The role of phenylalanine hydroxylase in lipogenesis in the oleaginous fungus Mortierella alpina

Microbiology ◽  
2021 ◽  
Vol 167 (8) ◽  
Author(s):  
Hongchao Wang ◽  
Chunmei Wang ◽  
Weiwei Yuan ◽  
Haiqin Chen ◽  
Wenwei Lu ◽  
...  

Phenylalanine hydroxylase (PAH) catalyses the irreversible hydroxylation of phenylalanine to tyrosine, which is the rate-limiting reaction in phenylalanine metabolism in animals. A variety of polyunsaturated fatty acids can be synthesized by the lipid-producing fungus Mortierella alpina, which has a wide range of industrial applications in the production of arachidonic acid. In this study, RNA interference (RNAi) with the gene PAH was used to explore the role of phenylalanine hydroxylation in lipid biosynthesis in M. alpina. Our results indicated that PAH knockdown decreased the PAH transcript level by approximately 55% and attenuated cellular fatty acid biosynthesis. Furthermore, the level of NADPH, which is a critical reducing agent and the limiting factor in lipogenesis, was decreased in response to PAH RNAi, in addition to the downregulated transcription of other genes involved in NADPH production. Our study indicates that PAH is part of an overall enzymatic and regulatory mechanism supplying NADPH required for lipogenesis in M. alpina.


Microbiology ◽  
2020 ◽  
Vol 166 (7) ◽  
pp. 617-623
Author(s):  
Hongchao Wang ◽  
Qizai Wang ◽  
Chen Zhang ◽  
Haiqin Chen ◽  
Wenwei Lu ◽  
...  

The oleaginous fungus Mortierella alpina can synthesize a variety of polyunsaturated fatty acids, which are used extensively in industry for the production of arachidonic acid (AA). NADPH is the limiting factor and critical reducing agent in lipid biosynthesis. In the folate cycle, methylenetetrahydrofolate dehydrogenase (MTHFDL) catalyzes the conversion of methylene tetrahydrofolate into 10-formyl-tetrahydrofolate with the reduction of NADP+ to NADPH. MTHFDL RNAi was used to investigate the role of the folate cycle in lipogenesis. Gene knockdown decreased the transcript levels of MTHFDL by about 50 % and attenuated cell fatty acid synthesis. The observation of decreased NADPH levels and downregulated NADPH-producing genes in response to MTHFDL RNAi indicates a novel aspect of the NADPH regulatory mechanism. Thus, our study demonstrates that MTHFDL plays key role in the mediation of NADPH in lipogenesis in M. alpina.



Author(s):  
Fengzhu Ling ◽  
Xin Tang ◽  
Hao Zhang ◽  
Yong Q. Chen ◽  
Jianxin Zhao ◽  
...  


2014 ◽  
Vol 80 (9) ◽  
pp. 2672-2678 ◽  
Author(s):  
G. Hao ◽  
H. Chen ◽  
L. Wang ◽  
Z. Gu ◽  
Y. Song ◽  
...  


2018 ◽  
Vol 45 (4) ◽  
pp. 281-291 ◽  
Author(s):  
Jing Guo ◽  
Haiqin Chen ◽  
Bo Yang ◽  
Hao Zhang ◽  
Wei Chen ◽  
...  


