Recent advances of N-α-acetyltransferases in regulating plant growth and development and stress response

LIU Hai-Qing^1,2,* , GONG Lei^1,2

¹Gansu Key Laboratory of Protection and Utilization for Biological Resources and Ecological Restoration, Qingyang 745000, China ²School of Agriculture and Bioengineering, Longdong University, Qingyang 745000, China

Abstract:

N-terminal acetylation (NTA) is an ancient protein modification conserved throughout all kingdoms of life. N-terminally acetylated proteins are present in the cytosol (80%), and the plasma membrane and plastids of plants (20%). The studies have shown this modification can alter key characteristics of proteins such as their threedimensional structure, and affect a variety of physiological and biochemical processes such as protein interaction, subcellular localization, protein folding and polymerization, sorting and stability, etc. The majority of proteins are acetylated by five ribosome-bound N-terminal acetyltransferases (Nats) in yeast, humans and plants, and NTA has been known as an exclusively co-translational process in eukaryotes. The recent characterization of posttranslationally acting plant Nats, which localize to the plasma membrane and the plastids, has challenged this view. These distinctive features of the plant Nats machinery might constitute adaptations to the environment of plants. But its significance is still enigmatic, and little is known about the biological functions of Nats in plants, especially. This review sheds light on the unique role of plant Nats in the development and stress responses as well as their adaptation to function in different cellular compartments, and the prospect of future research work is put forward.

 

Research prospects of synthetic biotechnology in steroid hormone intermediate production

LIU Duo， ZHANG Ying， ZHOU Xiao^*， YUAN Ying-Jin

(Key Laboratory of Systems Bioengineering of Ministry of Education， School of Chemical Engineering and Technology， Tianjin University， Tianjin 300072， China)

Abstract: Abstract: Steroid drugs have become the second one in the world pharmaceutical market， right after the antibiotics. All types of steroid drugs are derived from the steroid hormone intermediates. For the production of steroid hormone intermediates， traditional methods include plant saponin extraction method and total synthesis method. Both of them are detrimental to environment， yield the mixing of different structural products， and too expensive for industrial production. At present， the common method is semi-synthesis which uses certain raw material and microorganisms， while faces the problems such as low enzyme conversion rate and long fermentation period. The advent of synthetic biology provides a theoretical basis and reliable technical support for constructing artificial cells that can synthesize steroid hormone intermediates using sugar as the sole carbon resource. This review summarized the application of synthetic biotechnology in the production of steroid hormone intermediates. Cholesterol，
androstendione and other steroid intermediates can be synthesized by introducing exogenous synthetic function modules， using Saccharomyces cerevisiae and mycobacteria as chassis suitable for industrial fermentation. Furthermore， the application of synthetic biotechnology is also discussed in changing pharmaceutical production mode， expecting to promote the progress of steroid biological pharmaceutical technologies.

 

Research progress on the biosynthesis of aromatic compounds by microorganisms

JIANG Jing-Jie1， LIU Tao2， LIN Shuang-Jun1*

(1 The State Key Laboratory of Microbial Metabolism， School of Life Sciences & Biotechnology， Shanghai Jiao Tong University， Shanghai 200240， China;
2 Tianjin Institute of Industrial Biotechnology， Chinese Academy of Sciences， Tianjin 300308， China)

Abstract: Abstract: Aromatic compounds are an important class of natural products. They are widely distributed in nature and are used in many fields such as food， medicine， and chemical industry. They are mainly obtained by chemical synthesis and plant extraction. In recent years， with the reduction of petrochemical resources and the enhancement of human environmental awareness， microbial synthesis of aromatic compounds and their derivatives has become a hot spot. The aromatic compounds and their derivatives synthesized by the shikimate pathway are diverse. This review focuses on the advances in the microbial synthesis of shikimic acid (the synthetic precursor of oseltamivir)， cis，cis-muconic acid (the precursor of the bulk chemical adipic acid)， aromatic amino acids， and other high value-added aromatic amino acid derivatives synthesized by the shikimate pathway. This review will provide some advice on the establishment of cell factories for the production of high value-added compounds.

