Journal of Microbiology

Review

Host–microbial interactions in metabolic diseases: from diet to immunity: Ju-Hyung Lee , Joo-Hong Park; J. Microbiol. 2022;60(6):561-575. Published online May 5, 2022; DOI: https://doi.org/10.1007/s12275-022-2087-y

Abstract: Growing evidence suggests that the gut microbiome is an important contributor to metabolic diseases. Alterations in microbial communities are associated with changes in lipid metabolism, glucose homeostasis, intestinal barrier functions, and chronic inflammation, all of which can lead to metabolic disorders. Therefore, the gut microbiome may represent a novel therapeutic target for obesity, type 2 diabetes, and nonalcoholic fatty liver disease. This review discusses how gut microbes and their products affect metabolic diseases and outlines potential treatment approaches via manipulation of the gut microbiome. Increasing our understanding of the interactions between the gut microbiome and host metabolism may help restore the healthy symbiotic relationship between them.

Journal Articles

The velvet repressed vidA gene plays a key role in governing development in Aspergillus nidulans: Min-Ju Kim , Won-Hee Jung , Ye-Eun Son , Jae-Hyuk Yu , Mi-Kyung Lee , Hee-Soo Park; J. Microbiol. 2019;57(10):893-899. Published online August 28, 2019; DOI: https://doi.org/10.1007/s12275-019-9214-4

Abstract: Fungal development is regulated by a variety of transcription factors in Aspergillus nidulans. Previous studies demonstrated that the NF-κB type velvet transcription factors regulate certain target genes that govern fungal differentiation and cellular metabolism. In this study, we characterize one of the VosA/VelB-inhibited developmental genes called vidA, which is predicted to encode a 581-amino acid protein with a C2H2 zinc finger domain at the C-terminus. Levels of vidA mRNA are high during the early and middle phases of asexual development and decrease during the late phase of asexual development and asexual spore (conidium) formation. Deletion of either vosA or velB results in increased vidA mRNA accumulation in conidia, suggesting that vidA transcript accumulation in conidia is repressed by VosA and VelB. Phenotypic analysis demonstrated that deletion of vidA causes decreased colony growth, reduced production of asexual spores, and abnormal formation of sexual fruiting bodies. In addition, the vidA deletion mutant conidia contain more trehalose and β-glucan than wild type. Overall, these results suggest that VidA is a putative transcription factor that plays a key role in governing proper fungal growth, asexual and sexual development, and conidia formation in A. nidulans.

Characterization of the velvet regulators in Aspergillus flavus: Tae-Jin Eom , Heungyun Moon , Jae-Hyuk Yu , Hee-Soo Park; J. Microbiol. 2018;56(12):893-901. Published online October 25, 2018; DOI: https://doi.org/10.1007/s12275-018-8417-4

Abstract: Fungal development and secondary metabolism are closely associated via the activities of the fungal NK-kB-type velvet regulators that are highly conserved in filamentous fungi. Here, we investigated the roles of the velvet genes in the aflatoxigenic fungus Aspergillus flavus. Distinct from other Aspergillus species, the A. flavus genome contains five velvet genes, veA, velB, velC, velD, and vosA. The deletion of velD blocks the production of aflatoxin B1, but does not affect the formation of sclerotia. Expression analyses revealed that vosA and velB mRNAs accumulated at high levels during the late phase of asexual development and in conidia. The absence of vosA or velB decreased the content of conidial trehalose and the tolerance of conidia to the thermal and UV stresses. In addition, double mutant analyses demonstrated that VosA and VelB play an inter-dependent role in trehalose biosynthesis and conidial stress tolerance. Together with the findings of previous studies, the results of the present study suggest that the velvet regulators play the conserved and vital role in sporogenesis, conidial trehalose biogenesis, stress tolerance, and aflatoxin biosynthesis in A. flavus.

Review

REVIEW] Transcriptional Regulatory Elements in Fungal Secondary Metabolism: Wenbing Yin , Nancy P. Keller; J. Microbiol. 2011;49(3):329-339. Published online June 30, 2011; DOI: https://doi.org/10.1007/s12275-011-1009-1

Abstract: Filamentous fungi produce a variety of secondary metabolites of diverse beneficial and detrimental activities to humankind. The genes required for a given secondary metabolite are typically arranged in a gene cluster. There is considerable evidence that secondary metabolite gene regulation is, in part, by transcriptional control through hierarchical levels of transcriptional regulatory elements involved in secondary metabolite cluster regulation. Identification of elements regulating secondary metabolism could potentially provide a means of increasing production of beneficial metabolites, decreasing production of detrimental metabolites, aid in the identification of ‘silent’ natural products and also contribute to a broader understanding of molecular mechanisms by which secondary metabolites are produced. This review summarizes regulation of secondary metabolism associated with transcriptional regulatory elements from a broad view as well as the tremendous advances in discovery of cryptic or novel secondary metabolites by genomic mining.

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