• Journal of Microbiology and Biotechnology
• /
• 제20권3호
• /
• pp.480-484
• /
• 2010

AfsR2 is a global regulatory protein that stimulates antibiotic biosynthesis in both Streptomyces lividans and S. coelicolor. Previously, various afsR2-dependent genes including a putative abaA-like regulatory gene, SCO4677, were identified through comparative DNA microarray analysis. To further identify the putative SCO4677-dependent proteins, the comparative proteomics-driven approach was applied to the SCO4677-overexpressing strains of S. lividans and S. coelicolor along with the wild-type strains. The 2D gel electrophoresis gave approximately 277 protein spots for S. lividans and 207 protein spots for S. coelicolor, showing different protein expression patterns between the SCO4677-overexpressing strains and the wild-type strains. Further MALDI-TOF analysis revealed that only 18 proteins exhibited similar expression patterns in both S. lividans and S. coelicolor, suggesting that the SCO4677 could encode an abaA-like regulator that controls a few cross-species common proteins as well as many species-specific proteins in Streptomyces species.

• Journal of Microbiology and Biotechnology
• /
• 제31권8호
• /
• pp.1154-1162
• /
• 2021

The transcriptional capacities of target genes are strongly influenced by promoters, whereas few studies have focused on the development of robust, high-performance and cross-species promoters for wide application in different bacteria. In this work, four novel promoters (P_k.rtufB, P_k.r1, P_k.r2, and P_k.r3) were predicted from Ketogulonicigenium robustum and their inconsistency in the -10 and -35 region nucleotide sequences indicated they were different promoters. Their activities were evaluated by using green fluorescent protein (gfp) as a reporter in different species of bacteria, including K. vulgare SPU B805, Pseudomonas putida KT2440, Paracoccus denitrificans PD1222, Bacillus licheniformis and Raoultella ornithinolytica, due to their importance in metabolic engineering. Our results showed that the four promoters had different activities, with P_k.r1 showing the strongest activity in almost all of the experimental bacteria. By comparison with the commonly used promoters of E. coli (tufB, lac, lacUV5), K. vulgare (Psdh, Psndh) and P. putida KT2440 (JE111411), the four promoters showed significant differences due to only 12.62% nucleotide similarities, and relatively higher ability in regulating target gene expression. Further validation experiments confirmed their ability in initiating the target minCD cassette because of the shape changes under the promoter regulation. The overexpression of sorbose dehydrogenase and cytochrome c551 by P_k.r1 and P_k.r2 resulted in a 22.75% enhancement of 2-KGA yield, indicating their potential for practical application in metabolic engineering. This study demonstrates an example of applying bioinformatics to find new biological components for gene operation and provides four novel promoters with broad suitability, which enriches the usable range of promoters to realize accurate regulation in different genetic backgrounds.

• 한국미생물·생명공학회지
• /
• 제47권4호
• /
• pp.473-486
• /
• 2019

In the aquatic environment, microorganisms are predominantly organized as biofilms. Biofilms are formed by the aggregation of microbial cells and are surrounded by a matrix of extracellular polymeric substances (EPS) secreted by the microbial cells. Biofilms are attached to various surfaces, such as the living tissues, indwelling medical devices, and piping of the industrial potable water system. Biofilms formed from a single species has been extensively studied. However, there is an increased research focus on multispecies biofilms in recent years. It is important to assess the microbial mechanisms underlying the regulation of multispecies biofilm formation to determine the drinking water microbial composition. These mechanisms contribute to the predominance of the best-adapted species in an aquatic environment. This review focuses on the interactions in the multispecies biofilms, such as coaggregation, co-metabolism, cross-species protection, jamming of quorum sensing, lateral gene transfer, synergism, and antagonism. Further, this review explores the dynamics and the factors favoring biofilm formation and pathogen transmission within the drinking water distribution systems. The understanding of the physiology and biodiversity of microbial species in the biofilm may aid in the development of novel biofilm control and drinking water disinfection processes.

