In vivo transgenic studies confirm the critical acylation function of LeBAHD56 for shikonin in Lithospermum erythrorhizon.

KEY MESSAGE: LeBAHD56 is preferentially expressed in tissues where shikonin and its derivatives are biosynthesized, and it confers shikonin acylation in vivo. Two WRKY transcriptional factors might regulate LeBAHD56's expression. Shikonin and its derivatives, found in the roots of Lithospermum erythrorhizon, have extensive application in the field of medicine, cosmetics, and other industries. Prior research has demonstrated that LeBAHD1(LeSAT1) is responsible for the biochemical process of shikonin acylation both in vitro and in vivo. However, with the exception of its documented in vitro biochemical function, there is no in vivo genetic evidence supporting the acylation function of the highly homologous gene of LeSAT1, LeBAHD56(LeSAT2), apart from its reported role. Here, we validated the critical acylation function of LeBAHD56 for shikonin using overexpression (OE) and CRISPR/Cas9-based knockout (KO) strategies. The results showed that the OE lines had a significantly higher ratio of acetylshikonin, isobutyrylshikonin or isovalerylshikonin to shikonin than the control. In contrast, the KO lines had a significantly lower ratio of acetylshikonin, isobutyrylshikonin or isovalerylshikonin to shikonin than controls. As for its detailed expression patterns, we found that LeBAHD56 is preferentially expressed in roots and callus cells, which are the biosynthesis sites for shikonin and its derivatives. In addition, we anticipated that a wide range of putative transcription factors might control its transcription and verified the direct binding of two crucial WRKY members to the LeBAHD56 promoter's W-box. Our results not only confirmed the in vivo function of LeBAHD56 in shikonin acylation, but also shed light on its transcriptional regulation.

[Primary mucinous gland lesions of fallopian tube: a clinicopathological analysis of fourteen cases].

Objective: To investigate the clinical and pathological characteristics of primary mucinous gland lesions of the fallopian tubes. Methods: The clinical data, pathomorphological characteristics and immunophenotype of 14 cases of primary mucinous gland lesions of the fallopian tube diagnosed at Obstetrics and Gynecology Hospital of Fudan University from 2015 to 2023 were analyzed retrospectively. In addition, a comprehensive review of relevant literature was conducted. Results: The age of 14 patients ranged from 53 to 83 years, with an average of 65 years. Among them, 13 cases exhibited unilateral involvement while one case showed bilateral presentation. Nine cases were mucinous metaplasia of the fallopian tube, four cases were invasive mucinous adenocarcinoma and one case was mucinous carcinoma in situ. Morphologically, mucinous metaplasia of the fallopian tube was focal, with or without inflammation. The cells of mucinous adenocarcinoma or mucinous carcinoma in situ exhibited characteristics indicative of gastrointestinal differentiation. Immunohistochemical analysis revealed diffuse positive expression of CK7, and negative expression of SATB2. CDX2 demonstrated positive staining in two cases. One case exhibited diffuse and strongly positive mutant expression of p53, whereas the remaining cases displayed wild-type expression. MUC6 showed diffuse or focally positive staining in mucinous gland lesions characterized by gastric differentiation. Some cases of mucinous adenocarcinoma of fallopian tube were subject to AB-PAS staining, resulting in red to purple cytoplasmic staining. Conclusions: Primary mucinous lesions of the fallopian tube are exceedingly uncommon. All cases of mucinous adenocarcinoma of fallopian tubes in this study exhibit the morphology and immunohistochemical characteristics of gastrointestinal differentiation. Mucinous metaplasia of the fallopian tube is a benign lesion of incidental finding, which is closely related to inflammation or gastric differentiation. Mucinous lesions of cervix, ovary and digestive tract are excluded in all patients, confirming the independent existence of mucinous lesions within fallopian tubes.

Disparity of gene expression in coronary artery disease: insights from MEIS1, HIRA, and Myocardin.

