Publications by authors named "Taylor Stevens"

Hepatoblastoma (HB), the most common pediatric liver cancer, is associated with dysregulated Wnt/β-catenin, Hippo, and/or nuclear factor erythroid 2 ligand 2/nuclear respiratory factor 2 (NFE2L2/NRF2) pathways. In mice, pairwise combinations of oncogenically active forms of the terminal transcription factors of these pathways, namely, β-catenin (B), Yes-associated protein (YAP; Y), and Nrf2 (N), generated HBs, with the triple combination (B + Y + N) being particularly potent. Each tumor group alters the expression of thousands of B-, Y-, and N-driven unique and common target genes.

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Optimal gene transcription is achieved through precise interactions between transcription factors and their DNA binding sites. We provide evidence that conserved distally located 5'-flanking sequences interact directly with the intrinsically disordered amino-terminal region of the thyroid receptor-α (TRα) to control transcriptional activity. Simulated modeling and dynamics with multiple ChIP-seq-derived sequences consistently reveal specific lysine/arginine-DNA minor groove interactions.

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Article Synopsis
  • Mitochondrial function relies on properly positioned membrane proteins in the outer mitochondrial membrane, which features around 150 proteins predominantly made up of α-helical transmembrane domains.
  • The expansion of this family of proteins in metazoans is crucial for various processes like mitochondrial fusion, fission, and immune responses, highlighted by the role of MTCH2 as an important insertase.
  • The text introduces three experimental methods to study α-helical protein insertion: a split fluorescent reporter system for live cell monitoring, an approach for isolating functional mitochondria for lab assays, and a technique for reconstituting protein insertion using proteoliposomes with MTCH2, paving the way for deeper analysis of mitochondrial protein dynamics.
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The MYC oncoprotein regulates numerous genes involved in cellular processes such as cell cycle and mitochondrial and ribosomal structure and function. This requires heterodimerization with its partner, MAX, and binding to specific promoter and enhancer elements. Here, we show that MYC and MAX also bind near transcriptional end sites (TESs) of over one-sixth of all annotated genes.

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The "Mlx" and "Myc" transcription factor networks cross-communicate and share many common gene targets. Myc's activity depends upon its heterodimerization with Max, whereas the Mlx Network requires that the Max-like factor Mlx associate with the Myc-like factors MondoA or ChREBP. The current work demonstrates that body-wide Mlx inactivation, like that of Myc, accelerates numerous aging-related phenotypes pertaining to body habitus and metabolism.

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Article Synopsis
  • Mitochondrial outer membrane α-helical proteins are essential for communication between mitochondria and the cytoplasm, but their targeting and insertion processes are not fully understood.
  • A study using genome-wide CRISPRi screens identified key factors involved in the biogenesis of these proteins, revealing distinct pathways based on the proteins' topology.
  • Specific components like NAC and TTC1 play critical roles in how different types of membrane proteins are targeted and inserted, with TTC1 acting as a chaperone that aids in the solubilization and insertion of signal-anchored proteins into the mitochondria.
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The "Mlx" and "Myc" Networks share many common gene targets. Just as Myc's activity depends upon its heterodimerization with Max, the Mlx Network requires that the Max-like factor Mlx associate with the Myc-like factors MondoA or ChREBP. We show here that body-wide inactivation, like that of accelerates numerous aging-related phenotypes pertaining to body habitus and metabolism.

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The isolation of proteins in high yield and purity is a major bottleneck for the analysis of their three-dimensional structure, function and interactome. Here, we present a streamlined workflow for the rapid production of proteins or protein complexes using lentiviral transduction of human suspension cells, combined with highly specific nanobody-mediated purification and proteolytic elution. Application of the method requires prior generation of a plasmid coding for a protein of interest (POI) fused to an N- or C-terminal GFP or ALFA peptide tag using a lentiviral plasmid toolkit we have designed.

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Article Synopsis
  • Mitochondrial outer membrane α-helical proteins are essential for communication between mitochondria and the cytoplasm, but how they're targeted and inserted remains unclear.
  • A study used genome-wide CRISPRi screens to identify necessary mammalian biogenesis factors, revealing that different membrane proteins follow unique targeting pathways based on their structure.
  • Key findings include the role of NAC in targeting polytopic proteins and TTC1, a new chaperone, for signal-anchored proteins, highlighting a similar process to how proteins are managed in the endoplasmic reticulum.
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MYC proto-oncogene dysregulation alters metabolism, translation, and other functions in ways that support tumor induction and maintenance. Although Myc mice are healthier and longer-lived than control mice, the long-term ramifications of more complete Myc loss remain unknown. We now describe the chronic consequences of body-wide Myc inactivation initiated postnatally.

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Myc, a member of the "Myc Network" of bHLH-ZIP transcription factors, supervises proliferation, metabolism, and translation. It also engages in crosstalk with the related "Mlx Network" to co-regulate overlapping genes and functions. We investigated the consequences of stepwise conditional inactivation of Myc and Mlx in primary and SV40 T-antigen-immortalized murine embryonic fibroblasts (MEFs).

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In the mitochondrial outer membrane, α-helical transmembrane proteins play critical roles in cytoplasmic-mitochondrial communication. Using genome-wide CRISPR screens, we identified mitochondrial carrier homolog 2 (MTCH2), and its paralog MTCH1, and showed that it is required for insertion of biophysically diverse tail-anchored (TA), signal-anchored, and multipass proteins, but not outer membrane β-barrel proteins. Purified MTCH2 was sufficient to mediate insertion into reconstituted proteoliposomes.

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INTRODUCTION In eukaryotic cells, the selective bidirectional transport of macromolecules between the nucleus and cytoplasm occurs through the nuclear pore complex (NPC). Embedded in nuclear envelope pores, the ~110-MDa human NPC is an ~1200-Å-wide and ~750-Å-tall assembly of ~1000 proteins, collectively termed nucleoporins. Because of the NPC's eightfold rotational symmetry along the nucleocytoplasmic axis, each of the ~34 different nucleoporins occurs in multiples of eight.

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INTRODUCTION The subcellular compartmentalization of eukaryotic cells requires selective transport of folded proteins and protein-nucleic acid complexes. Embedded in nuclear envelope pores, which are generated by the circumscribed fusion of the inner and outer nuclear membranes, nuclear pore complexes (NPCs) are the sole bidirectional gateways for nucleocytoplasmic transport. The ~110-MDa human NPC is an ~1000-protein assembly that comprises multiple copies of ~34 different proteins, collectively termed nucleoporins.

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Cytomegalovirus (CMV) is a common chronic herpesvirus found in humans and numerous other mammalian species. In people, chronic viruses like CMV can alter overall health and immunity and pose a serious risk for those with an inadequate immune system. In addition, CMV plays an important role in animal health, and could affect the health of vulnerable populations, like endangered species.

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Contact-dependent growth inhibition (CDI) entails receptor-mediated delivery of CdiA-derived toxins into Gram-negative target bacteria. Using electron cryotomography, we show that each CdiA effector protein forms a filament extending ∼33 nm from the cell surface. Remarkably, the extracellular filament represents only the N-terminal half of the effector.

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This study investigated drill-specific head impact biomechanics in a Division 1 collegiate football team using the Head Impact Telemetry System (HITS). A total of 32,083 impacts were recorded across 2 years of practices. Precise tracking of instrumented athletes, head impacts, and drill participation allowed quantification of hits sustained per person per minute (H/P/M) for each specific drill.

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