SEARCH · bioRxiv Science

Results for “Molecular Biology”

Search indexed bioRxiv preprints in genomics, neuroscience, cell biology and bioinformatics. Read source abstracts and check manuscript versions; preprints are not peer reviewed.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 199 records · Page 11Linked to original sources

bioRxiv2017

Structural basis for terminal loop recognition and processing of pri-miRNA-18a by hnRNP A1

Post-transcriptional mechanisms play a predominant role in the control of microRNA (miRNA) production. Recognition of the terminal loop of precursor miRNAs by RNA-binding proteins (RBPs) influences their processing; however, the mechanistic and structural basis for how levels of individual or subsets of miRNAs are regulated is mostly unexplored. We previously described a role for hnRNP A1, an RBP implicated in many aspects of RNA processing, as an auxiliary factor that promotes the Microprocessor-mediated processing of pri-mir-18a. Here, we reveal the mechanistic basis for this stimulatory role of hnRNP A1 by combining integrative structural biology with biochemical and functional assays. We demonstrate that hnRNP A1 forms a 1:1 complex with pri-mir-18a that involves binding of both RNA recognition motifs (RRMs) to cognate RNA sequence motifs in the conserved terminal loop of pri-mir-18a. Terminal loop binding induces an allosteric destabilization of base-pairing in the pri-mir-18a stem that promotes its down-stream processing. Our results highlight terminal loop RNA recognition by RNA-binding proteins as a general principle of miRNA biogenesis and regulation.

molecular biology↗

bioRxiv2018

Aspergillus niger citrate exporter revealed by comparison of two alternative citrate producing conditions

Currently, there is no consensus regarding the mechanism underlying Aspergillus niger citrate biosynthesis and secretion, although it is amongst the most studied biotechnological production processes. Carbon excess relative to various other medium constituents is key, but the complex interplay between the limiting factors required for extracellular citrate accumulation remains elusive. It is thought that one of the industrial bottlenecks for citrate production is citrate export, however, no A. niger citrate exporter has yet been identified. Here, we show that the phenotype of increased extracellular citrate accumulation can have fundamentally different underlying mechanisms, depending on how this response is triggered, and that combining gene expression analyses of the different conditions can lead to the compilation of a shortlist of the most promising citrate exporter candidates. Specifically, we found that varying the amount and type of supplement of an arginine auxotrophic A. niger strain shows down-regulation of citrate metabolising enzymes in the condition in which more citrate is accumulated extracellularly. This contrasts with the transcriptional adaptations triggered by iron limitation, which also induces increased A. niger citrate production. By combining data obtained from these two manners of inducing comparatively high extracellular citrate accumulation, we were able to compile a shortlist of the most likely citrate transporter candidates. Two of the most promising candidates were tested in the yeast Saccharomyces cerevisiae, one of which showed the ability to secrete citrate. Deletion of the endogenous A. niger gene encoding the corresponding transporter abolished the ability of this fungus to secrete citrate. Instead, under conditions that usually favour A. niger citrate production, we found increased accumulation of extracellular oxalate. Our findings provide steps in untangling the complex interplay of different mechanisms underlying A. niger citrate accumulation, and we identify, for the first time, a fungal citrate exporter, offering a valuable tool for improvement of A. niger as biotechnological cell-factory for organic acid production.\n\nAuthor SummaryCitrate is widely applied as acidifier, flavouring and chelating agent. Industrial citrate production currently relies on the filamentous fungus Aspergillus niger. Although the industrial production process using A. niger has vastly improved since initiated almost 100 years ago, citrate export remains a bottleneck. Here, we studied the gene expression pattern of A. niger under various citrate producing conditions. Using these expression patterns and different computational approaches, we compiled a shortlist of putative citrate exporter candidates. In this way, we were able to identify a gene encoding a transporter protein capable of citrate export. We show that the yeast Saccharomyces cerevisiae, normally a citrate non-producer, secretes detectable amounts of citrate when harbouring this gene. In addition, we verify the biological function of this gene in A. niger itself, as removing this gene resulted in a citrate non-producing phenotype, which is atypical for this fungus. This finding is particularly exciting, as it is the first identification of a eukaryotic citrate exporter. With this, we not only provide a tool for improvement of industrial citrate production, but knowledge of this gene should help develop new methods for improvement of A. niger as biotechnological cell-factory for the production of other organic acids.