• IMMUNE NETWORK
• /
• 제23권5호
• /
• pp.36.1-36.16
• /
• 2023

Thymic epithelial cells (TECs) play a critical role in thymic development and thymopoiesis. As individuals age, TECs undergo various changes that impact their functions, leading to a reduction in cell numbers and impaired thymic selection. These age-related alterations have been observed in both mice and humans. However, the precise mechanisms underlying age-related TEC dysfunction remain unclear. Furthermore, there is a lack of a comprehensive study that connects mouse and human biological processes in this area. To address this gap, we conducted an extensive transcriptome analysis of young and old TECs in mice, complemented by further analysis of publicly available human TEC single-cell RNA sequencing data. Our analysis revealed alterations in both known and unknown pathways that potentially contribute to age-related TEC dysfunction. Specifically, we observed downregulation of pathways related to cell proliferation, T cell development, metabolism, and cytokine signaling in old age TECs. Conversely, TGF-β, BMP, and Wnt signaling pathways were upregulated, which have been known to be associated with age-related TEC dysfunctions or newly discovered in this study. Importantly, we found that these age-related changes in mouse TECs were consistently present in human TECs as well. This cross-species validation further strengthens the significance of our findings. In conclusion, our comprehensive analysis provides valuable insight into the biological and immunological characteristics of aged TECs in both mice and humans. These findings contribute to a better understanding of thymic involution and age-induced immune dysfunction.

• Journal of Microbiology and Biotechnology
• /
• 제26권1호
• /
• pp.66-71
• /
• 2016

PikD is a widely known pathway-specific regulator for controlling pikromycin production in Streptomyces venezuelae ATCC 15439, which is a representative of the large ATP-binding regulator of the LuxR family (LAL) in Streptomyces sp. RapH and FkbN also belong to the LAL family of transcriptional regulators, which show greatest homology with the ATP-binding motif and helix-turn-helix DNA-binding motif of PikD. Overexpression of pikD and heterologous expression of rapH and fkbN led to enhanced production of pikromycin by approximately 1.8-, 1.6-, and 1.6-fold in S. venezuelae, respectively. Cross-complementation of rapH and fkbN in the pikD deletion mutant (ΔpikD) restored pikromycin and derived macrolactone production. Overall, these results show that heterologous expression of rapH and fkbN leads to the overproduction of pikromycin and its congeners from the pikromycin biosynthetic pathway in S. venezuelae, and they have the same functionality as the pathwayspecific transcriptional activator for the pikromycin biosynthetic pathway in the ΔpikD strain. These results also show extensive "cross-communication" between pathway-specific regulators of streptomycetes and suggest revision of the current paradigm for pathwayspecific versus global regulation of secondary metabolism in Streptomyces species.

• BMB Reports
• /
• 제39권5호
• /
• pp.511-515
• /
• 2006

Alanine aminotransferase (AAT) is mainly synthesized in the liver, and its level in mammalian serum is elevated after acute phase induction. Here we demonstrated that sheep anti-human AAT antibody cross-reacted with amphioxus humoral fluids as well as human serum; and the concentration of AAT in the humoral fluids in amphioxus increased after the acute challenge with lipopolysaccharide, while the level of total proteins remains unchanged. These suggest the presence of the same acute phase response pattern in amphioxus, as observed in some mammalian species. Immunohistochemically, AAT was localized in the hepatic diverticulum, ovary and testis. It appears that the hepatic diverticulum in amphioxus is functionally homologous to the vertebrate liver in respect of AAT synthesis, supporting the hypothesis that the vertebrate liver evolved from the hepatic diverticulum of an amphioxus-like ancestor during early chordate evolution.

• 생명과학회지
• /
• 제19권5호
• /
• pp.587-592
• /
• 2009

임신초기의 배아는 peri-implantation 단계에서 매우 극적인 형태학적변화가 일어나는데, 이는 임신 인식 인자로 작용하는 배아에서 제공된 signal(s)에 의해서 시작되어지며, 나아가서 모성자궁과 배아의 상호 신호전달이 임신의 시작과 유지에 필수적인 인자로 작용한다. 배아형태의 급격한 리모델링에 관련된 세포학적, 생화학적, 유전학적 연구를 위하여, 또한 자궁과 배아의 상호 신호전달에 관여하는 잠재적 유전자 군을 발굴하기 위하여, peri-implantation 시기의 돼지배아를 이용하여 expresses sequences tag (EST) 분석을 실행하였다. 돼지배아 EST 분석으로 임신초기 특히 전 착상 단계에서 발현되는 유전자들의 카탈로그(Transcriptome)를 작성하였다. 그중에서 6개의 clone을 선택하여 그 발현 양식을 배아 및 자궁 등에서 관찰한 결과, 각각의 유전자들은 조직, 세포 유형 및 임신 시기에 따른 특이적인 발현 현상을 나타내었다. 본 연구결과는, 배아와 자궁 내막에서의 유전자 발현이 임신 시기에 따라서 다이내믹한 상호 조절 작용을 하고 있음을 나타낸다. 이는 전 착상단계의 모성자궁에서 배아와 자궁 내막의 상호 신호전달이 전 착상 단계의 배아의 급격한 형태학적 변화를 가능하게하고 또한 착상에 필요한 적절한 자궁 내부 환경을 제공하고 있음을 보여준다.