The molecular mechanisms underpinning the formation of the large, ellipsoidal starch granules of potato tuber are poorly understood. Here, we demonstrate the distinct effects of PROTEIN TARGETING TO STARCH2b (PTST2b) and MYOSIN RESEMBLING CHLOROPLAST PROTEIN (MRC) on tuber starch granule morphology. A gene duplication event in the Solanaceae resulted in two PTST2 paralogs (PTST2a and PTST2b).
View Article and Find Full Text PDFSeed vigour and longevity are intricate yet indispensable physiological traits for agricultural crops, as they play a crucial role in facilitating the successful emergence of seedlings and exert a substantial influence on crop productivity. Transcriptional regulation plays an important role in seed development, maturation, and desiccation tolerance, which are important attributes for seed vigour and longevity. Here, we have investigated the regulatory role of the seed-specific DNA-binding with One Finger (DOF) transcription factor and the rice prolamin box binding factor (RPBF) in seed vigour.
View Article and Find Full Text PDFThe protein-repairing enzyme (PRE) PROTEIN L-ISOASPARTYL METHYLTRANSFERASE (PIMT) influences seed vigor by repairing isoaspartyl-mediated protein damage in seeds. However, PIMTs function in other seed traits, and the mechanisms by which PIMT affects such seed traits are still poorly understood. Herein, through molecular, biochemical, and genetic studies using overexpression and RNAi lines in Oryza sativa and Arabidopsis thaliana, we demonstrate that PIMT not only affects seed vigor but also affects seed size and weight by modulating enolase (ENO) activity.
View Article and Find Full Text PDFIntroduction: Infectious Bursal Disease Virus (IBDV) causes immunosuppression in chickens. While B-cell destruction is the main cause of humoral immunosuppression, bursal T cells from IBDV-infected birds have been reported to inhibit the mitogenic response of splenocytes, indicating that some T cell subsets in the infected bursa have immunomodulatory activities. CD4CD25TGFβ cells have been recently described in chickens that have immunoregulatory properties and play a role in the pathogenesis of Marek's Disease Virus.
View Article and Find Full Text PDFMarek's disease virus (MDV) causes a deadly lymphoproliferative disease in chickens, resulting in huge economic losses in the poultry industry. It has been suggested that MDV suppresses the induction of type I interferons and thus escapes immune control. Cholesterol 25-hydroxylase (CH25H), a gene that encodes an enzyme that catalyses cholesterol to 25-hydroxycholesterol (25-HC), is an interferon-stimulating gene (ISG) known to exert antiviral activities.
View Article and Find Full Text PDFThe plastidial α-glucan phosphorylase (PHS1) can elongate and degrade maltooligosaccharides (MOSs), but its exact physiological role in plants is poorly understood. Here, we discover a specialized role of PHS1 in establishing the unique bimodal characteristic of starch granules in wheat (Triticum spp.) endosperm.
View Article and Find Full Text PDFF-box proteins have diverse functions in eukaryotic organisms, including plants, mainly targeting proteins for 26S proteasomal degradation. Here, we demonstrate the role of the F-box protein SKP1-INTERACTING PARTNER 31 (SKIP31) from Arabidopsis (Arabidopsis thaliana) in regulating late seed maturation events, seed vigor, and viability through biochemical and genetic studies using skip31 mutants and different transgenic lines. We show that SKIP31 is predominantly expressed in seeds and that SKIP31 interacts with JASMONATE ZIM DOMAIN (JAZ) proteins, key repressors in jasmonate (JA) signaling, directing their ubiquitination for proteasomal degradation independently of coronatine/jasmonic acid-isoleucine (JA-Ile), in contrast to CORONATINE INSENSITIVE 1, which sends JAZs for degradation in a coronatine/JA-Ile dependent manner.
View Article and Find Full Text PDFTargeted radionuclide therapy (TRT) is an emerging therapeutic modality for the treatment of various solid cancers. Current approaches rely on the presence of cancer-specific epitopes and receptors against which a radiolabeled ligand is systemically administered to specifically deliver cytotoxic doses of α and β particles to tumors. In this proof-of-concept study, tumor-colonizing Escherichia coli Nissle 1917 (EcN) is utilized to deliver a bacteria-specific radiopharmaceutical to solid tumors in a cancer-epitope independent manner.
View Article and Find Full Text PDFThe need to develop new treatments to prevent unprompted premature delivery before 37 weeks of pregnancy remains pressing and unmet. Bacteria ( species) that promote vaginal health produce biochemical compounds that prevent the growth of microbes such as . Overgrowth of can cause vaginal infection with smelly discharge and increase a woman's risk of sexually transmitted infections and premature delivery.
