcriptional factors.Studies during recent years have uncovered an important role of C2H2 type zinc finger proteins in the regulation of epidermal cell fate determination. Here in this minireview we briefly summarize the involvement of C2H2 zinc finger proteins in the control of trichome and root hair formation in Arabidopsis.

Structure and Function of N-Terminal Zinc Finger Domain of SARS-CoV-2 NSP2

SARS-CoV-2 has become a global pandemic threatening human health and safety.It is urgent to find effective therapeutic agents and targets with the continuous emergence of novel mutant strains.The knowledge of the molecular basis and pathogenesis of SARS-CoV-2 in host cells requires to be understood comprehensively.The unknown structure and function of nsp2 have hindered our understanding of its role in SARS-CoV-2 infection.Here,we report the crystal structure of the N-terminal of SARS-CoV-2 nsp2 to a high resolution of 1.96?.This novel structure contains three zinc fingers,belonging to the C2 H2,C4,and C2 HC types,respectively.Structure analysis suggests that nsp2 may be involved in binding nucleic acids and regulating intracellular signaling pathways.The binding to single or double-stranded nucleic acids was mainly through the large positively charged region on the surface of nsp2,and K111,K112,K113 were key residues.Our findings lay the foundation for a better understanding of the relationship between structure and function for nsp2.It is helpful to make full use of nsp2 as further research and development of antiviral targets and drug design.

OsIDD2, a zinc finger and INDETERMINATE DOMAIN protein, regulates secondary cell wall formation

Previously, we found 123 transcription factors（TFs） as candidate regulators of secondary cell wall（SCW）formation in rice by using phylogenetic and co-expression network analyses. Among them, we examined in this work the role of OsIDD_2, a zinc finger and indeterminate domain（IDD） family TF. Its overexpressors showed dwarfism, fragile leaves, and decreased lignin content, which are typical phenotypes of plants defective in SCW formation, whereas its knockout plants showed slightly increased lignin content.The RNA-seq and quantitative reverse transcription polymerase chain reaction analyses confirmed that some lignin biosynthetic genes were downregulated in the OsIDD_2-overexpressing plants, and revealed the same case for other genes involved in cellulose synthesis and sucrose metabolism. The transient expression assay using rice protoplasts revealed that OsIDD_2 negatively regulates the transcription of genes involved in lignin biosynthesis, cinnamyl alcohol dehydrogenase 2 and 3（CAD_2 and 3）, and sucrose metabolism, sucrose synthase 5（SUS_5）, whereas an Alpha Screen assay, which can detect the interaction between TFs and their target DNA sequences, directly confirmed the interaction between OsIDD_2 and the target sequences located in the promoter regions of CAD_2 and CAD_3. Based on these observations, we conclude that OsIDD_2 is negatively involved in SCW formation and other biological events by downregulating its target genes.

Fruit size control by a zinc finger protein regulating pericarp cell size in tomato

Fruit size is largely defined by the number and size of cells in the fruit.Endoreduplication–a specialized cell cycle–is highly associated with cell expansion during tomato fruit growth.However,how endoreduplication coupled with cell size is regulated remains poorly understood.In this study,we identified a zinc finger gene SlPZF1(Solanum lycopersicum PERICARP-ASSOCIATED ZINC FINGER PROTEIN 1)that was highly expressed in the pericarp of developing fruits.Plants with altered SlPZF1 expression produced smaller fruits due to the reduction in cell size associated with weakened endoreduplication.Overexpressing SlPZF1 delayed cell division phase by enhancing early expression of several key cell cycle regulators including SlCYCD3;1 and two plant specific mitotic cyclin-dependent protein kinase(SlCDKB1 and SlCDKB2)in the pericarp tissue.Furthermore,we identified 14 putative SlPZF1 interacting proteins(PZFIs)via yeast two hybrid screening.Several PZFIs,including Pre-mRNA-splicing factor(SlSMP1/PZFI4),PAPA-1-like conserved region family protein(PZFI6),Fanconi anemia complex components(PZFI3 and PZFI10)and bHLH transcription factor LONESOME HIGHWAY(SILHW/PZFI14),are putatively involved in cell cycle regulation.Our results demonstrate that fruit growth in tomato requires balanced expression of the novel cell size regulator SlPZF1.