283 research outputs found
Functional characterization and discovery of modulators of SbMATE, the agronomically important aluminium tolerance transporter from Sorghum bicolor.
About 50% of the world's arable land is strongly acidic (pH ≤ 5). The low pH solubilizes root-toxic ionic aluminium (Al3+) species from clay minerals, driving the evolution of counteractive adaptations in cultivated crops. The food crop Sorghum bicolor upregulates the membrane-embedded transporter protein SbMATE in its roots. SbMATE mediates efflux of the anionic form of the organic acid, citrate, into the soil rhizosphere, chelating Al3+ ions and thereby imparting Al-resistance based on excluding Al+3 from the growing root tip. Here, we use electrophysiological, radiolabeled, and fluorescence-based transport assays in two heterologous expression systems to establish a broad substrate recognition profile of SbMATE, showing the proton and/or sodium-driven transport of 14C-citrate anion, as well as the organic monovalent cation, ethidium, but not its divalent analog, propidium. We further complement our transport assays by measuring substrate binding to detergent-purified SbMATE protein. Finally, we use the purified membrane protein as an antigen to discover native conformation-binding and transport function-altering nanobodies using an animal-free, mRNA/cDNA display technology. Our results demonstrate the utility of using Pichia pastoris as an efficient eukaryotic host to express large quantities of functional plant transporter proteins. The nanobody discovery approach is applicable to other non-immunogenic plant proteins
Development, Application, and Transition of Aerosol and Trace Gas Products Derived from Next-Generation Satellite Observations to Operations
NASA Short-term Prediction Research and Transition (SPoRT) Center has a history of successfully transitioning unique observations and research capabilities to the operational weather community to improve short-term forecasts. SPoRTstrives to bridge the gap between research and operations by maintaining interactive partnerships with end users to develop products that match specific forecast challenges, provide training, and assess the products in the operational environment. This presentation focuses on recent product development, application, and transition of aerosol and trace gas products to operations for specific forecasting applications. Recent activities relating to the SPoRT ozone products, aerosol optical depth composite product, sulfur dioxide, and aerosol index products are discussed
Structure of an atypical FeoB G-domain reveals a putative domain-swapped dimer.
FeoB is a transmembrane protein involved in ferrous iron uptake in prokaryotic organisms. FeoB comprises a cytoplasmic soluble domain termed NFeoB and a C-terminal polytopic transmembrane domain. Recent structures of NFeoB have revealed two structural subdomains: a canonical GTPase domain and a five-helix helical domain. The GTPase domain hydrolyses GTP to GDP through a well characterized mechanism, a process which is required for Fe(2+) transport. In contrast, the precise role of the helical domain has not yet been fully determined. Here, the structure of the cytoplasmic domain of FeoB from Gallionella capsiferriformans is reported. Unlike recent structures of NFeoB, the G. capsiferriformans NFeoB structure is highly unusual in that it does not contain a helical domain. The crystal structures of both apo and GDP-bound protein forms a domain-swapped dimer
Getting Experimental Data to End Users via a Research to Operations Paradigm
No abstract availabl
The structural basis of bacterial manganese import
肺炎球菌が細胞内にマンガンイオンを取り込むしくみ --膜輸送体PsaBCの立体構造の解明--. 京都大学プレスリリース. 2021-09-15.Metal ions are essential for all forms of life. In prokaryotes, ATP-binding cassette (ABC) permeases serve as the primary import pathway for many micronutrients including the first-row transition metal manganese. However, the structural features of ionic metal transporting ABC permeases have remained undefined. Here, we present the crystal structure of the manganese transporter PsaBC from Streptococcus pneumoniae in an open-inward conformation. The type II transporter has a tightly closed transmembrane channel due to “extracellular gating” residues that prevent water permeation or ion reflux. Below these residues, the channel contains a hitherto unreported metal coordination site, which is essential for manganese translocation. Mutagenesis of the extracellular gate perturbs manganese uptake, while coordination site mutagenesis abolishes import. These structural features are highly conserved in metal-specific ABC transporters and are represented throughout the kingdoms of life. Collectively, our results define the structure of PsaBC and reveal the features required for divalent cation transport
On the nature of disks at high redshift seen by JWST/CEERS with contrastive learning and cosmological simulations
Visual inspections of the first optical rest-frame images from JWST have
indicated a surprisingly high fraction of disk galaxies at high redshifts. Here
we alternatively apply self-supervised machine learning to explore the
morphological diversity at . Our proposed data-driven representation
scheme of galaxy morphologies, calibrated on mock images from the TNG50
simulation, is shown to be robust to noise and to correlate well with physical
properties of the simulated galaxies, including their 3D structure. We apply
the method simultaneously to F200W and F356W galaxy images of a mass-complete
sample () at from the first JWST/NIRCam CEERS data
release. We find that the simulated and observed galaxies do not populate the
same manifold in the representation space from contrastive learning, partly
because the observed galaxies tend to be more compact and more elongated than
the simulated galaxies. We also find that about half the galaxies that were
visually classified as disks based on their elongated images actually populate
a similar region of the representation space than spheroids, which according to
the TNG50 simulation is occupied by objects with low stellar specific angular
momentum and non-oblate structure. This suggests that the disk fraction at as evaluated by visual classification may be severely overestimated by
misclassifying compact, elongated galaxies as disks. Deeper imaging and/or
spectroscopic follow-ups as well as comparisons with other simulations will
help to unambiguously determine the true nature of these galaxies.Comment: 25 pages, 23 figures. Submitted to ApJ. Comments welcom
Stromal‐Derived Factor‐1α (CXCL12) Levels Increase in Periodontal Disease
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142300/1/jper0845.pd
Whole genome landscapes of uveal melanoma show an ultraviolet radiation signature in iris tumours
Uveal melanoma (UM) is the most common intraocular tumour in adults and despite surgical or radiation treatment of primary tumours, ~50% of patients progress to metastatic disease. Therapeutic options for metastatic UM are limited, with clinical trials having little impact. Here we perform whole-genome sequencing (WGS) of 103 UM from all sites of the uveal tract (choroid, ciliary body, iris). While most UM have low tumour mutation burden (TMB), two subsets with high TMB are seen; one driven by germline MBD4 mutation, and another by ultraviolet radiation (UVR) exposure, which is restricted to iris UM. All but one tumour have a known UM driver gene mutation (GNAQ, GNA11, BAP1, PLCB4, CYSLTR2, SF3B1, EIF1AX). We identify three other significantly mutated genes (TP53, RPL5 and CENPE)
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