molecular biology↗

bioRxiv2017

Profiling Of Lysine-Acetylated Proteins In Human Urine

Biomarker is the measurable change associated with a physiological or pathophysiological process, its nature is change. Contrast to the blood which is under homeostatic controls, urine reflects changes in the body earlier and more sensitive therefore is a better biomarker source. Lysine acetylation is an abundant and highly regulated post-translational modification. It plays a pivotal role in modulating diverse biological processes and is associated with various important diseases. Enrichment or visualization of proteins with specific post-translational modifications provides a method for sampling the urinary proteome and reducing sample complexity. In this study, we used anti-acetyllysine antibody-based immunoaffinity enrichment combined with high-resolution mass spectrometry to profile lysine-acetylated proteins in normal human urine. A total of 629 acetylation sites on 315 proteins were identified, including some very low-abundance proteins. This is the first proteome-wide characterization of lysine acetylation proteins in normal human urine. Our dataset provides a useful resource for the further discovery of the lysine acetylated proteins as biomarker in urine.

molecular biology↗

bioRxiv2018

Identification of PTBP1 responsible for caspase dependent YRNA cleavage

Some RNAs such as 28S rRNA, U1 snRNA, and Y RNAs are known to be cleaved during apoptosis. As the underlying mechanism is yet unclear, the functions and biological significance of RNA degradation in apoptosis remain elusive. We previously identified novel, functional small RNAs named AGO-taxis small RNA (ASR) that are specifically bound to AGO1. Here, we investigated ASR biogenesis, which appears to be non-canonical. Y RNAs, non-coding RNAs degraded during apoptosis, were identified as the precursors of several ASRs. Cell-free analysis combined with fractionation methods revealed that the apoptosis-specific biogenesis of ASRs or Y RNA degradation was induced by PTBP1--an endoribonuclease inhibitor of Y RNAs. PTBP1, a splicing factor, was truncated by caspase 3, which subsequently activated endoribonuclease to induce biogenesis of ASRs and Y RNA cleavage.

molecular biology↗

bioRxiv2017

Post-Transcriptional Control Of EMT Is Coordinated Through Combinatorial Targeting By Multiple microRNAs

Epithelial-mesenchymal transition (EMT) is a process whereby cells undergo reversible phenotypic change, losing epithelial characteristics and acquiring mesenchymal attributes. While EMT underlies normal, physiological programs in embryonic tissue development and adult wound healing, it also contributes to cancer progression by facilitating metastasis and altering drug sensitivity. Using a cell model of EMT (human mammary epithelial (HMLE) cells), we show that miRNAs act as an additional regulatory layer over and above the activity of the transcription factors with which they are closely associated. In this context, miRNAs serve to both enhance expression changes for genes with EMT function, whilst simultaneously reducing transcriptional noise in non-EMT genes. We find that members of the polycistronic miR-200c~141 and miR-183~182 clusters (which are decreased during HMLE cell EMT and are associated with epithelial gene expression in breast cancer patients) co-regulate common targets and pathways to enforce an epithelial phenotype. We demonstrate their combinatorial effects are apparent much closer to endogenous expression levels (and orders of magnitude lower than used in most studies). Importantly, the low levels of combinatorial miRNAs that are required to exert biological function ameliorate the \"off-target\" effects on gene expression that are a characteristic of supra-physiologic miRNA manipulation. We argue that high levels of over-expression characteristic of many miRNA functional studies have led to an over-estimation of the effect of many miRNAs in EMT regulation, with over 130 individual miRNAs directly implicated as drivers of EMT. We propose that the functional effects of co-regulated miRNAs that we demonstrate here more-accurately reflects the endogenous post-transcriptional regulation of pathways, networks and processes, and illustrates that the post-transcriptional miRNA regulatory network is fundamentally cooperative.

molecular biology↗

bioRxiv2018

Histone deacetylase activity is required for Botrylloides leachii whole body regeneration.

