We have uncovered several new SMGs in ESCC and defined an alcohol consumption related mutational signature. TENM3 mutations and the TP53 hotspot mutation p.R213* are independent prognosticators for poor survival in ESCC.

Molecular hydrogels have attracted extensive research interest in recent years because of their inherent properties (e.g., formation by the self-assembly of small molecules and their gel-sol/sol-gel phase transitions can be easily manipulated by external stimulus). [1] They have shown great potential in fields such as three-dimensional (3D) cell culture [2] and controlled drug delivery. [3] During the formation of a molecular hydrogel, a small molecule (molecular hydrogelator) needs to selfassemble into a 3D matrix of nanofibers, nanorods, or nanospheres that can hold water molecules within the cavities of the 3D matrix. To form the 3D matrix, there should be strong or at least medium interactions between self-assembled nanostructures. Otherwise, nanostructures with weak interactions between them will only form dispersions or solutions in the aqueous phase. Actually, there are many examples of this kind of self-assembled system that lack strong interactions between the self-assembled structures. [4] This type of solution/dispersion containing self-assembled nanostructures could change to a hydrogel if the interaction between the nanostructures could be enhanced. For example, several groups have demonstrated that zinc and calcium ions can be used to cross-link self-assembled nanofibers to form molecular hydrogels. [5] In this study, we rationally designed a fusion protein with four binding sites and used the proteinpeptide interaction to enhance interactions between selfassembled nanofibers, thus leading to the formation of molecular hydrogels (Figure 1).There are only a few examples of polymeric hydrogels formed by specific protein-peptide interactions. [6] Specific protein-peptide interaction has also been used to direct selfassembly of peptide nanowires into micrometer-sized crystalline cubes. [7] However, there are no reports about the formation of molecular hydrogels through protein-peptide interactions up to now. As mentioned above, the formation of a 3D matrix is crucial to the formation of molecular hydrogels. To use protein-peptide interactions to enhance interfiber interactions to support 3D structures, fusion proteins with multiple binding sites are needed. These kinds of fusion proteins usually contain two parts, one for multimer formation and the other for peptide binding. However, these fusion proteins are usually in the balance between multimers with multiple binding sites and monomer with only one binding site. The dissociation constants of protein-peptide interactions are also usually in the micro-to millimolar range. It remains a challenge to develop a protein that can predominantly (> 95 %) form multimers with multiple binding sites. It would also be highly interesting for researchers in the field of biomaterials to develop a protein-peptide interaction with Figure 1. Protein-peptide interaction can be used to enhance interactions between self-assembled fibers, thus leading to molecular hydrogelation. A) Chemical structure of Nap-GFFYGGGWRESAI (1: nongelator) with a possible self-assembly a...

The highly conserved Paf1 complex (PAF1C) plays critical roles in RNA polymerase II transcription elongation and in the regulation of histone modifications. It has also been implicated in other diverse cellular activities, including posttranscriptional events, embryonic development and cell survival and maintenance of embryonic stem cell identity. Here, we report the structure of the human Paf1/Leo1 subcomplex within PAF1C. The overall structure reveals that the Paf1 and Leo1 subunits form a tightly associated heterodimer through antiparallel beta-sheet interactions. Detailed biochemical experiments indicate that Leo1 binds to PAF1C through Paf1 and that the Ctr9 subunit is the key scaffold protein in assembling PAF1C. Furthermore, we show that the Paf1/Leo1 heterodimer is necessary for its binding to histone H3, the histone octamer, and nucleosome in vitro. Our results shed light on the PAF1C assembly process and substrate recognition during various PAF1C-coordinated histone modifications.

Special AT-rich sequence-binding protein 1 (SATB1) is a global chromatin organizer and gene expression regulator essential for T-cell development and breast cancer tumor growth and metastasis. The oligomerization of the N-terminal domain of SATB1 is critical for its biological function. We determined the crystal structure of the N-terminal domain of SATB1. Surprisingly, this domain resembles a ubiquitin domain instead of the previously proposed PDZ domain. Our results also reveal that SATB1 can form a tetramer through its N-terminal domain. The tetramerization of SATB1 plays an essential role in its binding to highly specialized DNA sequences. Furthermore, isothermal titration calorimetry results indicate that the SATB1 tetramer can bind simultaneously to two DNA targets. Based on these results, we propose a molecular model whereby SATB1 regulates the expression of multiple genes both locally and at a distance.

