RESUMEN
The SOX transcription factor family is pivotal in controlling aspects of development. To identify genotype-phenotype relationships of SOX proteins, we performed a non-biased study of SOX using 1890 open-reading frame and 6667 amino acid sequences in combination with structural dynamics to interpret 3999 gnomAD, 485 ClinVar, 1174 Geno2MP, and 4313 COSMIC human variants. We identified, within the HMG (High Mobility Group)- box, twenty-seven amino acids with changes in multiple SOX proteins annotated to clinical pathologies. These sites were screened through Geno2MP medical phenotypes, revealing novel SOX15 R104G associated with musculature abnormality and SOX8 R159G with intellectual disability. Within gnomAD, SOX18 E137K (rs201931544), found within the HMG box of ~0.8% of Latinx individuals, is associated with seizures and neurological complications, potentially through blood-brain barrier alterations. A total of 56 highly conserved variants were found at sites outside the HMG-box, including several within the SOX2 HMG-box-flanking region with neurological associations, several in the SOX9 dimerization region associated with Campomelic Dysplasia, SOX14 K88R (rs199932938) flanking the HMG box associated with cardiovascular complications within European populations, and SOX7 A379V (rs143587868) within an SOXF conserved far C-terminal domain heterozygous in 0.716% of African individuals with associated eye phenotypes. This SOX data compilation builds a robust genotype-to-phenotype association for a gene family through more robust ortholog data integration.
Asunto(s)
Proteínas del Grupo de Alta Movilidad , Factores de Transcripción SOX , Humanos , Proteínas del Grupo de Alta Movilidad/química , Proteínas del Grupo de Alta Movilidad/genética , Proteínas del Grupo de Alta Movilidad/metabolismo , Factores de Transcripción SOX/genética , Secuencia de Aminoácidos , Dimerización , Genotipo , Factores de Transcripción SOXF/genética , Factores de Transcripción SOXF/metabolismo , Factores de Transcripción SOXB2/genética , Factores de Transcripción SOXB2/metabolismo , Factores de Transcripción SOXE/genéticaRESUMEN
Fibrodysplasia Ossificans Progressiva (FOP) is a rare congenital intractable disease associated with a mutation in ACVR1 gene, characterized by skeleton malformations. Ascorbic acid (AA) and propranolol (PP) in combination is reported to minimize flare-ups in patients. FOP leukocyte phenotype may possibly be modulated by AA and PP treatment. In this study, expression of 22 potential target genes was analyzed by RT-PCR in peripheral blood mononuclear cells culture (PBMC) from FOP patients and controls to determine effectiveness of the combination therapy. PBMC were treated with AA, PP and AA+PP combination. Basal expression of 12 of the 22 genes in FOP PBMC was statistically different from controls. ACVR1, ADCY2, ADCY9 and COL3 were downregulated while COL1 was upregulated. ADRB1, ADRB2, RUNX2, TNF-α and ACTB, were all overexpressed in FOP PBMC. In control, AA upregulated COL1, SVCT1, ACTB, AGTR2 and downregulated ADCY2. In FOP cells, AA upregulated ACVR1, BMP4, COL1, COL3, TNF-α, ADCY2, ADCY9, AGTR2 and MAS, while downregulated ADBR2, RUNX2, ADCY1, SVCT1 and ACTB. PP increased ADBR1 and decreased RUNX2, TNF-α, AGTR1, ACTB and CHRNA7 genes in treated control PBMC compared to untreated. PP upregulated ADBR1, ADBR2 and MAS, and downregulated TNF-α and ACTB in treated FOP PBMC versus untreated. AA+PP augmented ADRB1 and ADRB2 expressions in control PBMC. In FOP PBMC, AA+PP augmented ACVR1, COL1, COL3, ADBR1, AGTR2 and MAS expression and downregulated ADBR2, RUNX2, ACTB and MRGD. These data show distinct gene expression modulation in leukocytes from FOP patients when treated with AA and or PP.
RESUMEN
Fibrodysplasia ossificans progressiva (FOP) is a rare, intractable and devastating genetic connective tissue disorder characterized by progressive ectopic ossification in the soft tissues and skeleton. Three patients, one teenage girl (P1), one male adult (P2) and one male child (P3), were studied and treated with FOPCON (combined formulation of 14 mg of propranolol and 250 mg of ascorbic acid), given three times per day. P1 started treatment in March 2012, P2 in October 2012 and P3 in July 2015. The clinical follow-up of these three patients, before initiating treatment with FOPCON, showed that FOP flare-ups used to occur frequently and that under FOPCON therapy, none of these patients had flare-ups. The striking feature of this treatment with FOPCON, is that, all three cases suffered accidental falls with documented injures until complete healing and that where major flare-ups should occur, injures or sequels, there was none. The present clinical observation shows that ascorbic acid plus the nonspecific beta blocker propranolol can be effectively useful, when administered previously and continually, in the prophylaxis of FOP flare-ups, especially for accidental falls. In this regard, FOPCON could be a prophylactic aid in cases of surgery of patients with FOP, hoping that it may benefit patients from having the severe sequels, characteristic of heterotopic bone formation. All three patients reported, to date, they no longer had flare-ups nor heterotopic ossification and showed normal scar healing.