The colonial tunicate Botrylloides leachii is exceptional at regenerating from a piece of vascular tunic after loss of all adults from the colony. Previous transcriptome analyses indicate a brief period of healing before regeneration of a new adult (zooid) in as little as 8-10 days. However, there is little understanding of how the resulting changes to gene expression, required to drive regeneration, are initiated and how the overall process is regulated. Rapid changes to gene expression often occur in response to chromatin changes, mediated by histone modifications such as histone acetylation. Here, we investigated a group of key epigenetic modifiers, histone deacetylases (HDAC) that are known to play an important role in many biological processes such as development, healing and regeneration.\n\nThrough our transcriptome data, we identified and quantified the expression levels of HDAC and histone acetyltransferase (HAT) enzymes during whole body regeneration (WBR). To determine if HDAC activity is required for WBR, we inhibited its action using valproic acid (VPA) and Trichostatin A (TSA). HDAC inhibition prevented the final morphological changes normally associated with WBR and resulted in aberrant gene expression. B. leachii genes including Slit2, TGF-{square}, Piwi and Fzd4 all showed altered gene expression upon HDAC inhibition in comparison to the control samples. Additionally, atypical expression of Bl_Piwi was found in immunocytes upon HDAC inhibition.\n\nTogether, these results show that HDAC function, specifically HDAC I/IIa class enzymes, are vital for B. leachii to undergo WBR successfully.

molecular biology↗

bioRxiv2016

Quantitative analysis of 3D alignment quality: itsimpact on soft-validation, particle pruning andhomogeneity analysis

Single Particle Analysis using cryo-electron microscopy is a structural biology technique to capture the three-dimensional conformation of biological macromolecules. The projection images used to construct the 3D density map are characterized by a very low signal-to-noise ratio to minimize radiation damage in the samples. As a consequence, the 3D alignment process is a challenging and error prone task and this job usually determines the success or failure of the macromolecule reconstruction. In this work, we present a soft-alignment validation approach, which can quantify the alignment precision and accuracy as well as the data homogeneity of the single particles when they are confronted with the resultant reconstructed 3DEM map. We have also applied this method to data homogeneity analysis and particle pruning, improving the data quality and as a consequence the final map resolution.

molecular biology↗

bioRxiv2018

Error-correcting DNA barcodes for high-throughput sequencing

Many large-scale high-throughput experiments use DNA barcodes--short DNA sequences prepended to DNA libraries--for identification of individuals in pooled biomolecule populations. However, DNA synthesis and sequencing errors confound the correct interpretation of observed barcodes and can lead to significant data loss or spurious results. Widely-used error-correcting codes borrowed from computer science (e.g., Hamming and Levenshtein codes) do not properly account for insertions and deletions in DNA barcodes, even though deletions are the most common type of synthesis error. Here, we present and experimentally validate FREE (Filled/truncated Right End Edit) barcodes, which correct substitution, insertion, and deletion errors, even when these errors alter the barcode length. FREE barcodes are designed with experimental considerations in mind, including balanced GC content, minimal homopolymer runs, and reduced internal hairpin propensity. We generate and include lists of barcodes with different lengths and error-correction levels that may be useful in diverse high-throughput applications, including >106 single-error correcting 16-mers that strike a balance between decoding accuracy, barcode length, and library size. Moreover, concatenating two or more FREE codes into a single barcode increases the available barcode space combinatorially, generating lists with > 1015 error-correcting barcodes. The included software for creating barcode libraries and decoding sequenced barcodes is efficient and designed to be user-friendly for the general biology community.\n\nSIGNIFICANCE STATEMENTModern high-throughput biological assays study pooled populations of individual members by labeling each member with a unique DNA sequence called a \"barcode.\" DNA barcodes are frequently corrupted by DNA synthesis and sequencing errors, leading to significant data loss and incorrect data interpretation. Here, we describe a novel error-correction strategy to improve the efficiency and statistical power of DNA barcodes. To our knowledge, this is the first report of an error-correcting method that accurately handles insertions and deletions in DNA barcodes, the most common type of error encountered during DNA synthesis and sequencing, resulting in order-of-magnitude increases in accuracy, efficiency, and signal-to-noise. The accompanying software package makes deployment of these barcodes effortless for the broader experimental scientist community.

molecular biology↗

bioRxiv2017

Affinity-mass spectrometric technologies for quantitative proteomics in biological fluids

