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The synthesis of ATP, life's "universal energy currency," is the most prevalent chemical reaction in biological systems and is responsible for fueling nearly all cellular processes, from nerve impulse propagation to DNA synthesis. ATP synthases, the family of enzymes that carry out this endless task, are nearly as ubiquitous as the energy-laden molecule they are responsible for making. The F-type ATP synthase (F-ATPase) is found in every domain of life and has facilitated the survival of organisms in a wide range of habitats, ranging from the deep-sea thermal vents to the human intestine. Accordingly, there has been a large amount of work dedicated toward understanding the structural and functional details of ATP synthases in a wide range of species. Less attention, however, has been paid toward integrating these advances in ATP synthase molecular biology within the context of its evolutionary history. In this review, we present an overview of several structural and functional features of the F-type ATPases that vary across taxa and are purported to be adaptive or otherwise evolutionarily significant: ion channel selectivity, rotor ring size and stoichiometry, ATPase dimeric structure and localization in the mitochondrial inner membrane, and interactions with membrane lipids. We emphasize the importance of studying these features within the context of the enzyme's particular lipid environment. Just as the interactions between an organism and its physical environment shape its evolutionary trajectory, ATPases are impacted by the membranes within which they reside. We argue that a comprehensive understanding of the structure, function, and evolution of membrane proteins-including ATP synthase-requires such an integrative approach.

Gene and cell therapy products approved over the past decade in Europe and North America have provided new therapeutic options for single gene disorders and for hematologic malignancies. Lessons learned, and limitations identified, are reviewed.

Protein S-palmitoylation, or S-fatty-acylation, regulates many fundamental cellular processes in eukaryotes. Herein, we present a chemical fatty-acylation approach that involves site-specific incorporation of cycloalkyne-containing unnatural amino acids and subsequent bioorthogonal reactions with fatty-acyl tetrazines to install fatty-acylation mimics at target protein sites, allowing gain-of-function analysis of S-palmitoylation in live cells.

Hepatitis C virus (HCV) has no animal reservoir, infecting only humans. To investigate species barrier determinants limiting infection of rodents, murine liver complementary DNA library screening was performed, identifying transmembrane proteins Cd302 and Cr1l as potent restrictors of HCV propagation. Combined ectopic expression in human hepatoma cells impeded HCV uptake and cooperatively mediated transcriptional dysregulation of a noncanonical program of immunity genes. Murine hepatocyte expression of both factors was constitutive and not interferon inducible, while differences in liver expression and the ability to restrict HCV were observed between the murine orthologs and their human counterparts. Genetic ablation of endogenous Cd302 expression in human HCV entry factor transgenic mice increased hepatocyte permissiveness for an adapted HCV strain and dysregulated expression of metabolic process and host defense genes. These findings highlight human-mouse differences in liver-intrinsic antiviral immunity and facilitate the development of next-generation murine models for preclinical testing of HCV vaccine candidates.

Objectives: Screening for genes differentially expressed in placental tissues, aiming to identify transcriptional signatures that may be involved in ZIKV congenital pathogenesis. Methods: Transcriptome data from placental tissues of pregnant women naturally infected with Zika virus during the third trimester were compared to those from women who tested negative for Zika infection. The findings were validated using both a cell culture model and an immunohistochemistry/morphological analysis of naturally infected placental tissues. Results: Transcriptome analysis revealed that Zika virus infection induces downregulation of insulin-like growth factor II (IGF2) gene, an essential factor for fetal development. The Caco-2 cell culture model that constitutively expresses IGF2 was used for the transcriptome validation. Asiatic and African Zika virus strains infection caused downregulated IGF2 gene expression in Caco-2 cells, whereas other flaviviruses, such as dengue serotype 1, West Nile and wild-type yellow fever viruses, had no effect on this gene expression. Immunohistochemical assays on decidual tissues corroborated our transcriptome analysis, showing that IGF2 is reduced in the decidua of Zika virus-infected women. Conclusions: Our results draw attention to IGF2 modulation in uterine tissues, and this finding is expected to support future studies on strategies to ameliorate the harmful effects of Zika virus infection during pregnancy. (C) 2020 The Author(s). Published by Elsevier Ltd on behalf of The British Infection Association.

The gene expression program underlying the specification of human cell types is of fundamental interest. We generated human cell atlases of gene expression and chromatin accessibility in fetal tissues. For gene expression, we applied three-level combinatorial indexing to >110 samples representing 15 organs, ultimately profiling similar to 4 million single cells. We leveraged the literature and other atlases to identify and annotate hundreds of cell types and subtypes, both within and across tissues. Our analyses focused on organ-specific specializations of broadly distributed cell types (such as blood, endothelial, and epithelial), sites of fetal erythropoiesis (which notably included the adrenal gland), and integration with mouse developmental atlases (such as conserved specification of blood cells). These data represent a rich resource for the exploration of in vivo human gene expression in diverse tissues and cell types.

