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Ester-Producing Mechanism of Ethanol O-acyltransferase EHT1 Gene in Pichia pastoris from Shanxi Aged Vinegar. BIOMED RESEARCH INTERNATIONAL 2019; 2019:4862647. [PMID: 30719444 PMCID: PMC6335666 DOI: 10.1155/2019/4862647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 12/07/2018] [Accepted: 12/20/2018] [Indexed: 11/17/2022]
Abstract
The ethanol O-acyltransferase EHT1 is an important element of key signaling pathways and is widely expressed in yeast strains. In this study, we investigated the expression of EHT1 in the overexpression lines or knockout system of Pichia pastoris using qRT-PCR and western blotting. The amount of total protein was determined using the Bradford method; the esterase activity was determined using p-nitrophenyl acetate as a substrate, and the production of volatile fatty acids in wild-type, knockout, and over-expression systems was detected using SPME GC-MS. The esterase activity of EHT1-knockout P. pastoris was significantly lower than that in wild type (P<0.01), and the activities of esterase in three EHT1-overexpressing strains—OE-1, OE-2, and OE-3—were significantly higher than those in wild type (P<0.01). In the EHT1-knockout strain products, the contents of nine volatile fatty acids were significantly lower than those in wild type (P<0.01), and the relative percentages of three fatty acids, methyl nonanoate, methyl decanoate, and ethyl caprate, were significantly lower than those in the other six species in the wild-type and knockout groups (P<0.05). The nine volatile fatty acids in the fermentation products of the overexpressed EHT1 gene were significantly higher than those in the wild-type group (P<0.01). The relative percentages of the three fatty acid esters, methyl nonanoate, methyl caprate, and ethyl caprate, were significantly higher than those in the other six species (P<0.05). EHT1 plays an important regulatory role in esterase activity and the production of medium-chain volatile fatty acids.
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Klages-Mundt NL, Kumar A, Zhang Y, Kapoor P, Shen X. The Nature of Actin-Family Proteins in Chromatin-Modifying Complexes. Front Genet 2018; 9:398. [PMID: 30319687 PMCID: PMC6167448 DOI: 10.3389/fgene.2018.00398] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 08/31/2018] [Indexed: 01/25/2023] Open
Abstract
Actin is not only one of the most abundant proteins in eukaryotic cells, but also one of the most versatile. In addition to its familiar involvement in enabling contraction and establishing cellular motility and scaffolding in the cytosol, actin has well-documented roles in a variety of processes within the confines of the nucleus, such as transcriptional regulation and DNA repair. Interestingly, monomeric actin as well as actin-related proteins (Arps) are found as stoichiometric subunits of a variety of chromatin remodeling complexes and histone acetyltransferases, raising the question of precisely what roles they serve in these contexts. Actin and Arps are present in unique combinations in chromatin modifiers, helping to establish structural integrity of the complex and enabling a wide range of functions, such as recruiting the complex to nucleosomes to facilitate chromatin remodeling and promoting ATPase activity of the catalytic subunit. Actin and Arps are also thought to help modulate chromatin dynamics and maintain higher-order chromatin structure. Moreover, the presence of actin and Arps in several chromatin modifiers is necessary for promoting genomic integrity and an effective DNA damage response. In this review, we discuss the involvement of actin and Arps in these nuclear complexes that control chromatin remodeling and histone modifications, while also considering avenues for future study to further shed light on their functional importance.
