the second and third positions (X-Pro-Pro) in their N-terminal region 8,10. The proline in the N-terminal structure is known to confer resistance to aminopeptidase digestion 16. In the C-terminal region, GLWamides generally possess glycine-leucine-tryptophan (a GLW motif), and the tryptophan residue in the C-terminus is amidated (-Gly-Leu-Trp-NH 2). Scleractinians, also known as stony corals, are ecologically and economically important marine organisms 17. However, only a few studies on GLWamides have been reported to date. Treatment of planula larvae with a GLWamide peptide (Hym-248, EPLPIGLWamide, identified in Hydra) has been shown to induce metamorphosis in specific coral families, such as Acroporidae 18,19. Although the detailed action mechanisms underlying the induction of metamorphosis have not yet been clarified, GLWamides have been suggested to be involved in the developmental control of embryos in corals 18-20. Recently, the sequence of GLWamide preprohormone was reported for the first time in Acropora millepora, and its transcript expression pattern during embryonic development was clearly elucidated by in situ hybridization 21. In adult A. millepora, although the transcript expression of GLWamide preprohormone was detected by transcriptome analysis 22 , the spatial distribution of GLWamide neurons and its physiological function remain unknown. The present study attempts to investigate the existence and role of GLWamide neurons in adult corals using the gonochoric stony coral Euphyllia ancora as the main experimental animal. This animal has large polyps, which allows us not only to easily observe the changes in the behavioral characteristics of the polyp but also to isolate different parts of polyp tissues. These attributes enable us to investigate the spatial distribution pattern of target transcripts and proteins within the polyp 23 , which also enables us to perform a bioassay to investigate the effects of the target molecules on specific coral tissues. With these advantages, the present study investigated the possible physiological role of GLWamide by examining the spatial distribution patterns of transcripts of GLWamide preprohormone and GLWamide neurons in adult E. ancora polyps, and the effects of synthetic GLWamides on isolated tissues and whole polyps were also studied. Additionally, the distribution of GLWamide neurons was also investigated in 5 other scleractinian species. Materials and Methods Experimental animals. Specimens of E. ancora were collected at Nanwan Bay in southern Taiwan (21°57′N, 120°46′E) by scuba diving. The collected corals were maintained until use in a 90 L aquarium at National Taiwan Ocean University (NTOU) on a light cycle of approximately 12.5hL: 11.5hD at 26-28 °C. The collection of E. ancora was permitted by the administration office of Kenting National Park (Issue number: 1010006545). Samplings of Stylophora pistillata, Pocillopora damicornis, Acropora hyacinthus, and Favites pentagona were conducted by snorkeling at Pitouchiao Park (25°07′N, 120°54′E) near norther...
BACKGROUND Nicotinamide mononucleotide (NMN), a key intermediate of nicotinamide adenine dinucleotide, plays an important in anti‐aging and disease. Lactococcus lactis, an important probiotic lactic acid bacteria (LAB), has shown great potential for the biosynthesis of NMN, which will significantly affect the probiotic effects of the dairy products. RESULTS We used the CRISPR/nCas9 technique to knockout nadR gene of L. lactis NZ9000 to enhance the accumulation of NMN by 61%. The nadE* gene from Francisella tularensis with codon optimization was heterologous in L. lactis NZ9000ΔnadR and has a positive effect on NMN production. Combined with optimization of the concentration of substrate nicotinamide, a final intracellular NMN titer was 2289 μmol L–1 mg–1 with 10 g L–1 nicotinamide supplement, which was 5.7‐fold higher than that of the control. The transcription levels of key genes (pncA, nadD and prs1) involved in NMN biosynthesis were up‐regulated by more than two‐fold, indicating that the increase of NMN titer was attributed to FtnadE* heterologous expression. CONCLUSION Our study provides a better understanding of the NMN biosynthesis pathway in L. lactis, and can facilitate NMN production in LAB via synthetic biology approaches. © 2022 Society of Chemical Industry.
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.