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Jing Wang, Fengchun Zhang and colleagues report the results of a genome-wide association study of primary Sjögren's syndrome, a common autoimmune disease. They confirm associations in the STAT4 , TNFAIP3 and HLA regions and identify a new susceptibility locus in the GTF2I region at 7q11.23. Primary Sjögren's syndrome is one of the most common autoimmune diseases. So far, genetic studies of Sjögren's syndrome have relied mostly on candidate gene approaches. To identify new genetic susceptibility loci for primary Sjögren's syndrome, we performed a three-stage genome-wide association study in Han Chinese. In the discovery stage, we analyzed 556,134 autosomal SNPs in 542 cases and 1,050 controls. We then validated promising associations in 2 replication stages comprising 1,303 cases and 2,727 controls. The combined analysis identified GTF2I at 7q11.23 (rs117026326: P combined = 1.31 × 10 −53 , combined odds ratio (OR combined ) = 2.20) as a new susceptibility locus for primary Sjögren's syndrome. Our analysis also confirmed previously reported associations in Europeans in the regions of STAT4 , TNFAIP3 and the major histocompatibility complex (MHC). Fine mapping of the region around GTF2I showed that rs117026326 in GTF2I had the most significant association, with associated SNPs extending from GTF2I to GTF2IRD1 - GTF2I .

In eukaryotes, the general transcription factors TFIIE and TFIIH assemble at the transcription start site with RNA Polymerase II. However, the mechanism by which these transcription factors incorporate the preinitiation complex and coordinate their action during RNA polymerase II transcription remains elusive. Here we show that the TFIIEα and TFIIEβ subunits anchor the TFIIH kinase module (CAK) within the preinitiation complex. In addition, we show that while RNA polymerase II phosphorylation and DNA opening occur, CAK and TFIIEα are released from the promoter. This dissociation is impeded by either ATP-γS or CDK7 inhibitor THZ1, but still occurs when XPB activity is abrogated. Finally, we show that the Core-TFIIH and TFIIEβ are subsequently removed, while elongation factors such as DSIF are recruited. Remarkably, these early transcriptional events are affected by TFIIE and TFIIH mutations associated with the developmental disorder, trichothiodystrophy. The general transcription factors TFIIE and TFIIH assemble at the transcription start site with RNA Polymerase II. Here the authors provide evidence that the TFIIEα and TFIIEβ subunits anchor the TFIIH kinase module within the preinitiation complex before their release during transcription.

The general transcription factors TFIIE and TFIIH subunit Ssl2/XPB function in the transition of the preinitiation complex (PIC) to the open polymerase II (Pol II) complex. Efforts to localize TFIIE and Ssl2 in the yeast PIC now reveal crucial roles for the three TFIIE winged-helix domains and for Ssl2 in promoting DNA strand separation. Yeast RNA polymerase II (Pol II) general transcription factor TFIIE and the TFIIH subunit Ssl2 (yeast ortholog of mammalian XPB) function in the transition of the preinitiation complex (PIC) to the open complex. We show that the three TFIIE winged-helix (WH) domains form a heterodimer, with the Tfa1 (TFIIEα) WH binding the Pol II clamp and the Tfa2 (TFIIEβ) tandem WH domain encircling promoter DNA that becomes single-stranded in the open complex. Ssl2 lies adjacent to TFIIE, enclosing downstream promoter DNA. Unlike previous proposals, comparison of the PIC and open-complex models strongly suggests that Ssl2 promotes DNA opening by functioning as a double-stranded-DNA translocase, feeding 15 base pairs into the Pol II cleft. Right-handed threading of DNA through the Ssl2 binding groove, combined with the fixed position of upstream promoter DNA, leads to DNA unwinding and the open state.

Williams syndrome (WS), caused by a heterozygous microdeletion on chromosome 7q11.23, is a neurodevelopmental disorder characterized by hypersociability and neurocognitive abnormalities. Of the deleted genes, general transcription factor IIi (Gtf2i) has been linked to hypersociability in WS, although the underlying mechanisms are poorly understood. We show that selective deletion of Gtf2i in the excitatory neurons of the forebrain caused neuroanatomical defects, fine motor deficits, increased sociability and anxiety. Unexpectedly, 70% of the genes with significantly decreased messenger RNA levels in the mutant mouse cortex are involved in myelination, and mutant mice had reduced mature oligodendrocyte cell numbers, reduced myelin thickness and impaired axonal conductivity. Restoring myelination properties with clemastine or increasing axonal conductivity rescued the behavioral deficits. The frontal cortex from patients with WS similarly showed reduced myelin thickness, mature oligodendrocyte cell numbers and mRNA levels of myelination-related genes. Our study provides molecular and cellular evidence for myelination deficits in WS linked to neuronal deletion of Gtf2i.Barak et al. show that deletion of Gtf2i, a gene deleted in Williams syndrome, from the excitatory neurons of the forebrain reduced myelin thickness and axonal conduction. Rescuing myelination with a US Food and Drug Administration-approved drug restored normal behavior.

