mRNA translation is integral to pain, yet the key regulatory factors and their target mRNAs are unclear. Here, we uncover a mechanism that bridges noxious insults to multiple phases of translational control in murine sensory neurons. We find that a painful cue triggers repression of peptide chain elongation through activation of elongation factor 2 kinase (eEF2K).
View Article and Find Full Text PDFSensory neurons play pervasive roles throughout biology. In vitro studies to probe their functions hinge on the successful application of primary cell culture. Here, we present a protocol for the isolation and culture of mouse dorsal root ganglion neurons for imaging applications.
View Article and Find Full Text PDFAll steps of cryogenic electron-microscopy (cryo-EM) workflows have rapidly evolved over the last decade. Advances in both single-particle analysis (SPA) cryo-EM and cryo-electron tomography (cryo-ET) have facilitated the determination of high-resolution biomolecular structures that are not tractable with other methods. However, challenges remain.
View Article and Find Full Text PDFPreviously, we showed that high-resolution template matching can localize ribosomes in two-dimensional electron cryo-microscopy (cryo-EM) images of untilted cells with high precision (Lucas et al., 2021). Here, we show that comparing the signal-to-noise ratio (SNR) observed with 2DTM using different templates relative to the same cellular target can correct for local variation in noise and differentiate related complexes in focused ion beam (FIB)-milled cell sections.
View Article and Find Full Text PDFDuring spliceosome assembly, the 3' splice site is recognized by sequential U2AF2 complexes, first with Splicing Factor 1 (SF1) and second by the SF3B1 subunit of the U2 small nuclear ribonuclear protein particle. The U2AF2-SF1 interface is well characterized, comprising a U2AF homology motif (UHM) of U2AF2 bound to a U2AF ligand motif (ULM) of SF1. However, the structure of the U2AF2-SF3B1 interface and its importance for pre-mRNA splicing are unknown.
View Article and Find Full Text PDFIn addition to their central functions in translation, ribosomes can adopt inactive structures that are fully assembled yet devoid of mRNA. We describe how the abundance of idle eukaryotic ribosomes is influenced by a broad range of biological conditions spanning viral infection, nutrient deprivation, and developmental cues. Vacant ribosomes may provide a means to exclude ribosomes from translation while also shielding them from degradation, and the variable identity of factors that occlude ribosomes may impart distinct functionality.
View Article and Find Full Text PDFRecurrent outbreaks of novel zoonotic coronavirus (CoV) diseases in recent years have highlighted the importance of developing therapeutics with broad-spectrum activity against CoVs. Because all CoVs use -1 programmed ribosomal frameshifting (-1 PRF) to control expression of key viral proteins, the frameshift signal in viral mRNA that stimulates -1 PRF provides a promising potential target for such therapeutics. To test the viability of this strategy, we explored whether small-molecule inhibitors of -1 PRF in SARS-CoV-2 also inhibited -1 PRF in a range of bat CoVs-the most likely source of future zoonoses.
View Article and Find Full Text PDFProcessing bodies (p-bodies) are a prototypical phase-separated RNA-containing granule. Their abundance is highly dynamic and has been linked to translation. Yet, the molecular mechanisms responsible for coordinate control of the two processes are unclear.
View Article and Find Full Text PDFInjury responses require communication between different cell types in the skin. Sensory neurons contribute to inflammation and can secrete signaling molecules that affect non-neuronal cells. Despite the pervasive role of translational regulation in nociception, the contribution of activity-dependent protein synthesis to inflammation is not well understood.
View Article and Find Full Text PDFAlthough the elongating ribosome is an efficient helicase, certain mRNA stem-loop structures are known to impede ribosome movement along mRNA and stimulate programmed ribosome frameshifting via mechanisms that are not well understood. Using biochemical and single-molecule Förster resonance energy transfer (smFRET) experiments, we studied how frameshift-inducing stem-loops from mRNA and the transcript of Human Immunodeficiency Virus (HIV) perturb translation elongation. We find that upon encountering the ribosome, the stem-loops strongly inhibit A-site tRNA binding and ribosome intersubunit rotation that accompanies translation elongation.
View Article and Find Full Text PDFSystemic AA amyloidosis is a worldwide occurring protein misfolding disease of humans and animals. It arises from the formation of amyloid fibrils from the acute phase protein serum amyloid A. Here, we report the purification and electron cryo-microscopy analysis of amyloid fibrils from a mouse and a human patient with systemic AA amyloidosis.
View Article and Find Full Text PDFThe transcription elongation and pre-mRNA splicing factor Tat-SF1 associates with the U2 small nuclear ribonucleoprotein (snRNP) of the spliceosome. However, the direct binding partner and underlying interactions mediating the Tat-SF1-U2 snRNP association remain unknown. Here, we identified SF3b1 as a Tat-SF1-interacting subunit of the U2 snRNP.