INTRODUCTION: Coronary artery disease (CAD) in young adults can have devastating consequences. The cardiac developmental gene MEIS1 plays important roles in vascular networks and heart development. This gene effects on the regeneration capacity of the heart. Considering role of MEIS1 in cardiac tissue development and the progression of myocardial infarction this study investigated the expression levels of the MEIS1, HIRA, and Myocardin genes in premature CAD patients compared to healthy subjects and evaluated the relationships between these genes and possible inflammatory factors. METHODS AND RESULTS: The study conducted a case-control design involving 35 CAD patients and 35 healthy individuals. Peripheral blood mononuclear cells (PBMCs) were collected, and gene expression analysis was performed using real-time PCR. Compared with control group, the number of PBMCs in the CAD group exhibited greater MEIS1 and HIRA gene expression, with fold changes of 2.45 and 3.6. The expression of MEIS1 exhibited a negative correlation with IL-10 (r= -0.312) expression and positive correlation with Interleukin (IL)-6 (r = 0.415) and tumor necrosis factor (TNF)-α (r = 0.534) gene expression. Moreover, there was an inverse correlation between the gene expression of HIRA and that of IL-10 (r= -0.326), and a positive correlation was revealed between the expression of this gene and that of the IL-6 (r = 0.453) and TNF-α (r = 0.572) genes. CONCLUSION: This research demonstrated a disparity in expression levels of MEIS1, HIRA, and Myocardin, between CAD and healthy subjects. The results showed that, MEIS1 and HIRA play significant roles in regulating the synthesis of proinflammatory cytokines, namely, TNF-α and IL-6.

Prognostic significance of CHCHD2P9 and ZNF204P in breast cancer: exploring their expression patterns and associations with malignancy-related genes.

BACKGROUND: Non-coding RNAs (ncRNAs) have a crucial impact on diverse cellular processes, influencing the progression of breast cancer (BC). The objective of this study was to identify novel ncRNAs in BC with potential effects on patient survival and disease progression. METHODS: We utilized the cancer genome atlas data to identify ncRNAs associated with BC pathogenesis. We explored the association between these ncRNA expressions and survival rates. A risk model was developed using candidate ncRNA expression and beta coefficients obtained from a multivariate Cox regression analysis. Co-expression networks were constructed to determine potential relationships between these ncRNAs and molecular pathways. For validation, we employed BC samples and the RT-qPCR method. RESULTS: Our findings revealed a noteworthy increase in the expression of AC093850.2 and CHCHD2P9 in BC, which was correlated with a poor prognosis. In contrast, ADAMTS9-AS1 and ZNF204P displayed significant downregulation and were associated with a favorable prognosis. The risk model, incorporating these four ncRNAs, robustly predicted patient survival. The co-expression network showed an effective association between levels of AC093850.2, CHCHD2P9, ADAMTS9-AS1, and ZNF204P and genes involved in pathways like metastasis, angiogenesis, metabolism, and DNA repair. The RT-qPCR results verified notable alterations in the expression of CHCHD2P9 and ZNF204P in BC samples. Pan-cancer analyses revealed alterations in the expression of these two ncRNAs across various cancer types. CONCLUSION: This study presents a groundbreaking discovery, highlighting the substantial dysregulation of CHCHD2P9 and ZNF204P in BC and other cancers, with implications for patient survival.

The transcription factor WRKY22 modulates ethylene biosynthesis and root development through transactivating the transcription of ACS5 and ACO5 in Arabidopsis.

The WRKY transcription factor (TF) genes form a large family in higher plants, with 72 members in Arabidopsis (Arabidopsis thaliana). The gaseous phytohormone ethylene (ET) regulates multiple physiological processes in plants. It is known that 1-aminocyclopropane-1-carboxylic acid (ACC) synthases (ACSs, EC 4.4.1.14) limit the enzymatic reaction rate of ethylene synthesis. However, whether WRKY TFs regulate the expression of ACSs and/or ACC oxidases (ACOs, EC 1.14.17.4) remains largely elusive. Here, we demonstrated that Arabidopsis WRKY22 positively regulated the expression of a few ACS and ACO genes, thus promoting ethylene production. Inducible overexpression of WRKY22 caused shorter hypocotyls without ACC treatment. A qRT-PCR screening demonstrated that overexpression of WRKY22 activates the expression of several ACS and ACO genes. The promoter regions of ACS5, ACS11, and ACO5 were also activated by WRKY22, which was revealed by a dual luciferase reporter assay. A follow-up chromatin immunoprecipitation coupled with quantitative PCR (ChIP-qPCR) and electrophoretic mobility shift assay (EMSA) showed that the promoter regions of ACS5 and ACO5 could be bound by WRKY22 directly. Moreover, wrky22 mutants had longer primary roots and more lateral roots than wild type, while WRKY22-overexpressing lines showed the opposite phenotype. In conclusion, this study revealed that WRKY22 acts as a novel TF activating, at least, the expression of ACS5 and ACO5 to increase ethylene synthesis and modulate root development.