Proteins are the functional molecules in organisms and are therefore excellent biomarker candidates for a diversity of diseases. Immunoassays and mass spectrometry (MS) are two major technologies being used in proteomics; however, they either lack specificity or sensitivity. An emerging trend is to combine immunoassays with MS (which we call \"affinity-MS\"). This is an important milestone in quantitative proteomics, making it possible to measure low-abundance proteins with high specificity. The targeted enrichment and the assignment of mass-to-charge ratios to different molecules provide two selection criteria, making affinity-MS highly specific. Picogram-per-milliliter limits of detection have been obtained for many proteins. Furthermore, multiplexing capacity of >150 proteins has been achieved. This article reviews different formats of affinity-enrichment methods, and demonstrates how they are interfaced with both electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI) MS. The pros and cons of these techniques are compared, and future prospectives are discussed.

molecular biology↗

bioRxiv2018

Interaction of modified oligonucleotides with nuclear proteins, formation of novel nuclear structures and sequence-independent effects on RNA processing

Oligonucleotides and nucleic acid analogues that alter gene expression are showing therapeutic promise for selected human diseases. The modification of synthetic nucleic acids to protect against nuclease degradation and to influence drug function is common practice, however, such modifications may also confer unexpected physicochemical and biological properties. Here we report backbone-specific effects of modified oligonucleotides on subnuclear organelles, altered distribution of nuclear proteins, the appearance of novel structured nuclear inclusions, and modification of RNA processing in cultured cells transfected with antisense oligonucleotides on a phosphorothioate backbone. Phosphodiester and phosphorodiamidate morpholino oligomers elicited no such consequences. Disruption of subnuclear structures and proteins elicit severe phenotypic disturbances, revealed by transcriptomic analysis of fibroblasts exhibiting such disruption. These data suggest that the toxic effects and adverse events reported after clinical evaluation of phosphorothioate nucleic acid drugs may be mediated, at least in part, by non-specific interaction of nuclear components with the phosphorothioate backbone.

molecular biology↗

bioRxiv2018

Single-molecule imaging of mRNA localization and regulation during the integrated stress response

Biological phase transitions form membrane-less organelles that generate distinct cellular environments. How molecules are partitioned between these compartments and the surrounding cellular space and the functional consequence of this localization is not well understood. Here, we report the localization of mRNA to stress granules(SGs) and processing bodies(PBs), which are distinct biomolecular condensates, and its effect on translation and mRNA degradation during the integrated stress response. Using single mRNA imaging in living human cells, we find that the interactions of mRNAs with SGs and PBs have different dynamics and that specific RNA binding proteins can anchor mRNAs within these compartments. During recovery from stress, mRNAs that were within SGs and PBs are translated and degraded at similar rates as their cytosolic counterparts.

molecular biology↗

bioRxiv2016

Transcriptomic Signatures for Ovulation in Vertebrates

Recently, we found anovulation in nuclear progestin receptor (Pgr) knockout (Pgr-KO) zebrafish, which offers a new model for examining Pgr regulated genes and pathways that are important for ovulation and fertility. In this study, we examined expression of all transcripts using RNA-Seq in pre-ovulatory follicular cells collected after the final oocyte maturation, but prior to ovulation, from wild-type (WT) or Pgr-KO fish. Differential expression analysis revealed 2,888 genes significantly differentially expressed between WT and Pgr-KO fish. Among those, 1,230 gene transcripts were significantly more expressed, while 1,658 genes were significantly less expressed in WT than those in Pgr-KO. We then retrieved and compared transcriptional data from online databases and further identified 661 conserved genes in fish, mice, and humans, that showed similar levels of high (283 genes) or low (387) expression in animals that were ovulating compared to those with no ovulation. For the first time, ovulatory genes and their involved biological processes and pathways were also visualized using Enrichment Map and Cytoscape. Intriguingly, enrichment analysis indicated the genes with higher expression were involved in multiple ovulatory pathways and processes such as inflammatory response, angiogenesis, cytokine production, cell migration, chemotaxis, MAPK, focal adhesion, and cytoskeleton reorganization. In contrast, the genes with lower expression were mainly involved DNA replication, DNA repair, DNA methylation, RNA processing, telomere maintenance, spindle assembling, nuclear acid transport, catabolic processes, nuclear and cell division. Our results indicate that a large set of genes (>3,000) are differentially regulated in the follicular cells in zebrafish prior to ovulation, terminating programs including growth and proliferation, and beginning processes including the inflammatory response and apoptosis. Further studies are required to establish relationships among these genes and an ovulatory circuit in zebrafish model.

