Changes In Cellular Structure Research Articles

Proteomic study revealed cellular assembly and lipid metabolism dysregulation in sepsis secondary to community-acquired pneumonia

Sepsis is a life-threatening disorder characterized by organ dysfunction and a major cause of mortality worldwide. The major challenge in studying sepsis is its diversity in such factors as age, source of infection and etiology. Recently, genomic and proteomic approaches have improved our understanding of its complex pathogenesis. In the present study, we use quantitative proteomics to evaluate the host proteome response in septic patients secondary to community-acquired pneumonia (CAP). Samples obtained at admission and after 7 days of follow-up were analyzed according to the outcomes of septic patients. The patients’ proteome profiles were compared with age- and gender-matched healthy volunteers. Bioinformatic analyses of differentially expressed proteins showed alteration in the cytoskeleton, cellular assembly, movement, lipid metabolism and immune responses in septic patients. Actin and gelsolin changes were assessed in mononuclear cells using immunofluorescence, and a higher expression of gelsolin and depletion of actin were observed in survivor patients. Regarding lipid metabolism, changes in cholesterol, HDL and apolipoproteins were confirmed using enzymatic colorimetric methods in plasma. Transcriptomic studies revealed a massive change in gene expression in sepsis. Our proteomic results stressed important changes in cellular structure and metabolism, which are possible targets for future interventions of sepsis.

CHIP as a membrane-shuttling proteostasis sensor.

Cells respond to protein misfolding and aggregation in the cytosol by adjusting gene transcription and a number of post-transcriptional processes. In parallel to functional reactions, cellular structure changes as well; however, the mechanisms underlying the early adaptation of cellular compartments to cytosolic protein misfolding are less clear. Here we show that the mammalian ubiquitin ligase C-terminal Hsp70-interacting protein (CHIP), if freed from chaperones during acute stress, can dock on cellular membranes thus performing a proteostasis sensor function. We reconstituted this process in vitro and found that mainly phosphatidic acid and phosphatidylinositol-4-phosphate enhance association of chaperone-free CHIP with liposomes. HSP70 and membranes compete for mutually exclusive binding to the tetratricopeptide repeat domain of CHIP. At new cellular locations, access to compartment-specific substrates would enable CHIP to participate in the reorganization of the respective organelles, as exemplified by the fragmentation of the Golgi apparatus (effector function).

Deblurring Signal Network Dynamics.

To orchestrate the function and development of multicellular organisms, cells integrate intra- and extracellular information. This information is processed via signal networks in space and time, steering dynamic changes in cellular structure and function. Defects in those signal networks can lead to developmental disorders or cancer. However, experimental analysis of signal networks is challenging as their state changes dynamically and differs between individual cells. Thus, causal relationships between network components are blurred if lysates from large cell populations are analyzed. To directly study causal relationships, perturbations that target specific components have to be combined with measurements of cellular responses within individual cells. However, using standard single-cell techniques, the number of signal activities that can be monitored simultaneously is limited. Furthermore, diffusion of signal network components limits the spatial precision of perturbations, which blurs the analysis of spatiotemporal processing in signal networks. Hybrid strategies based on optogenetics, surface patterning, chemical tools, and protein design can overcome those limitations and thereby sharpen our view into the dynamic spatiotemporal state of signal networks and enable unique insights into the mechanisms that control cellular function in space and time.

Erratum to: Synergistic effect of aluminum and ionizing radiation upon ultrastructure, oxidative stress and apoptotic alterations in Paneth cells of rat intestine

Environmental and occupational exposure to aluminum along with ionizing radiation results in serious health problems. This study was planned to investigate the impact of oxidative stress provoked by exposure to ionizing radiation with aluminum administration upon cellular ultra structure and apoptotic changes in Paneth cells of rat small intestine . Animals received daily aluminum chloride by gastric gavage at a dose 0.5 mg/Kg BW for 4 weeks. Whole body gamma irradiation was applied at a dose 2 Gy/week up to 8 Gy. Ileum malondialdehyde, advanced oxidation protein products, and protein carbonyl were assessed as biomarkers of lipid peroxidation along with superoxide dismutase, catalase, and glutathione peroxidase activities as enzyme antioxidants. Moreover, analyses of cell cycle division and apoptotic changes were evaluated by flow cytometry. Intestinal cellular ultra structure was investigated using transmission electron microscope. Oxidative stress assessment in the ileum of rats revealed that aluminum and ionizing radiation exposure either alone or in combination exhibits a significant effect upon the increase in biomarkers of lipid peroxidation along with tumor necrosis factor-α with concomitant significant decrease of the antioxidant enzyme activities. Flow cytometric analyses showed significant alterations in the percentage of cells during cell cycle division phases along with significant increase in apoptotic cells. Ultra structurally, intestinal cellular alterations with marked injury in Paneth cells at the sites of bacterial translocation in the crypt of lumens were recorded. The results of this study have clearly suggested that aluminum exposure and ionizing either alone or in combination induced apoptosis and oxidative stress in the Paneth cells of rat intestine, which appeared to play a major role in the pathogenesis of cellular damage. Furthermore, the interaction of these two intestinal toxic routes was found to be synergistic.