Muscle-specific pyruvate kinase isoforms, PKM1 and PKM2, regulate mammalian SWI/SNF proteins and histone 3 phosphorylation during myoblast differentiation.

Pyruvate kinase is a glycolytic enzyme that converts phosphoenolpyruvate and ADP into pyruvate and ATP. There are two genes that encode pyruvate kinase in vertebrates; Pkm and Pkl encode muscle- and liver/erythrocyte-specific forms, respectively. Each gene encodes two isoenzymes due to alternative splicing. Both muscle-specific enzymes, PKM1 and PKM2, function in glycolysis, but PKM2 also has been implicated in gene regulation due to its ability to phosphorylate histone 3 threonine 11 (H3T11) in cancer cells. Here, we examined the roles of PKM1 and PKM2 during myoblast differentiation. RNA-seq analysis revealed that PKM2 promotes the expression of Dpf2/Baf45d and Baf250a/Arid1A. DPF2 and BAF250a are subunits that identify a specific sub-family of the mammalian SWI/SNF (mSWI/SNF) of chromatin remodeling enzymes that is required for the activation of myogenic gene expression during differentiation. PKM2 also mediated the incorporation of DPF2 and BAF250a into the regulatory sequences controlling myogenic gene expression. PKM1 did not affect expression but was required for nuclear localization of DPF2. Additionally, PKM2 was required not only for the incorporation of phosphorylated H3T11 in myogenic promoters but also for the incorporation of phosphorylated H3T6 and H3T45 at myogenic promoters via regulation of AKT and protein kinase C isoforms that phosphorylate those amino acids. Our results identify multiple unique roles for PKM2 and a novel function for PKM1 in gene expression and chromatin regulation during myoblast differentiation.

Structural insights into the regulation mechanism of Mycobacterium tuberculosis MftR.

Mycobacterium tuberculosis, the pathogen of the deadly disease tuberculosis, depends on the redox cofactor mycofactocin (MFT) to adapt to and survive under hypoxic conditions. MftR is a TetR family transcription regulator that binds upstream of the MFT gene cluster and controls MFT synthesis. To elucidate the structural basis underlying MftR regulation, we determined the crystal structure of Mycobacterium tuberculosis MftR (TB-MftR). The structure revealed an interconnected hydrogen bond network in the α1-α2-α3 helices of helix-turn-helix (HTH) DNA-binding domain that is essential for nucleic acid interactions. The ligand-binding domain contains a hydrophobic cavity enclosing long-chain fatty acyl-CoAs like the key regulatory ligand oleoyl-CoA. Despite variations in ligand-binding modes, comparative analyses suggest regulatory mechanisms are largely conserved across TetR family acyl-CoA sensors. By elucidating the intricate structural mechanisms governing DNA and ligand binding by TB-MftR, our study enhances understanding of the regulatory roles of this transcription factor under hypoxic conditions, providing insights that could inform future research into Mycobacterium tuberculosis pathogenesis.

A PRMT5-ZNF326 axis mediates innate immune activation upon replication stress.

DNA replication stress (RS) is a widespread phenomenon in carcinogenesis, causing genomic instability and extensive chromatin alterations. DNA damage leads to activation of innate immune signaling, but little is known about transcriptional regulators mediating such signaling upon RS. Using a chemical screen, we identified protein arginine methyltransferase 5 (PRMT5) as a key mediator of RS-dependent induction of interferon-stimulated genes (ISGs). This response is also associated with reactivation of endogenous retroviruses (ERVs). Using quantitative mass spectrometry, we identify proteins with PRMT5-dependent symmetric dimethylarginine (SDMA) modification induced upon RS. Among these, we show that PRMT5 targets and modulates the activity of ZNF326, a zinc finger protein essential for ISG response. Our data demonstrate a role for PRMT5-mediated SDMA in the context of RS-induced transcriptional induction, affecting physiological homeostasis and cancer therapy.

The browning and mobilization of subcutaneous white adipose tissue supports efficient skin repair.

