مجله پژوهش های سلولی مولکولی (زیست شناسی ایران)
سال سی و ششم شماره 3 (پاییز 1402)

Glycogen synthase kinase 3 beta (GSK3β) is a multifunctional serine/thronine kinase that play as a bottleneck protein in the WNT signaling pathway in various functions of pluripotent stem cells (PSCs) such as Self-renewal, survival and differentiation. Since the inhibition of GSK3β leads to the differentiation of PSCs, the use of appropriate inhibitors that inhibit GSK3β at lower concentrations can be economically affordable. One of the most important inhibitors is CHIR99021, which can improve the culture and differentiation systems of PSCs. Present study aimed to investigate the molecular dynamics (MD) simulation such as Root Means Square Deviation (RMSD), Root Means Square fluctuation (RMSF), number of hydrogen bonds, principal component analysis (PCA), radius of gyration, Gibbs free energy landscape, in the presence and absence of CHIR99021 were evaluated and the stability and structural changes of GSK3β protein were simulated using GROMACS 2021.1 software. In addition, the pharmacokinetic properties of this compound were predicted using Schrӧdinger, LLC, New York, NY, Release 2015-2 software. The results of these studies showed that CHIR99021 binds to the active site of GSK3β through hydrogen bonding and produces its inhibitory effect, thus causing instability of the GSK3β structure. Docking and computational analysis confirmed that this chemical compound can be effectively used for directing cell fate and differentiation of PSCs.

MicroRNAs (miRNAs) constitute a family of small RNA (sRNA) population that regulates the gene expression at the post-transcriptional levels by targeting mRNAs for degradation or by inhibiting protein translation. Although thousands of miRNAs have been identified in many plant species, no studies have been reported on discovering conserved stress-related miRNAs in lentil, one of the most important staple food crops in Iran developing countries. The present study was performed to identify the conserved miRNAs and their target genes in the lentil transcriptome under salts tress. In this study, 55892 unigenes from de novo assembly process of a set of short reads derived from RNA sequencing technology of lentil under control and salt stress conditions were used for the prediction of conserved miRNAs and their target genes. Finally, six potentials miRNAsnamedlcu-miR156, lcu-miR167, lcu-miR169, lcu-miR171, lcu-miR396, and lcu-miR390 belong to six conserved families were identified. Identified miRNAs showed differential expression under salt stress. The results showed that the target genes of the identified miRNAs play an important role in most biological processes such as differentiation, growth, signaling and response to biotic and abiotic stresses. In addition, the results showed that some transcription factors belonging to SBP, C2H2, GRAS, M-type_MADS and MYB families are widely affected by the regulatory process of identified miRNAs. In general, the set of miRNA and their target genes identified in the present study can be used as a useful basis for more in-depth and accurate research on the role of miRNAs in response of lentil to salt stress.

These days, the most cost-effective and accessible way to monitor air pollutants is the use of bio-monitors. Therefore, this study was conducted to biologically monitor temporal changes in the concentration of heavy metals suspended in the air using the lichen transplant technique. For this purpose, lichens of the genus Ramalina were applied. It was transferred from an uncontaminated area (Tirkan village, Babol city) in Hyrcanian forests to the study area near the transit road in Noor city. After three periods of three, six, and nine months of exposure, concentrations of Aluminum, Iron, Zinc, Copper, Lead, Nickel, Vanadium, Chromium, Arsenic, Selenium, Cadmium, Molybdenum, Cobalt in lichen samples (15samples per period) was determined by ICP-MS device. The results showed that Aluminum and Cadmium had the highest and lowest concentrations in all periods, respectively (mean614.06and 0.18 μg / g, respectively). With increasing exposure time, the concentration of metals also increased and this increase showed a significant difference in all metals for the first and Three periods (p <0.05). It was also found that due to the average exposure of control rate (3.37) which was much higher than the severe accumulation limit (1.75), the selected lichen has an acceptable ability to biologically monitor changes in heavy metal concentrations. In addition, using an exposure of control rate to evaluate the rate of change is a better alternative than the evaluation of the concentration of trace elements alone.