Molecular Biology↗

bioRxiv2018

Distinct control of PERIOD2 degradation and circadian rhythms by the oncoprotein MDM2

The circadian clock relies on post-translational modifications to set the timing for degradation of core regulatory components and, thus, sets clock progression. Ubiquitin-modifying enzymes targeting clock components for degradation are known to mostly recognize phosphorylated substrates. A case in point is the circadian factor PERIOD 2 (PER2) whose phospho-specific turnover involves its recognition by {beta}-transducin repeat containing proteins ({beta}-TrCPs). Yet, the existence of this unique mode of regulation of PER2s stability falls short of explaining persistent oscillatory phenotypes reported in biological systems lacking functional elements of the phospho-dependent PER2 degradation machinery.\n\nIn this study, we challenge the phosphorylation-centric view that PER2 degradation enhances circadian rhythm robustness by i) identifying the PER2:MDM2 endogenous complex, ii) establishing PER2 as a previously uncharacterized substrate for MDM2, iii) revealing an alternative phosphorylation-independent mechanism for PER2 ubiquitin-mediated degradation, iv) pinpointing residues for ubiquitin modification, and v) establishing the importance of MDM2-mediated PER2 turnover for defining the circadian period length. Our results not only expand MDM2s suite of specific substrates beyond the cell cycle to include circadian components but also uncover novel regulatory players that likely impact our view of how other mechanisms crosstalk and modulate the clock itself.

molecular biology↗

bioRxiv2013

Water and the biology of prions and plaques

This is an attempt to account for the insolubility and/or aggregation of prions and plaques in terms of a model of water consisting of an equilibrium between high density and low density microdomains. Hydrophobic molecules, including proteins, accumulate selectively into stable populations, enriched in high density water, at charged sites on biopolymers. In enriched high density water, proteins are probably partially unfolded and may precipitate out when released. All extracellular matrices contain such charged polymers. Prions, which have been shown to accumulate in soils and clays containing silicates and aluminates also probably accumulate in extracellular matrices.\n\nRelease of proteins follows hydrolysis of the charged groups by highly reactive high density water. This is normally a slow process but is greatly accelerated by urea. Plaques may form with age and disease because of accumulation of urea and, perhaps, glucose in the blood. This favours precipitation of proteins emerging from matrices, rather than refolding and solution. Dialysis should, therefore, interfere with plaque formation and impede the development of some age-related diseases.

Molecular Biology↗

bioRxiv2015

Identification of novel transcriptional regulators of PKA subunits in Saccharomyces cerevisiae by Quantitative Promoter–Reporter Screening

The cAMP dependent protein kinase (PKA) signaling is a broad specificity pathway that plays important roles in the transduction of environmental signals triggering precise physiological responses. cAMP-signal transduction specificity is achieved and controlled at several levels. The Saccharomyces cereviciae PKA holoenzyme consists of two catalytic subunits encoded by TPK1, TPK2 and TPK3 genes, and two regulatory subunits encoded by BCY1 gene. In this work we studied the activity of these gene promoters using a reporter-synthetic genetic array screen, with the goal of identifying novel regulators of PKA subunits expression. Gene ontology (GO) analysis of the regulators identified showed that these regulators were enriched for annotations associated with roles in several GO biological process, as lipid and phosphate metabolism or transcription regulation and regulate all or some of the four promoters. Further characterization of the effect of these pathways on promoter activity and mRNA levels pointed to inositol, inositol polyphosphates, choline and phosphate as novel upstream signals that regulate transcription of PKA subunit genes. In addition, within each category there are genes that regulate only one of the promoters and genes that regulate more than one of them at the same time. These results support the role of transcription regulation of each PKA subunit in cAMP specificity signaling. Interestingly, many of the known targets of PKA phosphorylation are associated with the identified pathways, opening the possibility of a reciprocal regulation in which PKA would be coordinating different metabolic pathways and these processes would in turn, regulate expression of the kinase subunits.