Adipocytes in dermis are considered to be important participants in skin repair and regeneration, but the role of subcutaneous white adipose tissue (sWAT) in skin repair is poorly understood. Here, we revealed the dynamic changes of sWAT during wound healing process. Lineage-tracing mouse studies revealed that sWAT would enter into the large wound bed and participate in the formation of granulation tissue. Moreover, sWAT undergoes beiging after skin injury. Inhibition of sWAT beiging by genetically silencing PRDM16, a key regulator to beiging, hindered wound healing process. The transcriptomics results suggested that beige adipocytes in sWAT abundantly express neuregulin 4 (NRG4), which regulated macrophage polarization and the function of myofibroblasts. In diabetic wounds, the beiging of sWAT was significantly suppressed. Thus, adipocytes from sWAT regulate multiple aspects of repair and may be therapeutic for inflammatory diseases and defective wound healing associated with aging and diabetes.

[Mechanism of miR-221-3p inhibiting cadmium-induced apoptosis of TM3 cells through DDIT4].

OBJECTIVE: To investigate the mechanism of DNA-damage-inducible transcript 4(DDIT4)targeting miR-221-3p in microRNA(miRNA) on cadmium-induced apoptosis of mouse testicular stromal cells. METHODS: The activity of mouse testicular interstitial cells(TM3) was detected by CCK-8 after exposure to different concentrations of cadmium(0, 10, 20, 30, 40 µmol/L). Total RNA was extracted from cadmium-treated TM3 cells, and the significantly differentially expressed miRNA was screened with fold change(FC)>1.2 and P<0.05 as the criterion. TM3 cells were divided into blank control group, negative control group, cadmium exposure group(CdCl_2, 20 µmol/L), and cadmium+miR-221-3p mimic group. miR-221-3p mimic group was transfected into TM3 cells first, combined with cadmium exposure for 24 hours. The cell morphology was detected by Hoechst staining, and the apoptosis rate was analyzed by flow cytometry. Quantitative real-time PCR(qRT-PCR) and Western blot were used to detect DDIT4 expression. Dual luciferase reporter gene assay verified the binding of miR-221-3p to DDIT4. The function of DDIT4 and its relationship with apoptosis were analyzed by bioinformatics. The expression levels of B-cell lymphoma-2(Bcl-2) and Bcl-2 associated X protein(BAX) were observed after overexpression of miR-221-3p. RESULTS: Cadmium treatment of TM3 cells could reduce cell activity and there was a dose-effect relationship. The cell morphology showed that compared with the control group, the cells were wrinkled and the nuclei were heavily stained, and the apoptosis rate increased to 19.66%±0.45%(P<0.01). Compared with the cadmium exposure group, the normal morphologic cells increased in the cadmium exposure +miR-221-3p mimic group, and the apoptosis rate decreased to 13.76%±0.37%(P<0.05). The expression level of miR-221-3p was down-regulated(P<0.01), and the expression level of DDIT4 was up-regulated(P<0.05). Bioinformatics analysis and dual luciferase report analysis showed that DDIT4 was one of the target genes of miR-221-3p. Compared with the cadmium exposure group, the expression level of DDIT4 in the cadmium+miR-221-3p mimic group was down-regulated(P<0.05), and the ratio of Bcl-2/BAX was increased from 0.54±0.03 to 0.71±0.04. CONCLUSION: miR-221-3p inhibits cadmium-induced apoptosis of TM3 cells by targeting DDIT4.

Cereal genetics: Novel modulators of spikelet number and flowering time.

The spikelet is the unit component of the spike and the site of grain production in Triticeae crops. Two new studies revealed that plant-specific transcription factors ALOG1 and PDB1 participate in modulating spikelet number and flowering time in barley and wheat.

A History of Cancer Research: Oncogenic Transcription Factors.

Transcription factors play crucial roles in cancer, and oncogenic counterparts of cellular transcription factors are present in a number of tumor viruses. It was studies in the early 1980s that first showed tumor viruses could encode nuclear as well as cytoplasmic oncoproteins. Subsequent work provided detailed insight into their mechanisms of action, as well as potential therapeutic avenues. In this excerpt from his forthcoming book on the history of cancer research, Joe Lipsick looks back at early work on nuclear oncogenes, including the discovery of MYC, MYB, FOS and JUN, Rel/NF-κB, and nuclear receptors such as the retinoic acid receptor and thyroid hormone receptor.

Integrated analysis of the role of PR/SET domain 14 in gastric cancer.