Polarized growth requires the integration of polarity pathways with the delivery of exocytic vesicles for cell expansion and counterbalancing endocytic uptake. In budding yeast, the myosin-V Myo2 is aided by the kinesin-related protein Smy1 in carrying out the essential Sec4-dependent transport of secretory vesicles to sites of polarized growth. Overexpression suppressors of a conditional myo2 smy1 mutant identified a novel F-BAR (Fes/CIP4 homology-Bin-Amphiphysin-Rvs protein)-containing RhoGAP, Rgd3, that has activity primarily on Rho3, but also Cdc42. Internally tagged Rho3 is restricted to the plasma membrane in a gradient corresponding to cell polarity that is altered upon Rgd3 overexpression. Rgd3 itself is localized to dynamic polarized vesicles that, while distinct from constitutive secretory vesicles, are dependent on actin and Myo2 function. In vitro Rgd3 associates with liposomes in a PIP2-enhanced manner. Further, the Rgd3 C-terminal region contains several phosphorylatable residues within a reported SH3-binding motif. An unphosphorylated mimetic construct is active and highly polarized, while the phospho-mimetic form is not. Rgd3 is capable of activating Myo2, dependent on its phospho state, and Rgd3 overexpression rescues aberrant Rho3 localization and cell morphologies seen at the restrictive temperature in the myo2 smy1 mutant. We propose a model where Rgd3 functions to modulate and maintain Rho3 polarity during growth.

The advance of science is dependent upon collaboration, which does not have a visa attached to it. Indeed, over 40% of all American-based Nobel Prize winners are immigrants, and data from the National Science Foundation show that 49% of postdocs and 29% of science and engineering faculty in the US are foreign-born. However, restrictive new immigration policies in the US have left many scientists deeply concerned about their future and many American-based laboratories worried about attracting the best talent. At JEM, we're celebrating immigration by sharing the experiences of immigrant and nonimmigrant scientists on our editorial board. Alexander Rudensky and Jean-Laurent Casanova give their firsthand perspective on immigrating to the US, while JeddWolchok, Carl Nathan, David Holtzman, Susan Kaech, Lewis Lanier, and David Tuveson reflect on how immigration has affected their laboratories.

Recent years have seen a surge in methods to track and analyze animal behavior. Nevertheless, tracking individuals in closely interacting, group-living organisms remains a challenge. Here, we present anTraX, an algorithm and software package for high-throughput video tracking of color-tagged insects. anTraX combines neural network classification of animals with a novel approach for representing tracking data as a graph, enabling individual tracking even in cases where it is difficult to segment animals from one another, or where tags are obscured. The use of color tags, a well-established and robust method for marking individual insects in groups, relaxes requirements for image size and quality, and makes the software broadly applicable. anTraX is readily integrated into existing tools and methods for automated image analysis of behavior to further augment its output. anTraX can handle large-scale experiments with minimal human involvement, allowing researchers to simultaneously monitor many social groups over long time periods.

Keloids are disfiguring, fibroproliferative growths and their pathogenesis remains unclear, inhibiting therapeutic development. Available treatment options have limited efficacy and harbor safety concerns. Thus, there is a great need to clarify keloid pathomechanisms that may lead to novel treatments. In this study, we aimed to elucidate the profile of lesional and non-lesional keloid skin compared to normal skin. We performed gene (RNAseq, qRT-PCR) and protein (immunohistochemistry) expression analyses on biopsy specimens obtained from lesional and non-lesional skin of African American (AA) keloid patients compared to healthy skin from AA controls. Fold-change >= 2 and false-discovery rate (FDR)<0.05 was used to define significance. We found that lesional versus normal skin showed significant up-regulation of markers of T-cell activation/migration (ICOS, CCR7), Th2- (IL-4R, CCL11, TNFSF4/OX40L), Th1- (CXCL9/CXCL10/CXCL11), Th17/Th22- (CCL20, S100As) pathways, and JAK/STAT-signaling (JAK3) (false-discovery rate [FDR]<0.05). Non-lesional skin also exhibited similar trends. We observed increased cellular infiltrates in keloid tissues, including T-cells, dendritic cells, mast cells, as well as greater IL-4r alpha(+), CCR9(+), and periostin(+) immunostaining. In sum, comprehensive molecular profiling demonstrated that both lesional and non-lesional skin show significant immune alternations, and particularly Th2 and JAK3 expression. This advocates for the investigation of novel treatments targeting the Th2 axis and/or JAK/STAT-signaling in keloid patients.