T-tubule remodelling disturbs localized β2-adrenergic signalling in rat ventricular myocytes during the progression of heart failure.

AimsCardiomyocyte β2-adrenergic receptor (β2AR) cyclic adenosine monophosphate (cAMP) signalling is regulated by the receptors’ subcellular location within transverse tubules (T-tubules), via interaction with structural and regulatory proteins, which form a signalosome. In chronic heart failure (HF), β2ARs redistribute from T-tubules to the cell surface, which disrupts functional signalosomes and leads to diffuse cAMP signalling. However, the functional consequences of structural changes upon β2AR-cAMP signalling during progression from hypertrophy to advanced HF are unknown.Methods and resultsRat left ventricular myocytes were isolated at 4-, 8-, and 16-week post-myocardial infarction (MI), β2ARs were stimulated either via whole-cell perfusion or locally through the nanopipette of the scanning ion conductance microscope. cAMP release was measured via a Förster Resonance Energy Transfer-based sensor Epac2-camps. Confocal imaging of di-8-ANNEPS-stained cells and immunoblotting were used to determine structural alterations. At 4-week post-MI, T-tubule regularity, density and junctophilin-2 (JPH2) expression were significantly decreased. The amplitude of local β2AR-mediated cAMP in T-tubules was reduced and cAMP diffused throughout the cytosol instead of being locally confined. This was accompanied by partial caveolin-3 (Cav-3) dissociation from the membrane. At 8-week post-MI, the β2AR-mediated cAMP response was observed at the T-tubules and the sarcolemma (crest). Finally, at 16-week post-MI, the whole cell β2AR-mediated cAMP signal was depressed due to adenylate cyclase dysfunction, while overall Cav-3 levels were significantly increased and a substantial portion of Cav-3 dissociated into the cytosol. Overexpression of JPH2 in failing cells in vitro or AAV9.SERCA2a gene therapy in vivo did not improve β2AR-mediated signal compartmentation or reduce cAMP diffusion.ConclusionAlthough changes in T-tubule structure and β2AR-mediated cAMP signalling are significant even at 4-week post-MI, progression to the HF phenotype is not linear. At 8-week post-MI the loss of β2AR-mediated cAMP is temporarily reversed. Complete disorganization of β2AR-mediated cAMP signalling due to changes in functional receptor localization and cellular structure occurs at 16-week post-MI.

Predisposing factors for atrial fibrillation in the elderly.

Atrial fibrillation (AF) in the elderly occurs as a consequence of cardiovascular aging and an age related increase of comorbidity. Several predisposing factors for AF have been identified for the overall AF population. Most of them, cardiovascular disease in particular, play a role in younger and older patients. The longer time period during which these risk factors can cause structural changes that ultimately lead to AF may, at least in part, explain the association between age and AF. In addition, less well defined age-related changes in cellular electrophysiologic properties and structure predispose to AF in the elderly.

Epoxy foams with tunable acoustic absorption behavior

Herein, epoxy foams with tunable acoustic behavior were innovatively fabricated via non-traditional expandable microspheres. By adjusting the preparation parameters, changes in cellular structure from closed cells to partial open cells were observed, which exhibited tunability and resulted in diverse sound absorption behaviors. Short procuring time, high microsphere contents and foaming temperatures contribute to constructing more open cells and enhancing the sound absorption properties. High absorption coefficient up to 0.75 is achieved. Such a novel light-weight epoxy foam can serve as a promising structural and sound-proof material, and satisfy the needs of many multifunctional systems including vehicles, buildings, aircrafts, etc.

Synergistic effect of aluminum and ionizing radiation upon ultrastructure, oxidative stress and apoptotic alterations in Paneth cells of rat intestine.