Giuseppe Giaccone and colleagues identify a recurrent missense mutation in GTF2I in a high percentage of thymic epithelial tumors. The mutation occurs more commonly in type A and AB thymomas and is associated with a more favorable clinical outcome. We analyzed 28 thymic epithelial tumors (TETs) using next-generation sequencing and identified a missense mutation (chromosome 7 c.74146970T>A) in GTF2I at high frequency in type A thymomas, a relatively indolent subtype. In a series of 274 TETs, we detected the GTF2I mutation in 82% of type A and 74% of type AB thymomas but rarely in the aggressive subtypes, where recurrent mutations of known cancer genes have been identified. Therefore, GTF2I mutation correlated with better survival. GTF2I β and δ isoforms were expressed in TETs, and both mutant isoforms were able to stimulate cell proliferation in vitro . Thymic carcinomas carried a higher number of mutations than thymomas (average of 43.5 and 18.4, respectively). Notably, we identified recurrent mutations of known cancer genes, including TP53 , CYLD , CDKN2A , BAP1 and PBRM1 , in thymic carcinomas. These findings will complement the diagnostic assessment of these tumors and also facilitate development of a molecular classification and assessment of prognosis and treatment strategies.

Higher‐order multi‐protein complexes such as RNA polymerase II (Pol II) complexes with transcription initiation factors are often not amenable to X‐ray structure determination. Here, we show that protein cross‐linking coupled to mass spectrometry (MS) has now sufficiently advanced as a tool to extend the Pol II structure to a 15‐subunit, 670 kDa complex of Pol II with the initiation factor TFIIF at peptide resolution. The N‐terminal regions of TFIIF subunits Tfg1 and Tfg2 form a dimerization domain that binds the Pol II lobe on the Rpb2 side of the active centre cleft near downstream DNA. The C‐terminal winged helix (WH) domains of Tfg1 and Tfg2 are mobile, but the Tfg2 WH domain can reside at the Pol II protrusion near the predicted path of upstream DNA in the initiation complex. The linkers between the dimerization domain and the WH domains in Tfg1 and Tfg2 are located to the jaws and protrusion, respectively. The results suggest how TFIIF suppresses non‐specific DNA binding and how it helps to recruit promoter DNA and to set the transcription start site. This work establishes cross‐linking/MS as an integrated structure analysis tool for large multi‐protein complexes.

During transcription initiation, Ssl2, the dsDNA translocase of TFIIH, opens a 6-bp DNA bubble, suggesting a two-step model wherein Ssl2 triggers a 6-bp open complex that RNA polymerase II expands via NTP-dependent RNA transcription. Eukaryotic mRNA transcription initiation is directed by the formation of the megadalton-sized preinitiation complex (PIC). After PIC formation, double-stranded DNA (dsDNA) is unwound to form a single-stranded DNA bubble, and the template strand is loaded into the polymerase active site. DNA opening is catalyzed by Ssl2 (XPB), the dsDNA translocase subunit of the basal transcription factor TFIIH. In yeast, transcription initiation proceeds through a scanning phase during which downstream DNA is searched for optimal start sites. Here, to test models for initial DNA opening and start-site scanning, we measure the DNA-bubble sizes generated by Saccharomyces cerevisiae PICs in real time using single-molecule magnetic tweezers. We show that ATP hydrolysis by Ssl2 opens a 6-base-pair (bp) bubble that grows to 13 bp in the presence of NTPs. These observations support a two-step model wherein ATP-dependent Ssl2 translocation leads to a 6-bp open complex that RNA polymerase II expands via NTP-dependent RNA transcription.

