Functional Genomics Identifies Metabolic Vulnerabilities in Pancreatic Cancer

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Localization of proteins to the nucleus

Nuclear proteins are synthesized in the cytoplasm and must subsequently enter the nucleus. Recent experiments indicate some similarities and some differences between protein localization to the nucleus and localization to other organelles.     

Comparative taphonomy of three bivalve species from a mass shell accumulation in the intertidal regime of North Sea tidal flats

This study comprises a comparative taphonomic analysis of three endobenthic bivalves (Mya arenaria, Cerastoderma edule, and Macoma balthica) derived from a mass accumulation of mainly vertically packed shells from the “Wurster Watt” in Lower Saxony’s Wadden Sea, German Bight. Bulk samples from two transects were analyzed with respect to taxonomic composition, left/right valve presence, counts and weight percentages of taxa, and size-frequency distributions. Taphonomic features including abrasion, fragmentation, encrustation and bioerosion were subjected to a semi-quantitative analysis. Taphonomic results show significant differences with respect to bivalve taxa as well as between transects. Mya arenaria, a large endobenthic bivalve, shows the greatest amount of fragmentation and is often encrusted by balanids and bryozoans. The smaller and more robust Cerastoderma edule has the greatest values for bioerosion especially by the polychaete Polydora ciliata. Macoma balthica, which has the thinnest valves, shows the highest values for abrasion, but low values for the rest of the measured taphonomic features. Taphonomic differences between the taxa, samples and transects are related to (1) the origin of the bivalves (from living populations or exposed colonization horizons), (2) the different size and morphology of the valves (themselves related to mode of life), (3) the taphonomic trajectories of the different bivalves, as well as (4) the varying depositional environment of the two transects.     

Short-term boron deprivation enhances levels of cytoskeletal proteins in maize, but not zucchini, root apices

By using indirect immunofluorescence microscopy and Western blot analysis, we have demonstrated increased levels of actin and tubulin proteins as well as an altered polymerization pattern of their cytoskeletal assemblies in maize, but not zucchini root apices, as a response to early boron deprivation. Northern blot analysis, however, did not show significant increases in the amount of steady-state mRNAs of actin and tubulin. This finding indicates that these rapid cytoskeletal responses to boron removal are very likely regulated at translational/post-translational levels. Interestingly, these increased levels of cytoskeletal proteins coincided well with a reduction in the water-extractable, but not with the cell wall-bound, fraction of boron. This implicates that free boric acid, or other more labile boron complexes, might be involved in the activation of cytoskeletal responses in maize root apices. In fact, our experimental approach revealed that maize was suffering from boron deprivation as early as zucchini. This was evidenced by its slightly reduced root elongation rate recorded within 3–5 h of boron deprivation. Importantly, however, maize roots can recover from this early inhibition indicating an effective adaptation mechanism. In contrast, zucchini roots apparently lack this boron-deprivation response pathway and suffer extensively when exposed to boron-free environment. This leads to the tentative working hypothesis for an adaptive mechanism of maize roots to boron deprivation by enhancing its cytoskeletal protein levels and altering their polymerization patterns in order to mechanically reinforce the cell periphery complex of their cells. This testable hypothesis requires further experimental verification.     

Human Stem Cell-Derived Neurons Repair Circuits and Restore Neural Function

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