RESUMEN
BACKGOUND: The male-specific region of chromosome-Y (MSY) contributes to phenotypes outside of testis development and has a high rate of evolution between mammalian species. With a lack of genomic crossover, MSY is one of the few genomic areas under similar variation and evolutionary selection in inbred and outbred animal populations, allowing for an assessment of evolutionary mechanisms to translate between the populations. METHODS: Using next-generation sequencing, MSY consomic strains, molecular characterization, and large-scale phenotyping, we present here regions of MSY that contribute to inbred strain phenotypes. RESULTS: We have shown that (1) MSY of rat has nine autosomal gene transposition events with strain-specific selection; (2) sequence variants in MSY occur with a 1.98-fold higher number of variants than other chromosomes in seven sequenced rat strains; (3) Sry, the most studied MSY gene, has undergone extensive gene duplications, driving ubiquitous expression not seen in human or mouse; (4) the expression profile of Sry in the rat is driven by the insertion of the Sry2 copy into an intron of the ubiquitously expressed Kdm5d gene in antisense orientation, but due to several loss of function mutations in the Sry2 protein, nuclear localization and transcriptional control are decreased; (5) expression of Sry copies other than Sry2 in the rat overlaps with the expression profile for human SRY; (6) gene duplications and sequence variants (P76T) of Sry can be selected for phenotypes such as high blood pressure and androgen receptor signaling within inbred mating; and most importantly, (7) per chromosome size, MSY contributes to higher strain-specific phenotypic variation relative to all other chromosomes, with 53 phenotypes showing both a male to female and consomic cross significance. CONCLUSION: The data presented supports a high probability of MSY genetic variation altering a broad range of inbred rat phenotypes.
RESUMEN
The renin-angiotensin system (RAS) is subject to sex-specific modulation by hormones and gene products. However, sex differences in the balance between the vasoconstrictor/proliferative ACE/ANG II/AT1 axis, and the vasodilator/antiproliferative ACE2/ANG-(1-7)/MAS axis are poorly known. Data in the rat have suggested the male-specific Y-chromosome gene Sry to contribute to balance between these two axes, but why the testis-determining gene has these functions remains unknown. A combination of in silico genetic/protein comparisons, functional luciferase assays for promoters of the human RAS, and RNA-Seq profiling in rat were used to address if regulation of Sry on the RAS is conserved in the homologous X-chromosome gene, Sox3. Both SRY and SOX3 upregulated the promoter of Angiotensinogen (AGT) and downregulated the promoters of ACE2, AT2, and MAS, likely through overlapping mechanisms. The regulation by both SRY and SOX3 on the MAS promoter indicates a cis regulation through multiple SOX binding sites. The Renin (REN) promoter is upregulated by SRY and downregulated by SOX3, likely through trans and cis mechanisms, respectively. Sry transcripts are found in all analyzed male rat tissues including the kidney, while Sox3 transcripts are found only in the brain and testis, suggesting that the primary tissue for renin production (kidney) can only be regulated by SRY and not SOX3. These results suggest that SRY regulation of the RAS is partially shared with its X-chromosome homolog SOX3, but SRY gained a sex-specific control in the kidney for the rate-limiting step of the RAS, potentially resulting in male-specific blood pressure regulation.
Asunto(s)
Regulación de la Expresión Génica , Regiones Promotoras Genéticas , Sistema Renina-Angiotensina/genética , Factores de Transcripción SOXB1/genética , Proteína de la Región Y Determinante del Sexo/genética , Cromosoma X/genética , Cromosoma Y/genética , Secuencia de Aminoácidos , Angiotensinógeno/genética , Animales , Secuencia de Bases , Sitios de Unión , Células CHO , Secuencia Conservada , Cricetinae , Cricetulus , Femenino , Perfilación de la Expresión Génica , Humanos , Luciferasas/metabolismo , Masculino , Datos de Secuencia Molecular , Peptidil-Dipeptidasa A/genética , Renina/genética , Factores de Transcripción SOXB1/química , Factores de Transcripción SOXB1/metabolismo , Homología de Secuencia de Ácido Nucleico , Proteína de la Región Y Determinante del Sexo/química , Proteína de la Región Y Determinante del Sexo/metabolismoRESUMEN
There has been an intense research effort in the last decades in the field of biofouling prevention as it concerns many aspects of everyday life and causes problems to devices, the environment, and human health. Many different antifouling and antimicrobial materials have been developed to struggle against bacteria and other micro- and macro-organism attachment to different surfaces. However the "miracle solution" has still to be found. The research presented here concerns the synthesis of bio-based polymeric materials and the biological tests that showed their antifouling and, at the same time, antibacterial activity. The raw material used for the coating synthesis was natural rubber. The polyisoprene chains were fragmented to obtain oligomers, which had reactive chemical groups at their chain ends, therefore they could be modified to insert polymerizable and biocidal groups. Films were obtained by radical photopolymerization of the natural rubber derived oligomers and their structure was altered, in order to understand the mechanism of attachment inhibition and to increase the efficiency of the anti-biofouling action. The adhesion of three species of pathogenic bacteria and six strains of marine bacteria was studied. The coatings were able to inhibit bacterial attachment by contact, as it was verified that no detectable leaching of toxic molecules occurred.