Signal peptides can be used to effectively transfer recombinant proteins into chloroplast for their appropriate functionality or storage. In this study, the efficiency of candidate signal peptides was studied using in silico and in vitro approaches. At first, the cleavage sites, ability to transport into chloroplast, and hydrophobicity of 160 signal peptides were analyzed by bioinformatic tools such as Targetp, Tppred, PredSL, and Protoscale. The secondary structures of the transcripts of reporter gene fused to these signal peptides were also predicted. In the next step, signal peptides of epsps and pcaD genes respectively from petunia (Petunia × hybrida) and spinach (Spinacia oleracea) were cloned using specific primers. β-glucuronidase gene and each signal peptides coding sequences were fused together. The resulting fragments were then transferred by Agrobacterium tumefaciens and over-expressed in tobacco (Nicotiana tabacum) as a model plant. Chloroplasts were extracted from transgenic young and green leaves and β-glucuronidase activity was assayed qualitatively by histochemical and quantitatively by fluorometric methods. The results showed that GUS was present and active in chloroplasts and the epsps signal peptide was more effective than pcaD in transferring the target protein. In conclusion, we can speculate that the identified signal sequences have the potential to transfer recombinant proteins into plastids for more effectiveness or for storage and extraction purposes.

Understanding the genetic diversity and the relationships between species and plant ecotypes is an important step to preserve genetic resources. In this study, the genetic diversity of 15 Guava (Psidium guajava) genotypes was investigated using Rapid and ISSR markers in the molecular breeding laboratory of the Faculty of Agriculture, University of Birjand. Nine out of 36 RAPD primers and six out of seven ISSR primers showed polymorphism. In total, RAPD and ISSR primers amplified 80 and 35 bands, respectively, which 54 out of 80 (67.5%) and 25 out of 35 (71.42%) bands were amplified by RAPD and USSR primers, were polymorphic, respectively. The lowest and highest polymorphic information content was observed in RAPD marker in OPAB09 primer (0.13) and OPAB17 primer (0.40) and in ISSR primer in ISSR3 primer (0.19) and ISSR5 primer (0.37), respectively. According to the RAPD marker, genotypes M5 with M4 (0.83) had the highest and genotypes CH5 with R4 (0.19) had the least similarity, respectively. According to ISSR marker, genotypes R2 with R3 (0.86) had the highest and M1 with CH4 (0.12) had the least similarity, respectively. The Cluster analysis classified genotypes according to RAPD marker into five groups and according to ISSR marker into three groups, respectively. In total, the results showed that there is sufficient genetic diversity among Guava genotypes and RAPD and ISSR are useful markers in identifying polymorphic regions and estimating genetic distance and managing genetic resources of Guava.

Peroxidases are one of the most applicable enzyem in the fields of industry, medicine and biotechnology. In this study, comprehensive information on the advantages and disadvantages and also applications of plant peroxidases and nanozymes (with peroxidase-like properties), are provided in a categorized manner using of numerous articles. Peroxidase enzymes are belong to the oxidoreductases group which are found in all living organisms and are classified into different classes, one of the most applicable of which is plant peroxidases. However, applications of peroxidases limit by the some factors such as high cost of purification, low stability and degradation by proteases. Todays, in order to overcome these problems, non protein substances or compounds with peroxidase-like properties, such as nanozymes, have been considered. For industrial applications, peroxidases can be provided by purification from various sources, and also their catalytic activities and stabilities can be optimized using various methods such as environmental engineering and protein engineering, whilest these methods are costly and time consuming. Peroxidase-like nanozymes can be prepared from various materials which their catalytic activities and stabilities can be optimized throuth changing of their size, shape and combination with other materials that are usually easy, fast and cheape. At the same time, problems such as storage and degradation by proteases, which are a challenge for enzymes, are not associated with the nanozymes. Overall, it seems in industrial and medical applications, plant peroxidases can replace by nanozymes.