The evolutionarily conserved multifunctional polymerase-associated factor 1 (Paf1) complex (Paf1C), which is composed of at least five subunits (Paf1, Leo1, Ctr9, Cdc73, and Rtf1), plays vital roles in gene regulation and has connections to development and human diseases. Here, we report two structures of each of the human and yeast Ctr9/Paf1 subcomplexes, which assemble into heterodimers with very similar conformations, revealing an interface between the tetratricopeptide repeat module in Ctr9 and Paf1. The structure of the Ctr9/Paf1 subcomplex may provide mechanistic explanations for disease-associated mutations in human PAF1 and CTR9. Our study reveals that the formation of the Ctr9/Paf1 heterodimer is required for the assembly of yeast Paf1C, and is essential for yeast viability. In addition, disruption of the interaction between Paf1 and Ctr9 greatly affects the level of histone H3 methylation in vivo. Collectively, our results shed light on Paf1C assembly and functional regulation.

Elongator is a highly conserved multiprotein complex composed of six subunits (Elp1-6). Elongator has been associated with various cellular activities and has attracted clinical attention because of its role in certain neurodegenerative diseases. Here, we present the crystal structure of the Elp2 subunit revealing two seven-bladed WD40 β propellers, and show by structure-guided mutational analyses that the WD40 fold integrity of Elp2 is necessary for its binding to Elp1 and Elp3 subunits in multiple species. The detailed biochemical experiments indicate that Elp2 binds microtubules through its conserved alkaline residues in vitro and in vivo. We find that both the mutually independent Elp2-mediated Elongator assembly and the cytoskeleton association are important for yeast viability. In addition, mutation of Elp2 greatly affects the histone H3 acetylation activity of Elongator in vivo. Our results indicate that Elp2 is a necessary component for functional Elongator and acts as a hub in the formation of various complexes.

Abstract. The purpose of this study was to develop an injectable in situ liquid crystal formulation for intraarticular (IA) administration, and in situ forming a viscous liquid crystalline gel with long-term release of sinomenine hydrochloride (SMH) upon water absorption. The pseudo-ternary phase diagram of phytantriol (PT)-ethanol (ET)-water was constructed, and isotropic solutions were chosen for further optimization. The physicochemical properties of isotropic solutions were evaluated, and the phase structures of liquid crystalline gels formed by isotropic solutions in excess water were confirmed by crossed polarized light microscopy (CPLM) and small-angle X-ray scattering (SAXS). In vitro drug release studies were conducted by using a dialysis membrane diffusion method. The optimal in situ cubic liquid crystal (ISV 2 ) (PT/ET/water, 64:16:20, w/w/w) loaded with 6 mg/g of SMH showed a suitable pH, showed to be injectable, and formed a cubic liquid crystalline gel in situ with minimum water absorption within the shortest time. The optimal ISV 2 was able to sustain the drug release for 6 days. An in situ hexagonal liquid crystal (ISH 2 ) system was prepared by addition of 5% vitamin E acetate (VitEA) into PT in the optimal ISV 2 system to improve the sustained release of SMH. This ISH 2 (PT/VitEA/ET/water, 60.8:3.2:16:20, w/w/w/w) was an injectable isotropic solution with a suitable pH range. The developed ISH 2 was found to be able to sustain the drug release for more than 10 days and was suitable for IA injection for the treatment of rheumatoid arthritis (RA).KEY WORDS: in situ cubic liquid crystal; in situ hexagonal liquid crystal; phytantriol; sinomenine hydrochloride; sustained drug release.

Gel nach Maß: Das Fusionsprotein ULD‐TIP‐1 aus der Ubiquitin‐artigen Domäne (ULD) und dem Tax‐bindenden Protein 1 (TIP‐1) verstärkt die Wechselwirkungen zwischen Fasern, die aus Bausteinen mit einem spezifisch an ULD‐TIP‐1 bindenden Peptid gebildet werden. Die mechanischen Eigenschaften der resultierenden Hydrogele (siehe Bild) lassen sich einstellen, indem man Peptide mit unterschiedlichen Dissoziationskonstanten bezüglich des Proteins verwendet.