Publications by authors named "Rancour D"

Maternal vaccinations administered prior to conception or during pregnancy enhance the immune protection of newborn infants against many pathogens. A feasibility experiment was conducted to determine if monkeys can be used to model the placental transfer of maternal antibody against SARS-CoV-2. Six adult rhesus monkeys were immunized with adjuvanted recombinant-protein antigens comprised of receptor-binding domain human IgG1-Fc fusion proteins (RBD-Fc) containing protein sequences from the ancestral-Wuhan or Gamma variants.

View Article and Find Full Text PDF

Background: Progressive multifocal leukoencephalopathy (PML) is a rare and often lethal brain disorder caused by the common, typically benign polyomavirus 2, also known as JC virus (JCV). In a small percentage of immunosuppressed individuals, JCV is reactivated and infects the brain, causing devastating neurological defects. A wide range of immunosuppressed groups can develop PML, such as patients with: HIV/AIDS, hematological malignancies (e.

View Article and Find Full Text PDF

Introduction: Interferon-γ (IFN-γ) is an appealing target to evaluate immune response in cancer immunotherapy as it is a hallmark of an active immune system. Imaging and detection via immunopositron emission tomography (immunoPET) of this soluble cytokine has been made feasible using a Zr-labeled (t ~ 3.27 d) monoclonal antibody (mAb).

View Article and Find Full Text PDF

The purification of hydroxycinnamic acids [-coumaric acid (CA) and ferulic acid (FA)] from grass cell walls requires high-cost processes. Feedstocks with increased levels of one hydroxycinnamate in preference to the other are therefore highly desirable. We identified and conducted expression analysis for nine BAHD acyltransferase genes from sugarcane.

View Article and Find Full Text PDF

Background: Vaccines that generate robust and long-lived protective immunity against SARS-CoV-2 infection are urgently required.

Methods: We assessed the potential of vaccine candidates based on the SARS-CoV-2 spike in cynomolgus macaques () by examining their ability to generate spike binding antibodies with neutralizing activity. Antigens were derived from two distinct regions of the spike S1 subunit, either the N-terminal domain or an extended C-terminal domain containing the receptor-binding domain and were fused to the human IgG1 Fc domain.

View Article and Find Full Text PDF

Vaccines that generate robust and long-lived protective immunity against SARS-CoV-2 infection are urgently required. We assessed the potential of vaccine candidates based on the SARS-CoV-2 spike in cynomolgus macaques () by examining their ability to generate spike binding antibodies with neutralizing activity. Antigens were derived from two distinct regions of the spike S1 subunit, either the N-terminal domain (NTD) or an extended C-terminal domain containing the receptor-binding domain (RBD) and were fused to the human IgG1 Fc domain.

View Article and Find Full Text PDF

Cell wall matrices are complex composites mainly of polysaccharides, phenolics (monomers and polymers), and protein. We are beginning to understand the synthesis of these major wall components individually, but still have a poor understanding of how cell walls are assembled into complex matrices. Valuable insight has been gained by examining intact components to understand the individual elements that make up plant cell walls.

View Article and Find Full Text PDF

Nucleotide-activated sugars are essential substrates for plant cell-wall carbohydrate-polymer biosynthesis. The most prevalent grass cell wall (CW) sugars are glucose (Glc), xylose (Xyl), and arabinose (Ara). These sugars are biosynthetically related via the UDP-sugar interconversion pathway.

View Article and Find Full Text PDF

The microtubule plus-end tracking proteins (+TIPs) END BINDING1b (EB1b) and SPIRAL1 (SPR1) are required for normal cell expansion and organ growth. EB proteins are viewed as central regulators of +TIPs and cell polarity in animals; SPR1 homologs are specific to plants. To explore if EB1b and SPR1 fundamentally function together, we combined genetic, biochemical, and cell imaging approaches in Arabidopsis thaliana.

View Article and Find Full Text PDF

Grasses, such as Zea mays L. (maize), contain relatively high levels of p-coumarates (pCA) within their cell walls. Incorporation of pCA into cell walls is believed to be due to a hydroxycinnamyl transferase that couples pCA to monolignols.

View Article and Find Full Text PDF

Temperate perennial grasses are important worldwide as a livestock nutritive energy source and a potential feedstock for lignocellulosic biofuel production. The annual temperate grass Brachypodium distachyon has been championed as a useful model system to facilitate biological research in agriculturally important temperate forage grasses based on phylogenetic relationships. To physically corroborate genetic predictions, we determined the chemical composition profiles of organ-specific cell walls throughout the development of two common diploid accessions of Brachypodium distachyon, Bd21-3 and Bd21.

View Article and Find Full Text PDF

Escherichia coli is a frequently used expression system for the generation of protein encoded by genes from diverse kingdoms and, thus, it is well suited for the production of protein antigens for antibody generation. It is a system of choice for many due to factors such as (1) the commercial availability of a vast array of reagents and materials needed for cloning, expression, and purification and (2) the potential high protein yields that can be acquired in a timely and cost-effective manner. This chapter will focus on (1) the general principles to keep in mind when choosing an antigen to express and (2) the use of a modified pGEX vector system (Rancour et al.