BACKGROUND: Gastric cancer is one of the most common tumors worldwide, and most patients are deprived of treatment options when diagnosed at advanced stages. PRDM14 has carcinogenic potential in breast and non-small cell lung cancer. however, its role in gastric cancer has not been elucidated. METHODS: We aimed to elucidate the expression of PRDM14 using pan-cancer analysis. We monitored the expression of PRDM14 in cells and patients using quantitative polymerase chain reaction, western blotting, and immunohistochemistry. We observed that cell phenotypes and regulatory genes were influenced by PRDM14 by silencing PRDM14. We evaluated and validated the value of the PRDM14-derived prognostic model. Finally, we predicted the relationship between PRDM14 and small-molecule drug responses using the Connectivity Map and The Genomics of Drug Sensitivity in Cancer databases. RESULTS: PRDM14 was significantly overexpressed in gastric cancer, which identified in cell lines and patients' tissues. Silencing the expression of PRDM14 resulted in apoptosis promotion, cell cycle arrest, and inhibition of the growth and migration of GC cells. Functional analysis revealed that PRDM14 acts in epigenetic regulation and modulates multiple DNA methyltransferases or transcription factors. The PRDM14-derived differentially expressed gene prognostic model was validated to reliably predict the patient prognosis. Nomograms (age, sex, and PRDM14-risk score) were used to quantify the probability of survival. PRDM14 was positively correlated with sensitivity to small-molecule drugs such as TPCA-1, PF-56,227, mirin, and linsitinib. CONCLUSIONS: Collectively, our findings suggest that PRDM14 is a positive regulator of gastric cancer progression. Therefore, it may be a potential therapeutic target for gastric cancer.

Imprinted DNA methylation of the H19 ICR is established and maintained in vivo in the absence of Kaiso.

BACKGROUND: Paternal allele-specific DNA methylation of the imprinting control region (H19 ICR) controls genomic imprinting at the Igf2/H19 locus. We previously demonstrated that the mouse H19 ICR transgene acquires imprinted DNA methylation in preimplantation mouse embryos. This activity is also present in the endogenous H19 ICR and protects it from genome-wide reprogramming after fertilization. We also identified a 118-bp sequence within the H19 ICR that is responsible for post-fertilization imprinted methylation. Two mutations, one in the five RCTG motifs and the other a 36-bp deletion both in the 118-bp segment, caused complete and partial loss, respectively, of methylation following paternal transmission in each transgenic mouse. Interestingly, these mutations overlap with the binding site for the transcription factor Kaiso, which is reportedly involved in maintaining paternal methylation at the human H19 ICR (IC1) in cultured cells. In this study, we investigated if Kaiso regulates imprinted DNA methylation of the H19 ICR in vivo. RESULTS: Neither Kaiso deletion nor mutation of Kaiso binding sites in the 118-bp region affected DNA methylation of the mouse H19 ICR transgene. The endogenous mouse H19 ICR was methylated in a wild-type manner in Kaiso-null mutant mice. Additionally, the human IC1 transgene acquired imprinted DNA methylation after fertilization in the absence of Kaiso. CONCLUSIONS: Our results indicate that Kaiso is not essential for either post-fertilization imprinted DNA methylation of the transgenic H19 ICR in mouse or for methylation imprinting of the endogenous mouse H19 ICR.

ATP-dependent chromatin remodeller brahma related gene 1 promotes keratinocyte migration and modulates cell Signalling during wound healing in human skin.

Skin wound healing is driven by proliferation, migration and differentiation of several cell types that are controlled by the alterations in the gene expression programmes. Brahma Gene 1 (BRG1) (also known as SMARCA4) is a core ATPase in the BRG1 Associated Factors (BAF) ATP-dependent chromatin remodelling complexes that alter DNA-histone interaction in chromatin at the specific gene regulatory elements resulting in increase or decrease of the target gene transcription. Using siRNA mediated suppression of BRG1 during wound healing in a human ex vivo and in vitro (scratch assay) models, we demonstrated that BRG1 is essential for efficient skin wound healing by promoting epidermal keratinocytes migration, but not their proliferation or survival. BRG1 controls changes in the expression of genes associated with gene transcription, response to wounding, cell migration and cell signalling. Altogether, our data revealed that BRG1 play positive role in skin repair by promoting keratinocyte migration and impacting the genes expression programmes associated with cell migration and cellular signalling.