View Article and Find Full Text PDFOxidation of methionine leads to the formation of methionine S-sulfoxide and methionine R-sulfoxide, which can be reverted by two types of methionine sulfoxide reductase (MSR): MSRA and MSRB. Though the role of MSR enzymes has been elucidated in various physiological processes, the regulation and role of MSR in seeds remains poorly understood. In this study, through molecular, biochemical, and genetic studies using seed-specific overexpression and RNAi lines of OsMSRB5 in Oryza sativa, we demonstrate the role of OsMSRB5 in maintaining seed vigor and longevity.
View Article and Find Full Text PDFArabidopsis ABSCISIC ACID INSENSITIVE4 (ABI4) positively regulates the protein repairing enzyme (PRE) PROTEIN L-ISOASPARTYL METHYLTRANSFERASE1 (PIMT1) in seed for its implication in seed vigor and longevity. PROTEIN L-ISOASPARTYL METHYLTRANSFERASE (PIMT) is a protein repairing enzyme (PRE) and is implicated in seed vigor and longevity. PIMT has been shown to be induced by ABA, however, its detailed regulation by ABA signaling components is unknown.
View Article and Find Full Text PDFExtracellular electron transfer (EET) - the process by which microorganisms transfer electrons across their membrane(s) to/from solid-phase materials - has implications for a wide range of biogeochemically important processes in marine environments. Though EET is thought to play an important role in the oxidation of inorganic minerals by lithotrophic organisms, the mechanisms involved in the oxidation of solid particles are poorly understood. To explore the genetic basis of oxidative EET, we utilized genomic analyses and transposon insertion mutagenesis screens (Tn-seq) in the metabolically flexible, lithotrophic Alphaproteobacterium ElOx9.
View Article and Find Full Text PDFIn contrast to desiccation-tolerant orthodox seeds, recalcitrant seeds are desiccation sensitive and are unable to survive for a prolonged time. Here, our analyses of Oryza species with contrasting seed desiccation tolerance reveals that PROTEIN L-ISOASPARTYL METHYLTRANSFERASE (PIMT), an enzyme that repairs abnormal isoaspartyl (isoAsp) residues in proteins, acts as a key player that governs seed desiccation tolerance to orthodox seeds but is ineffective in recalcitrant seeds. We observe that, unlike the orthodox seed of Oryza sativa, desiccation intolerance of the recalcitrant seeds of Oryza coarctata are linked to reduced PIMT activity and increased isoAsp accumulation due to the lack of coordinated action of ABA and ABI transcription factors to upregulate PIMT during maturation.
View Article and Find Full Text PDFMarek's disease virus (MDV), an avian alphaherpesvirus, infects chickens, transforms CD4+ T cells, and induces immunosuppression early during infection. However, the exact mechanisms involved in MDV-induced immunosuppression are yet to be identified. Here, our results demonstrate that MDV infection and induces activation of cyclooxygenase-2 (COX-2) and production of prostaglandin E2 (PGE2).
View Article and Find Full Text PDFDesmoplastic solid tumors are characterized by the rapid build-up of extracellular matrix (ECM) macromolecules, such as hyaluronic acid (HA). The resulting physiological barrier prevents the infiltration of immune cells and also impedes the delivery of anticancer agents. The development of a hypervesiculating Escherichia coli Nissle (ΔECHy) based tumor targeting bacterial system capable of distributing a fusion peptide, cytolysin A (ClyA)-hyaluronidase (Hy) via outer membrane vesicles (OMVs) is reported.
View Article and Find Full Text PDFGalactinol synthase (GolS) catalyzes the key regulatory step in the biosynthesis of Raffinose Family Oligosaccharides (RFOs). Even though the physiological role and regulation of this enzyme has been well studied, little is known about active site amino acids and the structure-function relationship with substrates of this enzyme. In the present study, we investigate the active site amino acid and structure-function relationship for this enzyme.
View Article and Find Full Text PDFThere is an emerging need for accurate and rapid identification of bacteria in the human body to achieve diverse biomedical objectives. Copper homeostasis is vital for the survival of bacterial species owing to the roles of the metal as a nutrient, respiratory enzyme cofactor, and a toxin. Here, we report the development of a copper-64-labeled bacterial metal chelator, yersiniabactin, to exploit a highly conserved metal acquisition pathway for noninvasive and selective imaging of bacteria.
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