Purpose: Under different abiotic-stress conditions, the unicellular green microalga Dunaliella salina accumulates large amounts of carotenoids which are accompanied by fatty acid biosynthesis. Carotenoids and fatty acids both possess long carbon backbones; however, the relationship between carotenoid and fatty acid metabolism is controversial and remains poorly understood in microalgae. Methods: In this study, we investigated the growth curves and the β-carotene, lutein, lipid, and fatty acid contents of D. salina Y6 grown under different abiotic-stress conditions, including high light, nitrogen depletion, and high salinity. Results: Both high-salinity and nitrogen-depleted conditions significantly inhibited cell growth. Nitrogen depletion significantly induced β-carotene accumulation, whereas lutein production was promoted by high light. The accumulation of lipids did not directly positive correlate with β-carotene and lutein accumulation under the three tested abiotic-stress conditions, and levels of only a few fatty acids were increased under specific conditions. Conclusion: Our data indicate that cellular β-carotene accumulation in D. salina Y6 positive correlates with accumulation of specific fatty acids (C16:0, C18:3n3, C14:0, and C15:0) rather than with total fatty acid content under different abiotic stress conditions.
Outbreaks of hydropericardium hepatitis syndrome caused by fowl adenovirus serotype 4 (FAdV-4) with a novel genotype have been reported in China since 2015, with significant economic losses to the poultry industry. Fiber2 is one of the important structural proteins on FAdV-4 virions. In this study, the C-terminal knob domain of the FAdV-4 Fiber2 protein was expressed and purified, and its trimer structure (PDB ID: 7W83) was determined for the first time. A series of affinity peptides targeting the knob domain of the Fiber2 protein were designed and synthesized on the basis of the crystal structure using computer virtual screening technology. A total of eight peptides were screened using an immunoperoxidase monolayer assay and RT-qPCR, and they exhibited strong binding affinities to the knob domain of the FAdV-4 Fiber2 protein in a surface plasmon resonance assay. Treatment with peptide number 15 (P15; WWHEKE) at different concentrations (10, 25, and 50 μM) significantly reduced the expression level of the Fiber2 protein and the viral titer during FAdV-4 infection. P15 was found to be an optimal peptide with antiviral activity against FAdV-4 in vitro with no cytotoxic effect on LMH cells up to 200 μM. This study led to the identification of a class of affinity peptides designed using computer virtual screening technology that targeted the knob domain of the FAdV-4 Fiber2 protein and may be developed as a novel potential and effective antiviral strategy in the prevention and control of FAdV-4.
Background Extracellular vesicles (EVs) are nanoparticles with membrane structures secreted by cells that play a role in the transfer of proteins, lipids, small RNAs, lncRNAs and DNA. Thus, EVs mediate mammalian cell-to-cell communication and have potential applications in the diagnosis and treatment of diseases. However, these studies have been primarily focused on the microenvironmental fluids between mammalian cells. Microalgae are single-celled organisms living in natural and dynamic aquatic environments. Whether microalgae can secrete EVs and adapt to changing environments via EV-mediated communication between cells is still unclear. ResultsWe demonstrated that EVs are widely present in microalgae and have surprisingly rich contents of miRNAs and proteins. The differential expression of miRNAs and proteins was correlated with different cell growth stages and abiotic stressors. Our preliminary data suggested that Chlamydomonas EVs significantly affected the growth of the cyanobacterium Synechocystis in full BG11 medium. However, incubating EVs isolated from Chlamydomonas with Synechocystis cells showed that EVs themselves did not promote cell growth in nitrogen depleted BG11 medium. In this case, EVs appear to function primarily via information sensing and message delivery between cells under nutrient stress conditions. More detailed studies need to be conducted to revise our current perspective on the distribution of nutrients in aquatic environments and how EVs may affect microbial communications and interactions.Conculsions These findings suggest that EVs may play a critically important role in information exchange between microalgal cells and, in turn, adaptation to changing aquatic environments.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.