2005 ◽  
Vol 77 (9) ◽  
pp. iv ◽  
Author(s):  
Kenneth Kustin ◽  
Tamas Kiss

The following 10 papers are selections from the 4th International Symposium on Chemistry and Biological Chemistry of Vanadium held 3-5 September 2004 in Szeged, Hungary. This conference attracted over 110 participants from 25 countries and 4 continents. Plenary and invited lectures as well as posters discussed the inorganic chemistry of vanadium, vanadium chemistry in catalysis and organic synthesis, and biological aspects of vanadium chemistry. A new feature was introduced: the presentation of the Vanadis Award.The purpose of the Vanadis Award is to recognize an outstanding contributor to the advancement of vanadium science. The award will be presented at each International Vanadium Symposium prior to a lecture to be given by the recipient. It is awarded on the basis of contributions to a discipline or combination of disciplines of vanadium science, and is presented to an investigator who has produced innovative research with impact on the direction of the field. The nominee is selected on the basis of the following criteria: (1) Innovative research: A history of development or expansion of techniques and procedures and discovery of new chemical, biochemical, biological, technological, or pharmaceutical systems; (2) Development of new applications in one or more of the following areas: chemistry, biochemistry, biology, pharmaceutical science, materials science, and nanotechnology; (3) Wide-ranging influence of the nominee's work on the research of others in one or more disciplines; (4) History of highquality and -impact publications; and (5) Service of the nominee to progress, application, and exploration of vanadium in science. The recipient of the first Vanadis Award is Prof. Debbie C. Crans of Colorado State University, whose award address is the first contribution to be presented herein.The additional contributions begin with papers covering various aspects of the inorganic chemistry of vanadium. These papers are followed by descriptions of recent results in the use of vanadium compounds to further organic synthesis, and on the catalytic behavior of interesting vanadium complexes. The final selection includes papers dealing with the role of vanadium in haloperoxidases, or as insulin-mimetic compounds, which may be orally administered replacements of insulin injections.A tremendous increase in studies of aqueous vanadium chemistry over the past decade has been driven by the need to comprehend the diverse biological effects of vanadium. Examples of the rich array of data and concepts needed to explain the biological role of vanadium are given by models of the vanadium-containing haloperoxidase enzyme activity. However, this selection of papers from the 4th International Vanadium Symposium indicates that basic inorganic studies and a wide range of applications of vanadium chemistry to fundamental chemical problems of synthesis, reactivity, and catalysis are not lacking. Indeed, we look forward to the 5th International Vanadium Symposium to be held in San Francisco, CA USA in the fall of 2006, where additional fundamental studies linked to the need to better understand vanadium nutritional essentiality, vanadium toxicity, vanadium therapy, and vanadium catalysis, including "green chemical" industrial applications will be presented.Kenneth Kustin and Tamas KissConference Editors



Microbiology ◽  
2016 ◽  
Vol 162 (9) ◽  
pp. 1544-1553 ◽  
Author(s):  
Hongchao Wang ◽  
Chen Zhang ◽  
Jinghan Feng ◽  
Yuan Liu ◽  
Qin Yang ◽  
...  


Plants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 397
Author(s):  
Huong Thi Diem Tran ◽  
Nhan Trong Le ◽  
Vy Le Uyen Khuat ◽  
Thuong Thi Hong Nguyen

(1) Background: Plants possess many acyl-acyl carrier protein (acyl-ACP) thioesterases (TEs) with unique specificity. One such TE is methylketone synthase 2 (MKS2), an enzyme with a single-hotdog-fold structure found in several tomato species that hydrolyzes 3-ketoacyl-ACPs to give free 3-ketoacids. (2) Methods: In this study, we identified and characterized a tomato MKS2 homolog gene, namely, GmMKS2, in the genome of soybean (Glycine max). (3) Results: GmMKS2 underwent alternative splicing to produce three alternative transcripts, but only one encodes a protein with thioesterase activity when recombinantly expressed in Escherichia coli. Heterologous expression of the main transcript of GmMKS2, GmMKS2-X2, in E. coli generated various types of fatty acids, including 3-ketoacids—with 3-ketotetradecenoic acid (14:1) being the most abundant—cis-Δ5-dodecanoic acid, and 3-hydroxyacids, suggesting that GmMKS2 acts as an acyl-ACP thioesterase. In plants, the GmMKS2-X2 transcript level was found to be higher in the roots compared to other examined organs. In silico analysis revealed that there is a substantial enrichment of putative cis-regulatory elements related to disease-resistance responses and abiotic stress responses in the promoter of this gene. (4) Conclusions: GmMKS2 showed broad substrate specificities toward a wide range of acyl-ACPs that varied in terms of chain length, oxidation state, and saturation degree. Our results suggest that GmMKS2 might have a stress-related physiological function in G. max.



2019 ◽  
Vol 67 (34) ◽  
pp. 9551-9559 ◽  
Author(s):  
Lulu Chang ◽  
Xin Tang ◽  
Hengqian Lu ◽  
Hao Zhang ◽  
Yong Q. Chen ◽  
...  


Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 912 ◽  
Author(s):  
Gerald Singer ◽  
Philipp Siedlaczek ◽  
Gerhard Sinn ◽  
Harald Rennhofer ◽  
Matej Mičušík ◽  
...  

Carbon nanotubes (CNT) provide an outstanding property spectrum which can be used to improve a wide range of materials. However, the transfer of properties from the nanoscale to a macroscopic material is a limiting factor. Different approaches of functionalizing the surface of a CNT can improve the interaction with the surrounding matrix but is connected to difficult and expensive treatments, which are usually inconvenient for industrial applications. Here, a simple and eco-friendly method is presented for the oxidation of CNT, where hydrogen peroxide (H2O2) is the only chemical needed and no toxic emissions are released. Also, the extensive step of the incorporation of CNT to an epoxy matrix is simplified to an ultrasonic dispersion in the liquid hardener component. The effectiveness is proven by mechanical tests of produced CNT/CFRP and compared to a conventional processing route. The combination of those simple and cost efficient strategies can be utilized to produce multiscale composites with improved mechanical performance in an ecological and economical way.



Sign in / Sign up

Export Citation Format

Share Document