Vernalization promotes bolting in sugar beet by inhibiting the transcriptional repressors of BvGI.

Sugar beet (Beta vulgaris L.), a biennial sugar crop, contributes about 16% of the world's sugar production. The transition from vegetative growth, during which sugar accumulated in beet, to reproductive growth, during which sugar exhausted in beet, is determined by vernalization and photoperiod. GIGANTEA (GI) is a key photoperiodic flowering gene that is induced by vernalization in sugar beet. To identify the upstream regulatory factors of BvGI, candidate transcription factors (TF) that were co-expressed with BvGI and could bind to the BvGI promoter were screened based on weighted gene co-expression network analysis (WGCNA) and TF binding site prediction. Subsequently, their transcriptional regulatory role on the BvGI was validated through subcellular localization, dual-luciferase assays and yeast transformation tests. A total of 7,586 differentially expressed genes were identified after vernalization and divided into 18 co-expression modules by WGCNA, of which one (MEcyan) and two (MEdarkorange2 and MEmidnightblue) modules were positively and negatively correlated with the expression of BvGI, respectively. TF binding site predictions using PlantTFDB enabled the screening of BvLHY, BvTCP4 and BvCRF4 as candidate TFs that negatively regulated the expression of BvGI by affecting its transcription. Subcellular localization showed that BvLHY, BvTCP4 and BvCRF4 were localized to the nucleus. The results of dual-luciferase assays and yeast transformation tests showed that the relative luciferase activity and expression of HIS3 was reduced in the BvLHY, BvTCP4 and BvCRF4 transformants, which suggested that the three TFs inhibited the BvGI promoter. In addition, real-time quantitative reverse transcription PCR showed that BvLHY and BvTCP4 exhibited rhythmic expression characteristics similar to that of BvGI, while BvCRF4 did not. Our results revealed that vernalization crosstalked with the photoperiod pathway to initiate bolting in sugar beet by inhibiting the transcriptional repressors of BvGI.

ETV5 promotes lupus pathogenesis and follicular helper T cell differentiation by inducing osteopontin expression.

Follicular helper T (TFH) cells mediate germinal center reactions to generate high affinity antibodies against specific pathogens, and their excessive production is associated with the pathogenesis of systemic autoimmune diseases such as systemic lupus erythematosus (SLE). ETV5, a member of the ETS transcription factor family, promotes TFH cell differentiation in mice. In this study, we examined the role of ETV5 in the pathogenesis of lupus in mice and humans. T cell-specific deletion of Etv5 alleles ameliorated TFH cell differentiation and autoimmune phenotypes in lupus mouse models. Further, we identified SPP1 as an ETV5 target that promotes TFH cell differentiation in both mice and humans. Notably, extracellular osteopontin (OPN) encoded by SPP1 enhances TFH cell differentiation by activating the CD44-AKT signaling pathway. Furthermore, ETV5 and SPP1 levels were increased in CD4+ T cells from patients with SLE and were positively correlated with disease activity. Taken together, our findings demonstrate that ETV5 is a lupus-promoting transcription factor, and secreted OPN promotes TFH cell differentiation.

Role of Mod(mdg4)-67.2 Protein in Interactions between Su(Hw)-Dependent Complexes and Their Recruitment to Chromatin.

Su(Hw) belongs to the class of proteins that organize chromosome architecture, determine promoter activity, and participate in formation of the boundaries/insulators between the regulatory domains. This protein contains a cluster of 12 zinc fingers of the C2H2 type, some of which are responsible for binding to the consensus site. The Su(Hw) protein forms complex with the Mod(mdg4)-67.2 and the CP190 proteins, where the last one binds to all known Drosophila insulators. To further study functioning of the Su(Hw)-dependent complexes, we used the previously described su(Hw)E8 mutation with inactive seventh zinc finger, which produces mutant protein that cannot bind to the consensus site. The present work shows that the Su(Hw)E8 protein continues to directly interact with the CP190 and Mod(mdg4)-67.2 proteins. Through interaction with Mod(mdg4)-67.2, the Su(Hw)E8 protein can be recruited into the Su(Hw)-dependent complexes formed on chromatin and enhance their insulator activity. Our results demonstrate that the Su(Hw) dependent complexes without bound DNA can be recruited to the Su(Hw) binding sites through the specific protein-protein interactions that are stabilized by Mod(mdg4)-67.2.