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Affiliation(s)
- Naeh L Klages-Mundt
- Science Park Research Division, Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX, United States.,Program in Genetics & Epigenetics, The University of Texas MD Anderson Cancer Center, UTHealth Graduate School of Biomedical Sciences, Houston, TX, United States
| | - Ashok Kumar
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, TX, United States
| | - Yuexuan Zhang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Prabodh Kapoor
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, TX, United States
| | - Xuetong Shen
- Science Park Research Division, Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX, United States.,Program in Genetics & Epigenetics, The University of Texas MD Anderson Cancer Center, UTHealth Graduate School of Biomedical Sciences, Houston, TX, United States
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Hooykaas PJJ, van Heusden GPH, Niu X, Reza Roushan M, Soltani J, Zhang X, van der Zaal BJ. Agrobacterium-Mediated Transformation of Yeast and Fungi. Curr Top Microbiol Immunol 2018; 418:349-374. [PMID: 29770864 DOI: 10.1007/82_2018_90] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Two decades ago, it was discovered that the well-known plant vector Agrobacterium tumefaciens can also transform yeasts and fungi when these microorganisms are co-cultivated on a solid substrate in the presence of a phenolic inducer such as acetosyringone. It is important that the medium has a low pH (5-6) and that the temperature is kept at room temperature (20-25 °C) during co-cultivation. Nowadays, Agrobacterium-mediated transformation (AMT) is the method of choice for the transformation of many fungal species; as the method is simple, the transformation efficiencies are much higher than with other methods, and AMT leads to single-copy integration much more frequently than do other methods. Integration of T-DNA in fungi occurs by non-homologous end-joining (NHEJ), but also targeted integration of the T-DNA by homologous recombination (HR) is possible. In contrast to AMT of plants, which relies on the assistance of a number of translocated virulence (effector) proteins, none of these (VirE2, VirE3, VirD5, VirF) are necessary for AMT of yeast or fungi. This is in line with the idea that some of these proteins help to overcome plant defense. Importantly, it also showed that VirE2 is not necessary for the transport of the T-strand into the nucleus. The yeast Saccharomyces cerevisiae is a fast-growing organism with a relatively simple genome with reduced genetic redundancy. This yeast species has therefore been used to unravel basic molecular processes in eukaryotic cells as well as to elucidate the function of virulence factors of pathogenic microorganisms acting in plants or animals. Translocation of Agrobacterium virulence proteins into yeast was recently visualized in real time by confocal microscopy. In addition, the yeast 2-hybrid system, one of many tools that have been developed for use in this yeast, was used to identify plant and yeast proteins interacting with the translocated Agrobacterium virulence proteins. Dedicated mutant libraries, containing for each gene a mutant with a precise deletion, have been used to unravel the mode of action of some of the Agrobacterium virulence proteins. Yeast deletion mutant collections were also helpful in identifying host factors promoting or inhibiting AMT, including factors involved in T-DNA integration. Thus, the homologous recombination (HR) factor Rad52 was found to be essential for targeted integration of T-DNA by HR in yeast. Proteins mediating double-strand break (DSB) repair by end-joining (Ku70, Ku80, Lig4) turned out to be essential for non-homologous integration. Inactivation of any one of the genes encoding these end-joining factors in other yeasts and fungi was employed to reduce or totally eliminate non-homologous integration and promote efficient targeted integration at the homologous locus by HR. In plants, however, their inactivation did not prevent non-homologous integration, indicating that T-DNA is captured by different DNA repair pathways in plants and fungi.
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Affiliation(s)
- Paul J J Hooykaas
- Sylvius Lab, Department of Molecular and Developmental Genetics, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands.