Molecular Biology↗

bioRxiv2018

Discovery of a two protease DNA damage checkpoint recovery mechanism

The DNA damage response is a signaling pathway found throughout biology. In many bacteria the DNA damage checkpoint is enforced by inducing expression of a small, membrane bound inhibitor that delays cell division providing time to repair damaged chromosomes. How cells sense successful DNA repair and promote checkpoint recovery is unknown. By using a high-throughput, forward genetic screen, we identified two unrelated proteases, YlbL and CtpA, that promote DNA damage checkpoint recovery in Bacillus subtilis. Deletion of both proteases leads to accumulation of the checkpoint protein YneA. DNA damage sensitivity and increased cell elongation in protease mutants depends on yneA. Further, expression of YneA in protease mutants was sufficient to inhibit cell proliferation. Finally, we show that one of the two proteases, CtpA, directly cleaves YneA in vitro. With these results, we report the mechanism for DNA damage checkpoint recovery in bacteria that use membrane bound cell division inhibitors.

molecular biology↗

bioRxiv2018

Uncoupling DNA- and RNA-directed DNA methylation at Rasgrf1

Long noncoding RNAs (lncRNAs) have garnered much attention as possible links between DNA sequence and the protein factors that mediate DNA methylation. However, the mechanisms by which DNA methylation is directed to specific genomic locations remain poorly understood. We previously identified a lncRNA in mouse, the pitRNA, that was implicated in the control of DNA methylation at the imprinted Rasgrf1 locus. The pitRNA is transcribed in the developing male germline antisense to the differentially methylated region (DMR) that harbors paternal allele methylation, and is driven by a series of tandem repeats that are necessary for imprinted methylation.\n\nMitoPLD, a factor necessary for piRNA biogenesis, both processes piRNAs from the pitRNA, and is necessary for complete methylation at the locus, along with piRNA binding proteins. Using two independent mouse systems where pitRNA transcription is driven by the doxycycline-inducible Tet Operator, we demonstrate that pitRNA transcription across the DMR is insufficient for imprinted methylation, and that the Rasgrf1 repeats have additional, critical cis-acting roles for imparting DNA methylation to Rasgrf1, independently of their control of pitRNA transcription. Furthermore, pitRNA overexpression and oocyte loading of pitRNA is insufficient to induce transallelic and transgenerational effects previously reported for Rasgrf1. Notably, manipulation of the pitRNA with the TetOFF system led to transcriptional perturbations over a broad chromosomal region surrounding the inserted Tet Operator, revealing that the effects of this regulatory tool are not localized to a single target gene.\n\nAUTHOR SUMMARYDNA methylation is a heritable genetic modification known to impact vital biological processes. While the proteins that establish, maintain, and remove DNA methylation are well characterized, the mechanisms by which these proteins are directed to specific genetic sequences are poorly understood. We have previously demonstrated that DNA methylation at the imprinted Rasgrf1 locus requires a DNA element with a series of tandem repeats. These repeats act as a promoter for a long noncoding RNA, the pitRNA, which is targeted by a small noncoding RNA pathway known to silence viral elements in the male germline via DNA methylation. We queried the sufficiency of the pitRNA to mediate DNA methylation at Rasgrf1. We show that, in the absence of the repeats, the pitRNA expression is insufficient to establish imprinted methylation. This work supports a pitRNA-independent mechanism for methylation at Rasgrf1, and a critical cis-acting role for the tandem repeats separate from their control of pitRNA transcription.

molecular biology↗

bioRxiv2018

Epicatechin modulates stress-resistance in C. elegans via Insulin/IGF-1 signaling pathway

The nematode Caenorhabditis elegans has been used to examine the influence of epicatechin (EC), an abundant flavonoid in the human diet, in some stress biomarkers (ROS production, lipid peroxidation and protein carbonylation). Furthermore, the ability of EC to modulate the expression of some key genes in the insulin/IGF-1 signaling pathway (IIS), involved in longevity and oxidative or heat shock stress response, has also been explored. The final aim was to contribute to the elucidation of the mechanisms involved in the biological effects of flavonoids. The results showed that EC-treated wild-type C. elegans exhibited increased survival and reduced oxidative damage of biomolecules when submitted to thermal stress. EC treatment led to a moderate elevation in ROS levels, which might activate endogenous mechanisms of defense protecting against oxidative insult. The enhanced stress resistance induced by EC was found to be mediated through the IIS pathway, since assays in daf-2, age-1, akt-1, akt-2, sgk-1, daf-16, skn-1 and hsf-1 loss of function mutant strains failed to show any heat-resistant phenotype against thermal stress when treated with EC. Consistently, EC treatment upregulated the expression of some stress resistance associated genes, such as gst-4, hsp-16.2 and hsp-70, which are downstream regulated by the IIS pathway.

molecular biology↗