 

Research progress on the biosynthesis of aromatic compounds by microorganisms

JIANG Jing-Jie1， LIU Tao2， LIN Shuang-Jun1*

(1 The State Key Laboratory of Microbial Metabolism， School of Life Sciences & Biotechnology， Shanghai Jiao Tong University， Shanghai 200240， China;
2 Tianjin Institute of Industrial Biotechnology， Chinese Academy of Sciences， Tianjin 300308， China)

Abstract: Abstract: Aromatic compounds are an important class of natural products. They are widely distributed in nature and are used in many fields such as food， medicine， and chemical industry. They are mainly obtained by chemical synthesis and plant extraction. In recent years， with the reduction of petrochemical resources and the enhancement of human environmental awareness， microbial synthesis of aromatic compounds and their derivatives has become a hot spot. The aromatic compounds and their derivatives synthesized by the shikimate pathway are diverse. This review focuses on the advances in the microbial synthesis of shikimic acid (the synthetic precursor of oseltamivir)， cis，cis-muconic acid (the precursor of the bulk chemical adipic acid)， aromatic amino acids， and other high value-added aromatic amino acid derivatives synthesized by the shikimate pathway. This review will provide some advice on the establishment of cell factories for the production of high value-added compounds.

 

Equol Effects

Effects
It has been reported that equol has a higher ability to bind to ER (particularly ERβ) than soy isoflavones and has a significantly high transitivity to target organs such as breast and prostate tissues (Non-patent literature 1-4). In addition, case-control studies have reported that patients producing equol are significantly less in patients with breast cancer and prostate cancer. The effects of soy isoflavones on improving bone density and lipid metabolism were examined by dividing postmenopausal women into two groups: women who produce equol and women who do not produce equol. Significant improvements were observed in women who produce equol.
Equol is produced by the metabolism of soy isoflavones by intestinal bacteria. The ability to produce equol varies between individuals, and the percentage of Japanese who produce equol is reported to be about 50%. That is, about 50% of Japanese cannot produce equol (non-equol producing individuals). Such individuals cannot benefit from any favorable physiological effects based on the action of equol even if they consume soybeans and processed soy foods. Therefore, in order to obtain the beneficial physiological effects based on the action of equol in non-equol producing individuals, it is considered that ingestion of equol itself is also effective.
Compared with other polyphenolic compounds, equol is a superior antioxidant, and several in vitro tests have shown that it has stronger antioxidant capacity than vitamin C or vitamin E. Rufer and Kulling et al. found that when six different antioxidants were used for in vitro tests, genistein, daidzein and equol showed higher antioxidant activity, and it was better than the positive control quercetin and ascorbic acid. In addition, Chung et al. proved that equol has a significant antioxidant effect in bovine aortic endothelial cells, and equol can protect cells from hydrogen peroxide-induced cell death. In addition, equol can also protect porcine and human pulmonary artery endothelial cells from apoptosis and vascular damage through oxidative stress.
The antioxidant effect of equol is another important function besides its hormone-like effect. Studies have found that its antioxidant activity is mainly regulated by interaction with ERβ, which induces extracellular signal-regulated protein kinase ERK1/2 and nuclear factor-κB peptide, which control transcription, cytokine production and cell survival. Equol itself is not an antioxidant, but it triggers cell signaling pathways, leading to changes in the expression of cellular enzymes such as superoxide dismutase, catalase, and glutathione peroxidase, causing oxidative stress. It reduces oxidative stress cascade events through various biochemical/molecular actions and mechanisms, achieves antioxidant effects and enhances extracellular matrix, and reduces skin aging.
References
Sun Ao, Tang Rui, Li Wenxuan, Xin Caiyan, Wang Fen. Research status and prospects of antibacterial effects of equol[J]. Frontiers of Microbiology, 2022, 11(4): 191-195.