| | - G Paul H van Heusden
- Sylvius Lab, Department of Molecular and Developmental Genetics, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
| | - Xiaolei Niu
- Sylvius Lab, Department of Molecular and Developmental Genetics, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
| | - M Reza Roushan
- Sylvius Lab, Department of Molecular and Developmental Genetics, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
| | - Jalal Soltani
- Sylvius Lab, Department of Molecular and Developmental Genetics, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
| | - Xiaorong Zhang
- Sylvius Lab, Department of Molecular and Developmental Genetics, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
| | - Bert J van der Zaal
- Sylvius Lab, Department of Molecular and Developmental Genetics, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
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Idnurm A, Bailey AM, Cairns TC, Elliott CE, Foster GD, Ianiri G, Jeon J. A silver bullet in a golden age of functional genomics: the impact of Agrobacterium-mediated transformation of fungi. Fungal Biol Biotechnol 2017; 4:6. [PMID: 28955474 PMCID: PMC5615635 DOI: 10.1186/s40694-017-0035-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 09/18/2017] [Indexed: 11/10/2022] Open
Abstract
The implementation of Agrobacterium tumefaciens as a transformation tool revolutionized approaches to discover and understand gene functions in a large number of fungal species. A. tumefaciens mediated transformation (AtMT) is one of the most transformative technologies for research on fungi developed in the last 20 years, a development arguably only surpassed by the impact of genomics. AtMT has been widely applied in forward genetics, whereby generation of strain libraries using random T-DNA insertional mutagenesis, combined with phenotypic screening, has enabled the genetic basis of many processes to be elucidated. Alternatively, AtMT has been fundamental for reverse genetics, where mutant isolates are generated with targeted gene deletions or disruptions, enabling gene functional roles to be determined. When combined with concomitant advances in genomics, both forward and reverse approaches using AtMT have enabled complex fungal phenotypes to be dissected at the molecular and genetic level. Additionally, in several cases AtMT has paved the way for the development of new species to act as models for specific areas of fungal biology, particularly in plant pathogenic ascomycetes and in a number of basidiomycete species. Despite its impact, the implementation of AtMT has been uneven in the fungi. This review provides insight into the dynamics of expansion of new research tools into a large research community and across multiple organisms. As such, AtMT in the fungi, beyond the demonstrated and continuing power for gene discovery and as a facile transformation tool, provides a model to understand how other technologies that are just being pioneered, e.g. CRISPR/Cas, may play roles in fungi and other eukaryotic species.
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Affiliation(s)
- Alexander Idnurm
- School of BioSciences, University of Melbourne, Melbourne, VIC 3010 Australia
| | - Andy M. Bailey
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Timothy C. Cairns
- Department of Applied and Molecular Microbiology, Technische Universität Berlin, Berlin, Germany
| | - Candace E. Elliott
- School of BioSciences, University of Melbourne, Melbourne, VIC 3010 Australia
| | - Gary D. Foster
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Giuseppe Ianiri
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, USA
| | - Junhyun Jeon
- College of Life and Applied Sciences, Yeungnam University, Gyeongsan, South Korea
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Targeted Inhibition of the miR-199a/214 Cluster by CRISPR Interference Augments the Tumor Tropism of Human Induced Pluripotent Stem Cell-Derived Neural Stem Cells under Hypoxic Condition. Stem Cells Int 2016; 2016:3598542. [PMID: 27965712 PMCID: PMC5124688 DOI: 10.1155/2016/3598542] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 10/15/2016] [Accepted: 10/25/2016] [Indexed: 12/30/2022] Open
Abstract
The human induced pluripotent stem cell (hiPSC) provides a breakthrough approach that helps overcoming ethical and allergenic challenges posed in application of neural stem cells (NSCs) in targeted cancer gene therapy. However, the tumor-tropic capacity of hiPSC-derived NSCs (hiPS-NSCs) still has much room to improve. Here we attempted to promote the tumor tropism of hiPS-NSCs by manipulating the activity of endogenous miR-199a/214 cluster that is involved in regulation of hypoxia-stimulated cell migration. We first developed a baculovirus-delivered CRISPR interference (CRISPRi) system that sterically blocked the E-box element in the promoter of the miR-199a/214 cluster with an RNA-guided catalytically dead Cas9 (dCas9). We then applied this CRISPRi system to hiPS-NSCs and successfully suppressed the expression of miR-199a-5p, miR-199a-3p, and miR-214 in the microRNA gene cluster. Meanwhile, the expression levels of their targets related to regulation of hypoxia-stimulated cell migration, such as HIF1A, MET, and MAPK1, were upregulated. Further migration assays demonstrated that the targeted inhibition of the miR-199a/214 cluster significantly enhanced the tumor tropism of hiPS-NSCs both in vitro and in vivo. These findings suggest a novel application of CRISPRi in NSC-based tumor-targeted gene therapy.
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