Molecular regulation of penicillin biosynthesis in Aspergillus (Emericella) nidulans

Background: Lignocellulosic residues generated by various anthropogenic activities can be a potential raw material for many commercial products such as biofuels, organic acids and nutraceuticals including xylitol. Xylitol is a low-calorie nutritive sweetener for diabetic patients. Microbial production of xylitol can be helpful in overcoming the drawbacks of traditional chemical production process and lowring cost of production. Objective: Designing efficient production process needs the characterization of required enzyme/s. Hence current work was focused on in-vitro and in-silico characterization of xylose reductase from Emericella nidulans. Methods: Xylose reductase from one of the hyper-producer isolates, Emericella nidulans Xlt-11 was used for in-vitro characterization. For in-silico characterization, XR sequence (Accession No: Q5BGA7) was used. Results: Xylose reductase from various microorganisms has been studied but the quest for better enzymes, their stability at higher temperature and pH still continues. Xylose reductase from Emericella nidulans Xlt-11 was found NADH dependent and utilizes xylose as its sole substrate for xylitol production. In comparison to whole cells, enzyme exhibited higher enzyme activity at lower cofactor concentration and could tolerate higher substrate concentration. Thermal deactivation profile showed that whole cell catalysts were more stable than enzyme at higher temperature. In-silico analysis of XR sequence from Emericella nidulans (Accession No: Q5BGA7) suggested that the structure was dominated by random coiling. Enzyme sequences have conserved active site with net negative charge and PI value in acidic pH range. Conclusion: Current investigation supported the enzyme’s specific application i.e. bioconversion of xylose to xylitol due to its higher selectivity. In-silico analysis may provide significant structural and physiological information for modifications and improved stability.

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An optogenetic method for investigating presynaptic molecular regulation

Scientific Reports ◽

10.1038/s41598-021-90244-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Yuni Kay ◽

Bruce E. Herring

Keyword(s):

Pyramidal Neurons ◽

Molecular Regulation ◽

Glutamatergic Synapses ◽

Experimental Conditions ◽

Regulatory Pathways ◽

Genetic Manipulations ◽

Postsynaptic Protein ◽

Presynaptic Function ◽

Synaptotagmin 1 ◽

Ca3 Pyramidal Neurons

AbstractWhile efficient methods are well established for studying postsynaptic protein regulation of glutamatergic synapses in the mammalian central nervous system, similarly efficient methods are lacking for studying proteins regulating presynaptic function. In the present study, we introduce an optical/electrophysiological method for investigating presynaptic molecular regulation. Here, using an optogenetic approach, we selectively stimulate genetically modified presynaptic CA3 pyramidal neurons in the hippocampus and measure optically-induced excitatory postsynaptic currents produced in unmodified postsynaptic CA1 pyramidal neurons. While such use of optogenetics is not novel, previous implementation methods do not allow basic quantification of the changes in synaptic strength produced by genetic manipulations. We find that incorporating simultaneous recordings of fiber volley amplitude provides a control for optical stimulation intensity and, as a result, creates a metric of synaptic efficacy that can be compared across experimental conditions. In the present study, we utilize our new method to demonstrate that inhibition of synaptotagmin 1 expression in CA3 pyramidal neurons leads to a significant reduction in Schaffer collateral synapse function, an effect that is masked with conventional electrical stimulation. Our hope is that this method will expedite our understanding of molecular regulatory pathways that govern presynaptic function.

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Autophagy Modulators in Cancer Therapy

International Journal of Molecular Sciences ◽

10.3390/ijms22115804 ◽

2021 ◽

Vol 22 (11) ◽

pp. 5804

Author(s):

Kamila Buzun ◽

Agnieszka Gornowicz ◽

Roman Lesyk ◽

Krzysztof Bielawski ◽

Anna Bielawska

Keyword(s):

Cancer Research ◽

Cancer Therapy ◽

Adverse Effects ◽

Nutrient Deficiency ◽

Molecular Regulation ◽

Regulatory Pathways ◽

Selective Autophagy ◽

Atg Proteins ◽

Different Types ◽

The Relationship

Autophagy is a process of self-degradation that plays an important role in removing damaged proteins, organelles or cellular fragments from the cell. Under stressful conditions such as hypoxia, nutrient deficiency or chemotherapy, this process can also become the strategy for cell survival. Autophagy can be nonselective or selective in removing specific organelles, ribosomes, and protein aggregates, although the complete mechanisms that regulate aspects of selective autophagy are not fully understood. This review summarizes the most recent research into understanding the different types and mechanisms of autophagy. The relationship between apoptosis and autophagy on the level of molecular regulation of the expression of selected proteins such as p53, Bcl-2/Beclin 1, p62, Atg proteins, and caspases was discussed. Intensive studies have revealed a whole range of novel compounds with an anticancer activity that inhibit or activate regulatory pathways involved in autophagy. We focused on the presentation of compounds strongly affecting the autophagy process, with particular emphasis on those that are undergoing clinical and preclinical cancer research. Moreover, the target points, adverse effects and therapeutic schemes of autophagy inhibitors and activators are presented.

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VALINE METABOLISM AND PENICILLIN BIOSYNTHESIS

Journal of Biological Chemistry ◽

10.1016/s0021-9258(18)70521-8 ◽

1958 ◽

Vol 230 (2) ◽

pp. 991-999

Author(s):

Carl M. Stevens ◽

Chester W. de Long

Keyword(s):

Penicillin Biosynthesis

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Identification of the Genetic Basis of Response to de-Acclimation in Winter Barley

International Journal of Molecular Sciences ◽

10.3390/ijms22031057 ◽

2021 ◽

Vol 22 (3) ◽

pp. 1057

Author(s):

Magdalena Wójcik-Jagła ◽

Agata Daszkowska-Golec ◽

Anna Fiust ◽

Przemysław Kopeć ◽

Marcin Rapacz

Keyword(s):

Enzyme Activity ◽

Stress Response ◽

Genetic Basis ◽

Differential Expression Analysis ◽

Winter Barley ◽

Developmental Changes ◽

Molecular Regulation ◽

Quantitative Real Time Pcr ◽

Breeding Lines ◽

Functionally Diverse

Mechanisms involved in the de-acclimation of herbaceous plants caused by warm periods during winter are poorly understood. This study identifies the genes associated with this mechanism in winter barley. Seedlings of eight accessions (four tolerant and four susceptible to de-acclimation cultivars and advanced breeding lines) were cold acclimated for three weeks and de-acclimated at 12 °C/5 °C (day/night) for one week. We performed differential expression analysis using RNA sequencing. In addition, reverse-transcription quantitative real-time PCR and enzyme activity analyses were used to investigate changes in the expression of selected genes. The number of transcripts with accumulation level changed in opposite directions during acclimation and de-acclimation was much lower than the number of transcripts with level changed exclusively during one of these processes. The de-acclimation-susceptible accessions showed changes in the expression of a higher number of functionally diverse genes during de-acclimation. Transcripts associated with stress response, especially oxidoreductases, were the most abundant in this group. The results provide novel evidence for the distinct molecular regulation of cold acclimation and de-acclimation. Upregulation of genes controlling developmental changes, typical for spring de-acclimation, was not observed during mid-winter de-acclimation. Mid-winter de-acclimation seems to be perceived as an opportunity to regenerate after stress. Unfortunately, it is competitive to remain in the cold-acclimated state. This study shows that the response to mid-winter de-acclimation is far more expansive in de-acclimation-susceptible cultivars, suggesting that a reduced response to the rising temperature is crucial for de-acclimation tolerance.

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