Environmental and occupational exposure to aluminum along with ionizing radiation results in serious health problems. This study was planned to investigate the impact of oxidative stress provoked by exposure to ionizing radiation with aluminum administration upon cellular ultra structure and apoptotic changes in Paneth cells of rat small intestine . Animals received daily aluminum chloride by gastric gavage at a dose 0.5mg/Kg BW for 4weeks. Whole body gamma irradiation was applied at a dose 2Gy/week up to 8Gy. Ileum malondialdehyde, advanced oxidative protein products, protein carbonyl and tumor necrosis factor-alpha were assessed as biomarkers of lipid peroxidation, protein oxidation and inflammation respectively along with superoxide dismutase, catalase, and glutathione peroxidase activities as enzymatic antioxidants. Moreover, analyses of cell cycle division and apoptotic changes were evaluated by flow cytometry. Intestinal cellular ultra structure was investigated using transmission electron microscope.Oxidative and inflammatory stresses assessment in the ileum of rats revealed that aluminum and ionizing radiation exposures exhibited a significant effect upon the increase in oxidative stress biomarkers along with the inflammatory marker tumor necrosis factor-α accompanied by a significant decreases in the antioxidant enzyme activities. Flow cytometric analyses showed significant alterations in the percentage of cells during cell cycle division phases along with significant increase in apoptotic cells. Ultra structurally, intestinal cellular alterations with marked injury in Paneth cells at the sites of bacterial translocation in the crypt of lumens were recorded. The results of this study have clearly showed that aluminum and ionizing radiation exposures induced apoptosis with oxidative and inflammatory disturbance in the Paneth cells of rat intestine, which appeared to play a major role in the pathogenesis of cellular damage. Furthermore, the interaction of these two intestinal toxic routes was found to be synergistic.

Microstructure change in wood cell wall fracture from mechanical pretreatment and its influence on enzymatic hydrolysis

Mechanical pretreatment is an effective process for chemical or biochemical conversion of woody biomass. The deconstruction features of the wood cell wall play an important role in its chemical or biochemical processing. In this work, we evaluated the wood cell wall fracture in the early stage of mechanical pretreatment process conducted with various initial moisture contents. Electronic microscopy (i.e., SEM and TEM) and confocal laser scanning microscopy (CLSM) were used to visualize the cellular structure changes due to cell wall fractures.Results reveal that the enzymatic digestibility of micronized wood produced from different initial moisture contents was improved by 2–6 folder than that of the raw material. The types of cell wall fractures after mechanical pretreatment were distinguished by the initial moisture contents of wood. In wood samples with lower moisture content, interwall fracture occurred predominantly at the middle lamella region, while intrawall fracture occurred primarily at inner cell wall layers, with sever breakage in wood fibers for high moisture content samples. Differences in the distribution of surface chemical composition also resulted from different cell wall fractures. Lignin preferentially covered the fracture surface of low-moisture content samples, while carbohydrates were more predominate in high-moisture content samples. These morphological and structural alternation contributed to improving enzymatic digestibility of micronized wood.Findings from this study demonstrate how mechanical pretreatment modifies the fracture features of wood cell wall for further chemical/biochemical reactions.

Morphochemical changes in the substantia nigra cellular structures in Parkinson's disease

to clarify the features of morphochemical changes in the substantia nigra cellular structures in Parkinson's disease. The structural characteristics of the substantia nigra were studied microscopically and quantified using computer morphometric methods at brain autopsies of individuals with Parkinson's disease who had died from intercurrent diseases and those who had no evidence of neurological disorders in their history (a control group). This investigation could clarify the features of morphochemical changes in both the neural network structures and the glial populations of the substantia nigra in Parkinson's disease. The number of neurons containing tyrosine hydroxylase (a marker of dopamine neurons) in the compact part of the substantia nigra (a ventral region) was smaller and the density distribution of Lewy bodies was higher in the patients with Parkinson's disease than in the control group. The accumulation of iron (II) compounds in the cellular elements and neuropile and the increased expression of glial fibrillary acidic protein in Parkinson's disease were more pronounced than those in the controls. Postmortem diagnosis in Parkinson's disease should be based on a full description of a set of neuronal and glial morphochemical and structural changes in the substantia nigra rather than on the identification of cellular markers for the neurodegenerative process.