View Article and Find Full Text PDFThese 5 practice-changing initiatives can help reduce the number of unwanted pregnancies and allow women to take more control of their reproductive health.
View Article and Find Full Text PDFUnlabelled: The goal of this study was to investigate the effects of a vocal loading challenge that combined prolonged speaking, in child-directed voice within a noisy environment, in older adults. An additional goal was to determine whether increased environmental humidity would attenuate the negative effects of this vocal loading challenge.
Method: Thirteen healthy subjects (five males and eight females; >65 years) completed a vocal loading challenge.
Splicing factor 1 (SF1) recognizes 3' splice sites of the major class of introns as a ternary complex with U2AF and U2AF splicing factors. A conserved SPSP motif in a coiled-coil domain of SF1 is highly phosphorylated in proliferating human cells and is required for cell proliferation. The UHM kinase 1 (UHMK1), also called KIS, double-phosphorylates both serines of this SF1 motif.
View Article and Find Full Text PDFU2AF homology motifs (UHM) that recognize U2AF ligand motifs (ULM) are an emerging family of protein-protein interaction modules. UHM-ULM interactions recur in pre-mRNA splicing factors including U2AF1 and SF3b1, which are frequently mutated in myelodysplastic syndromes. The core topology of the UHM resembles an RNA recognition motif and is often mistakenly classified within this large family.
View Article and Find Full Text PDFObjectives were to determine the effects of chromium propionate supplementation on growth performance, insulin and glucose metabolism, and carcass characteristics of beef cattle. Steers ( = 34) were stratified by BW and assigned to 1 of 2 treatments: 1) no supplemental Cr (Cont) or 2) 3 mg supplemental Cr·steer·d (CrP). Both supplements, Cont and CrP, were delivered via 0.
View Article and Find Full Text PDFU2AF homology motifs (UHMs) mediate protein-protein interactions with U2AF ligand motifs (ULMs) of pre-mRNA splicing factors. The UHM-containing alternative splicing factor CAPERα regulates splicing of tumor-promoting VEGF isoforms, yet the molecular target of the CAPERα UHM is unknown. Here we present structures of the CAPERα UHM bound to a representative SF3b155 ULM at 1.
View Article and Find Full Text PDFThe objective of this study was to investigate the ruminal bacterial communities as affected by monensin, haylage, and their interaction of feedlot cattle fed 60 % dried distillers grains with solubles in a replicated 4 × 4 Latin square design. Pyrosequencing analysis of the V1-V3 region (about 500 bp) of 16S rRNA gene from the four dietary treatments (3 treatment plus one control diets) collectively revealed 51 genera of bacteria within 11 phyla. Firmicutes and Bacteroidetes were the first and the second most predominant phyla, respectively, irrespective of the dietary treatments.
View Article and Find Full Text PDFIn dairy cows, an increase in plasma concentration of glucose-dependent insulinotropic polypeptide (GIP) is associated with an increase in metabolizable energy intake, but the role of GIP in energy partitioning of dairy cattle is not certain. The objective of this study was to examine the relationship between plasma GIP concentrations and energy partitioning toward milk production. Four mid-lactation, primiparous, rumen-fistulated Holstein-Friesian cows were fed a control diet of 55% forage and 45% concentrate [dry matter (DM) basis] in a 4×4 Latin square design with 4-wk periods.
View Article and Find Full Text PDFObjective: To investigate effects of low dietary vitamin A content on antibody responses in feedlot calves inoculated with an inactivated bovine coronavirus (BCoV) vaccine.
Animals: 40 feedlot calves.
Procedures: Calves were fed diets containing high (3,300 U/kg) or low (1,100 U/kg) amounts of vitamin A beginning on the day of arrival at a feedlot (day 0) and continuing daily until the end of the study (day 140).
Negative interactions of the acidity and S content of dried distillers grains with solubles (DDGS) have not been quantified. The objectives of this study were to determine the effects of dietary S, dietary acidity, and their interactions on growth, feed efficiency, ruminal H2S concentration, and apparent nutrient digestibility in lambs fed DDGS-based diets. To neutralize acidity, the DDGS was untreated or treated with 2% NaOH.
View Article and Find Full Text PDFMature Angus-cross beef cows (n = 228) were used to evaluate effects of prepartum dietary energy source on postnatal growth and carcass composition of progeny in a 2-yr study. Starting at approximately 160 d of gestation, cows were fed diets consisting of 1 of 3 primary energy sources: grass hay (HY), corn (CN), or dried corn distillers grains with solubles (DG). The CN and DG diets were limit-fed to achieve similar energy intakes as cows fed HY.
View Article and Find Full Text PDFDried distillers grains with solubles (DDGS) can decrease rumen pH because of their inherent acidity. Two replicated 4 × 4 Latin square experiments were conducted with ruminally fistulated heifers to determine the effects of dietary inclusion and NaOH treatment of DDGS on rumen metabolism. In Exp.
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