View Article and Find Full Text PDF

CDC48/p97 is a conserved homohexameric AAA-ATPase chaperone required for a variety of cellular processes but whose role in the development of a multicellular model system has not been examined. Here, we have used reverse genetics, visualization of a functional Arabidopsis (Arabidopsis thaliana) CDC48 fluorescent fusion protein, and morphological analysis to examine the subcellular distribution and requirements for AtCDC48A in planta. Homozygous Atcdc48A T-DNA insertion mutants arrest during seedling development, exhibiting decreased cell expansion and displaying pleiotropic defects in pollen and embryo development.

View Article and Find Full Text PDF

CDC48/p97 is an essential AAA-ATPase chaperone that functions in numerous diverse cellular activities through its interaction with specific adapter proteins. The ubiquitin regulatory X (UBX)-containing protein, PUX1, functions to regulate the hexameric structure and ATPase activity of AtCDC48. To characterize the biochemical mechanism of PUX1 action on AtCDC48, we have defined domains of both PUX1 and AtCDC48 that are critical for interaction and oligomer disassembly.

View Article and Find Full Text PDF

Using a maskless photolithography method, we produced DNA oligonucleotide microarrays with probe sequences tiled throughout the genome of the plant Arabidopsis thaliana. RNA expression was determined for the complete nuclear, mitochondrial, and chloroplast genomes by tiling 5 million 36-mer probes. These probes were hybridized to labeled mRNA isolated from liquid grown T87 cells, an undifferentiated Arabidopsis cell culture line.

View Article and Find Full Text PDF

p97/CDC48 is a highly abundant hexameric AAA-ATPase that functions as a molecular chaperone in numerous diverse cellular activities. We have identified an Arabidopsis UBX domain-containing protein, PUX1, which functions to regulate the oligomeric structure of the Arabidopsis homolog of p97/CDC48, AtCDC48, as well as mammalian p97. PUX1 is a soluble protein that co-fractionates with non-hexameric AtCDC48 and physically interacts with AtCDC48 in vivo.

View Article and Find Full Text PDF

Dynamin-related GTPases regulate a wide variety of dynamic membrane processes in eukaryotes. Here, we investigated the function of ADL1C, a member of the Arabidopsis 68 kDa dynamin-like protein family. Analysis of heterozygous adl1C-1 indicates that the mutation specifically affects post-meiotic male gametogenesis.

View Article and Find Full Text PDF

The components of the cellular machinery that accomplish the various complex and dynamic membrane fusion events that occur at the division plane during plant cytokinesis, including assembly of the cell plate, are not fully understood. The most well-characterized component, KNOLLE, a cell plate-specific soluble N-ethylmaleimide-sensitive fusion protein (NSF)-attachment protein receptor (SNARE), is a membrane fusion machine component required for plant cytokinesis. Here, we show the plant ortholog of Cdc48p/p97, AtCDC48, colocalizes at the division plane in dividing Arabidopsis cells with KNOLLE and another SNARE, the plant ortholog of syntaxin 5, SYP31.

View Article and Find Full Text PDF

Dynamin and dynamin-like proteins are GTP-binding proteins involved in vesicle trafficking. In soybean, a 68-kD dynamin-like protein called phragmoplastin has been shown to be associated with the cell plate in dividing cells (Gu and Verma, 1996). Five ADL1 genes encoding dynamin-like proteins related to phragmoplastin have been identified in the completed Arabidopsis genome.

View Article and Find Full Text PDF

We tested the importance of the aspartate-any residue-aspartate (DXD) motif for the enzymatic activity and nucleotide binding capacity of the Golgi glycosyltransferase GM2 synthase. We prepared point mutations of the motif, which is found in the sequence 352-VLWVDDDFV, and analyzed cells that stably expressed the mutated proteins. Whereas the folding of the mutated proteins was not seriously disrupted as judged by assembly into homodimers, Golgi localization, and secretion of a soluble form of the enzyme, exchange of the highly conserved aspartic acid residues at position 356 or 358 with alanine or asparagine reduced enzyme activity to background levels.

View Article and Find Full Text PDF

Glycosylphosphatidylinositols (GPIs) are made by all eukaryotes. The first step in their synthesis is the transfer of GlcNAc from UDP-GlcNAc to phosphatidylinositol (PI). Four proteins in mammals and at least three in yeast make up a complex that carries out this reaction.

View Article and Find Full Text PDF

Glycosylation of glycoproteins, proteoglycans, and glycosphingolipids occurs mainly in the lumen of the endoplasmic reticulum and the Golgi apparatus. Nucleotide sugars, donors of all the sugars involved in Golgi glycosylation reactions, are synthesized in the cytoplasm and require specialized transporters to be translocated into the lumen of the Golgi apparatus. By controlling the supply of sugar nucleotides in the lumen of the Golgi apparatus, these transporters directly regulate the glycosylation of macromolecules transiting the Golgi.

View Article and Find Full Text PDF

Much of the enzymic machinery required for the assembly of cell surface carbohydrates is located in the endoplasmic reticulum (ER) of eukaryotic cells. Structural information on these proteins is limited and the identity of the active polypeptide(s) is generally unknown. This paper describes the synthesis and characteristics of a photoaffinity reagent that can be used to identify and analyse members of the ER glycan assembly apparatus, specifically those glycosyltransferases, nucleotide phosphatases and nucleotide-sugar transporters that recognize uridine nucleotides or UDP-sugars.

View Article and Find Full Text PDF