Effects of the cyclic stretch-induced morphological changes of cellular structures on the ultraviolet radiation resistance in cells

Effects of the cyclic stretch-induced morphological changes of cellular structures on the ultraviolet radiation resistance in cells

In Vitro Neurotoxicity Resulting from Exposure of Cultured Neural Cells to Several Types of Nanoparticles.

Laboratory and industrial production of various nanoparticles, single-walled nanotubes (SWNTs), fullerene (C60), cadmium selenide (CdSe) quantum dots, carbon black (CB), and dye-doped silica nanospheres (NSs), has greatly increased in the past 15 years. However, little research has been done to analyze the toxicity of these materials. With recent studies showing that nano-substances can cross the blood–brain barrier, we examined the neurotoxicity of these manufactured nanoparticles. By employing the rat PC-12 neuronal-like cell line as the basis for our studies, we were able to evaluate the toxicity caused by these five nanoparticles. The level of toxicity was measured by testing for cell viability using the lactate dehydrogenase (LDH) cell viability assay, morphological analysis of changes in cellular structures, and Western blot analyses of αII-spectrin breakdown products (SBDP) as cell death indicators. Our results showed cytotoxicity in nondifferentiated PC-12 cells exposed to CB (10–100 µg/mL), SWNTs (10–100 µg/mL), C60 (100 µg/mL), CdSe (10 µg/mL), CB (500 µg/mL), and dye-doped silicon NSs (10 µg/mL). Exposure to higher concentrations (100 µg/mL) of SWNTs, CB, and C60 increased the formation of SBDP150/145, as well as cell membrane contraction and the formation of cytosolic vacuoles. The incorporations of the nanoparticles into cell cytoplasm were observed using the fluorescent dye-doped NSs in both nondifferentiated and nerve growth factor (NGF)-differentiated PC-12 cells. When PC-12 cells are differentiated, they appeared to be even more sensitive to cytotoxicity of nanoparticles such as CB 10 nm (10–100 µg/mL), CB 100 nm (10–100 µg/mL), and CdSe (1–10 µg/mL).

Comparative proteome analysis in hot pepper (Capsicum annuum L.) after space flight

Hot pepper (Capsicum annuum L.) is an important crop all over the world. To explore and identify differentially expressed proteins of hot pepper after space flight, three space-induced mutants (Y1, Y2 and Y3), which obtained new traits after space flight compared with their control lines (W1 and W2), were analyzed using comparative proteome analysis. In this study, leaf morphological characteristics of five kinds of hot pepper variations were evaluated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Results showed that obvious changes of cellular structure were seen in space induced mutants. Thirty nine out of the 255 differentially expressed proteins were successfully sequenced. Among these 39 proteins, 31 were homologous with known proteins, and the others were set as a hypothetical protein. All identified proteins were further classified into six groups including protein metabolism, energy metabolism and photosynthesis. In conclusion, these findings will benefit for the research of mutagenic mechanisms at the level of proteomics, and provide an effective way for new hot pepper breeding.

The HL-60 Cells Response to Various Particle Sizes of Tetracalcium Phosphate Ceramic Delivery System

The specific objective of this investigation is to study the effect of tetracalcium phosphate (TeCP) delivery system fabricated from three different particle sizes (<38, 45 and 75 um) on the viability of HL-60 cell line in culture. Each TeCP reservoir was fabricated using standard protocols. The sintered microcrystal material were cold pressed at 5000 kg compression load, sterilized and loaded into wells pre-plated with 106 HL-60 cells. At the end of 24, 48, and 72 hours, the supernatants (cell suspension) from the wells were collected for cell count (a hemacytometer method) and lactate dehydrogenase (LDH) assays. The cells were evaluated for structural cellular damage by using conventional histopathological protocols (H&E stain). Results obtained from this investigation suggest the followings: (i) particle sizes are key elements in developing TeCP delivery system, (ii) the use of <38 um particle sizes would be favorable for long duration of delivering biologicals from the TeCP reservoirs due to the viability of HL-60 cells, (iii) LDH activities were directly proportional the particle sizes of the ceramic capsules compared to the control and (iv) there were less cellular structural changes in devices fabricated from <38 um particle sizes and the cells became more reactive with an increase in particle sizes.