The transcriptional regulatory network governing the differentiation and functionality of oligodendrocytes (OLs) is essential for the formation and maintenance of the myelin sheath, and hence for the proper function of the nervous system. Perturbations in the intricate interplay of transcriptional effectors within this network can lead to a variety of nervous system pathologies. In this study, we identify Gtf2i -encoded general transcription factor II-I (Tfii-i) as a regulator of key myelination-related genes. Gtf2i deletion from myelinating glial cells in male mice leads to functional alterations in central nervous system (CNS) myelin, including elevated mRNA and protein expression levels of myelin basic protein (Mbp), the central myelin component, enhanced connectivity properties, and thicker myelin wrapping axons with increased diameters. These changes resulted in faster axonal conduction across the corpus callosum (CC), and improved motor coordination. Furthermore, we show that in mature OLs (mOLs), Tfii-i directly binds to regulatory elements of Sox10 and Mbp . In the peripheral nervous system (PNS), Gtf2i deletion from Schwann cells (SCs) leads to hypermyelination of the tibial branch of the sciatic nerve (SN). These findings add to our understanding of myelination regulation and specifically elucidate a cell-autonomous mechanism for Tfii-i in myelinating glia transcriptional network. The transcriptional regulation of oligodendrocytes has an essential role in myelin formation and maintenance. Here, the authors identify the transcription factor Tfii-i as a regulator of myelin genes expression in the nervous system and show that its loss enhances myelin thickness and nerve conduction.

Transcription initiation factor IIE subunit beta (GTF2E2) is a crucial component of the RNA polymerase II transcription initiation complex. There is a lack of more detailed research on the biological function of GTF2E2 in pan-cancer. We conducted a comprehensive pan-cancer analysis using data from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) project. Employing a multi-pronged approach with tools including R, Cytoscape, TISIDB, cBioPortal, STRING, GSCALite, and CancerSEA, we investigated GTF2E2's expression patterns, prognostic value, mutational landscape, functional enrichment, and immunological associations across 33 cancer types. Besides, we further validated the bioinformatic results through in vitro experiments in Uterine corpus endometrial carcinoma (UCEC), including western blotting (WB), cell proliferation assays and transwell. DCFH-DA, C11-BODIPY 581/591 and FeRhoNox-1 probes were performed to identify ferroptosis levels in vitro. GTF2E2 expression was significantly elevated in most cancers compared to normal tissues, with notable diagnostic potential (AUC > 0.7) in 20 cancer types. GTF2E2 expression varied across molecular and immune subtypes and correlated with tumor stage and patient age in several cancers. Functional enrichment analyses highlighted GTF2E2's involvement in key cancer-related and immunological pathways. Notably, GTF2E2 promoted UCEC progression in vitro, and knockdown of GTF2E2 significantly inhibited the proliferation, migration and invasion of UCEC cells. Compared with the control group, GPX4 expression was down-regulated and ACSL4 expression was up-regulated in the GTF2E2-knockdown group. Knockdown of GTF2E2 also increased the intracellular levels of Fe2+, lipid peroxides (LPOs) and reactive oxygen species (ROS). Our findings underscore GTF2E2's multifaceted roles in cancer biology, highlighting its potential as a diagnostic biomarker, prognostic indicator, and immunotherapeutic target across various malignancies. This investigation has the potential to contribute significantly to a deeper understanding of the substantial involvement of GTF2E2 in human malignancies, particularly UCEC.

Recent evidence suggests that transcript elongation by RNA polymerase II (RNAPII) is regulated by mechanical cues affecting the entry into, and exit from, transcriptionally inactive states, including pausing and arrest. We present a single-molecule optical-trapping study of the interactions of RNAPII with transcription elongation factors TFIIS and TFIIF, which affect these processes. By monitoring the response of elongation complexes containing RNAPII and combinations of TFIIF and TFIIS to controlled mechanical loads, we find that both transcription factors are independently capable of restoring arrested RNAPII to productive elongation. TFIIS, in addition to its established role in promoting transcript cleavage, is found to relieve arrest by a second, cleavage-independent mechanism. TFIIF synergistically enhances some, but not all, of the activities of TFIIS. These studies also uncovered unexpected insights into the mechanisms underlying transient pauses. The direct visualization of pauses at near-base-pair resolution, together with the load dependence of the pause-entry phase, suggests that two distinct mechanisms may be at play: backtracking under forces that hinder transcription and a backtrack-independent activity under assisting loads. The measured pause lifetime distributions are inconsistent with prevailing views of backtracking as a purely diffusive process, suggesting instead that the extent of backtracking may be modulated by mechanisms intrinsic to RNAPII. Pauses triggered by inosine triphosphate misincorporation led to backtracking, even under assisting loads, and their lifetimes were reduced by TFIIS, particularly when aided by TFIIF. Overall, these experiments provide additional insights into how obstacles to transcription may be overcome by the concerted actions of multiple accessory factors.