Effect of alkaline and high-pressure homogenization on the extraction of phenolic acids from potato peels

Abstract Phenolic acids were extracted from potato peels with NaOH treatment and a high-pressure homogenization (HPH) process. Total phenolic content, total flavonoid content, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity and extraction yield were determined with different treatment conditions. Significant improvement was observed after the alkaline and HPH treatments. HPLC analysis shows that the phenolic compounds contained gallic acid, sinapic acid, vanillic acid, syringic acid, protocatechuic acid, p-coumaric acid, chlorogenic acid, caffeic acid and ferulic acid. The yields of these specific phenolic acids varied with different treatments. Scanning electron microscope, nuclear magnetic resonance and particle size measurements suggest that changes in cellular structure may be the mechanisms for the improvement in extraction rendered by the HPH and NaOH treatments. In conclusion, the combined treatment of NaOH and HPH increased the extraction yield and functionality of the phenolic acids from the potato peel residues. Industry relevance High-pressure homogenization as a process method has been applied widely in food industry. It can help with emulsification and sterilization significantly. But the potential of High-pressure homogenization as an assist method to improve the yield of extraction from food and food waste has not been developed. The positive effect of phenolic and flavonoids has been proved and found in potato peels. However, the release of these bioactive components is a difficulty with traditional method. The High-pressure homogenization can reduce the particle size apparently and release the bioactive compound. For potato peels, the production can be added into bread, meat, beverage, etc. to increase the fiber and nutrition. For other sorts of similar material, the high-pressure homogenization can be a novel to improve the extraction process of bioactive component bound in cell wall instead of inside the cell. In this article, we developed a new method with high-pressure homogenization and alkaline treatment to improve the extraction process dramatically. Meanwhile, the process can be scale up to industry with minor modification and adjustment.

Hypoxia-stimulated cardiac fibroblast production of IL-6 promotes myocardial fibrosis via the TGF-β1 signaling pathway

Interlukin-6 (IL-6) is a multifunctional cytokine produced by several cell types that has a role in fibrosis. Fibroblasts (FBs) maintain this underlying pathogenic change through regulation of IL-6 production; however, its potential functional role in regulating surrounding cellular structural changes during ischemic myocardial remodeling remains unexplored. Here, we generated FBs, cardiomyocytes (CMs), and blood vascular endothelial cells (ECs) from the ventricles of neonatal rats. IL-6 was then overexpressed in FBs and the cells were treated with IL-6 receptor inhibitor (IL6RI), TGF-β1 receptor inhibitor (TβRI), or MMP2/MMP9 inhibitor (MMPI) using monoculture or coculture models under hypoxic conditions. The results indicate that overexpression of IL-6 is sufficient to induce myofibroblastic proliferation, differentiation, and fibrosis, probably via increased TGF-β1-mediated MMP2/MMP3 signaling. The use of IL6RI, TβRI, or MMPI diminished these effects. In addition, IL-6 activated the apoptosis-associated factors Caspase3 and Smad3, and decreased the expression of anti-apoptotic factor Bcl2, resulting in apoptosis of CMs under hypoxic coculture: IL6RI or TβRI inhibited these effects. Unexpectedly, IL-6-overexpressing FBs significantly increased the angiogenesis of ECs, which involved significant increases in the expression of proangiogenic growth factors. Treatment of FBs with IL6RI or TβRI in coculture with ECs reduced the levels of secreted proangiogenic growth factors, and the angiogenesis of ECs was significantly downregulated. Thus, IL-6 functions in ischemic myocardial remodeling through multifunctional reprogramming of hypoxia-associated FBs towards fibrosis via upregulation of the TGF-β1 signaling pathway.

Antifungal organoselenium compound loaded nanoemulsions stabilized by bifunctional cationic surfactants

Over last few decades, organoselenium compounds have been extensively studied in organic and medicinal chemistry. Ebselen (2-phenylbenzisoselenazol-3(2H)-one, BSe) and its analogues have emerged as potential pharmaceuticals and promising catalysts of various oxidation reactions and potential pharmaceuticals. For instance, their biological interest relies on their antioxidant, anti-inflammatory and glutathione peroxidase-like activities as well as antimicrobial, antiviral and chemopreventive effects. One of the major obstacles for their practical use is poor water solubility. For this purpose the potential of dicephalic cationic surfactants, N,N-bis[3,3′-(trimethylammonio)propyl]alkylamide dichlorides, to form physically stable nanoemulsion-based drug carriers in the presence of a variety of oils (oleic acid, Capmul MCM and PG-8) and the organoselenium-derived cargo was explored. Nanoemulsions were characterized by visual and microscopic observations, as well as dynamic light scattering (DLS) measurements of particle size and distributions. Results of transmission electron microscopy (TEM) and DLS showed that nearly spherical droplets of very similar size were obtained, with oleic acid bringing best properties. Time-depended size (DH) and ξ-potential measurements, dispersion stability test and kinetic stability studies with multiple light scattering (MLS) technique proved high colloid stability of the fabricated systems. Positively charged nanoemulsions with high ξ-potential values up to 87mV showed no significant evolution in backscattering profiles. The nanoemulsions were evaluated for antimicrobial efficacy towards Candida albicans and its biofilm. Strong antifungal activity was observed, with deleterious morphological changes in cellular structures and yeasts cell surface alterations. In conclusion, the designed oil-in-water nanoemulsion-based carriers, stabilized by dicephalic cationic surfactants can comprise a promising delivery system for poorly water soluble organoselenium derivatives of efficient antimicrobial activities.

Assessing physio-macromolecular effects of lactic acid on Zygosaccharomyces bailii cells during microaerobic fermentation.

The ability of Zygosaccharomyces bailii to grow at low pH and in the presence of considerable amounts of weak organic acids, at lethal condition for Saccharomyces cerevisiae, increased the interest in the biotechnological potential of the yeast. To understand the mechanism of tolerance and growth effect of weak acids on Z. bailii, we evaluated the physiological and macromolecular changes of the yeast exposed to sub lethal concentrations of lactic acid. Lactic acid represents one of the important commodity chemical which can be produced by microbial fermentation. We assessed physiological effect of lactic acid by bioreactor fermentation using synthetic media at low pH in the presence of lactic acid. Samples collected from bioreactors were stained with propidium iodide (PI) which revealed that, despite lactic acid negatively influence the growth rate, the number of PI positive cells is similar to that of the control. Moreover, we have performed Fourier Transform Infra-Red (FTIR) microspectroscopy analysis on intact cells of the same samples. This technique has been never applied before to study Z. bailii under this condition. The analyses revealed lactic acid induced macromolecular changes in the overall cellular protein secondary structures, and alterations of cell wall and membrane physico-chemical properties.

Impedimetric real-time monitoring of neural pluripotent stem cell differentiation process on microelectrode arrays

In today's neurodevelopment and -disease research, human neural stem/progenitor cell-derived networks represent the sole accessible in vitro model possessing a primary phenotype. However, cultivation and moreover, differentiation as well as maturation of human neural stem/progenitor cells are very complex and time-consuming processes. Therefore, techniques for the sensitive non-invasive, real-time monitoring of neuronal differentiation and maturation are highly demanded.Using impedance spectroscopy, the differentiation of several human neural stem/progenitor cell lines was analyzed in detail. After development of an optimum microelectrode array for reliable and sensitive long-term monitoring, distinct cell-dependent impedimetric parameters that could specifically be associated with the progress and quality of neuronal differentiation were identified. Cellular impedance changes correlated well with the temporal regulation of biomolecular progenitor versus mature neural marker expression as well as cellular structure changes accompanying neuronal differentiation. More strikingly, the capability of the impedimetric differentiation monitoring system for the use as a screening tool was demonstrated by applying compounds that are known to promote neuronal differentiation such as the γ-secretase inhibitor DAPT.The non-invasive impedance spectroscopy-based measurement system can be used for sensitive and quantitative monitoring of neuronal differentiation processes. Therefore, this technique could be a very useful tool for quality control of neuronal differentiation and moreover, for neurogenic compound identification and industrial high-content screening demands in the field of safety assessment as well as drug development.

Connecting common genetic polymorphisms to protein function: A modular project sequence for lecture or lab

Single nucleotide polymorphisms (SNPs) in DNA can result in phenotypes where the biochemical basis may not be clear due to the lack of protein structures. With the growing number of modeling and simulation software available on the internet, students can now participate in determining how small changes in genetic information impact cellular protein structure and function. We have developed a modular series of activities to engage lab or lecture students in examining the basis for common phenotypes. The activities range from basic phenotype testing/observation to DNA sequencing and simulation of protein structure and dynamics. We provide as an example study of the bitterness receptor TAS2R38 and PTC tasting, however these activities are applicable to other SNPs or genomic variants with a direct connection to an observable phenotype. These activities are modular and can be mixed to meet the student capabilities and infrastructure availability. The complete sequence of activities will demonstrate the direct connection between gene structure, protein structure and organism function. © 2016 by The International Union of Biochemistry and Molecular Biology, 44(6):526-536, 2016.