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Antiinfecciosos/farmacología , Adhesión Bacteriana/efectos de los fármacos , Butadienos/farmacología , Hemiterpenos/farmacología , Pentanos/farmacología , Polímeros/farmacología , Antiinfecciosos/química , Adhesión Bacteriana/fisiología , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Butadienos/química , Bacterias Gramnegativas/clasificación , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Gramnegativas/fisiología , Bacterias Grampositivas/clasificación , Bacterias Grampositivas/efectos de los fármacos , Bacterias Grampositivas/fisiología , Hemiterpenos/química , Espectroscopía de Resonancia Magnética , Microscopía de Fuerza Atómica , Estructura Molecular , Pentanos/química , Polímeros/química , Agua de Mar/microbiología , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de SuperficieRESUMEN
The details of protein pathways at a structural level provides a bridge between genetics/molecular biology and physiology. The renin-angiotensin system is involved in many physiological pathways with informative structural details in multiple components. Few studies have been performed assessing structural knowledge across the system. This assessment allows use of bioinformatics tools to fill in missing structural voids. In this paper we detail known structures of the renin-angiotensin system and use computational approaches to estimate and model components that do not have their protein structures defined. With the subsequent large library of protein structures, we then created a species specific protein library for human, mouse, rat, bovine, zebrafish, and chicken for the system. The rat structural system allowed for rapid screening of genetic variants from 51 commonly used rat strains, identifying amino acid variants in angiotensinogen, ACE2, and AT1b that are in contact positions with other macromolecules. We believe the structural map will be of value for other researchers to understand their experimental data in the context of an environment for multiple proteins, providing pdb files of proteins for the renin-angiotensin system in six species. With detailed structural descriptions of each protein, it is easier to assess a species for use in translating human diseases with animal models. Additionally, as whole genome sequencing continues to decrease in cost, tools such as molecular modeling will gain use as an initial step in designing efficient hypothesis driven research, addressing potential functional outcomes of genetic variants with precompiled protein libraries aiding in rapid characterizations.
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Angiotensinógeno/química , Evolución Biológica , Biología Computacional , Modelos Moleculares , Sistema Renina-Angiotensina , Renina/química , Secuencia de Aminoácidos , Angiotensinógeno/metabolismo , Animales , Bovinos , Pollos , Humanos , Ratones , Datos de Secuencia Molecular , Conformación Proteica , Ratas , Renina/metabolismo , Homología de Secuencia de Aminoácido , Especificidad de la Especie , Pez CebraRESUMEN
Leptin is a pleiotropic protein best known for regulation of appetite and fat storage in mammals. While many leptin orthologs have been identified among vertebrates, an authentic leptin in birds has remained elusive and controversial. Here we identify leptin sequence from the Peregrine falcon, Falco peregrinus (pfleptin), and identify sequences from two other birds (mallard and zebra finch), and 'missing' vertebrates (elephant shark, alligator, Indian python, Chinese soft-shelled turtle, and coelacanth). The pattern of genes surrounding leptin (snd1, rbm28) is syntenic between the falcon and mammalian genomes. Phylogenetic analysis of all known leptin protein sequences improves our understanding of leptin's evolution. Structural modeling of leptin orthologs highlights a highly conserved hydrophobic core in the four-helix cytokine packing domain. A docked model of leptin with the leptin receptor for Peregrine falcon reveals several conserved amino acids important for the interaction and possible coevolution of leptin with its receptor. We also show for the first time, an authentic avian leptin sequence that activates the JAK-STAT signaling pathway. These newly identified sequences, structures, and tools for avian leptin and its receptor will allow elucidation of the function of these proteins in feral and domestic birds.
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Aves/genética , Evolución Molecular , Leptina , Modelos Moleculares , Filogenia , Receptores de Leptina , Animales , Leptina/química , Leptina/genética , Receptores de Leptina/química , Receptores de Leptina/genética , Reptiles/genética , Análisis de Secuencia de ProteínaRESUMEN
Lung failure due to chronic bacterial infection is the leading cause of death for patients with cystic fibrosis (CF). It is thought that the chronic nature of these infections is, in part, due to the increased tolerance and recalcitrant behaviour of bacteria growing as biofilms. Inhalation of silver carbene complex (SCC) antimicrobial, either encased in polymeric biodegradable particles or in aqueous form, has been proposed as a treatment. Through a coordinated experimental and mathematical modelling effort, we examine this proposed treatment of lung biofilms. Pseudomonas aeruginosa biofilms grown in a flow-cell apparatus irrigated with an artificial CF sputum medium are analysed as an in vitro model of CF lung infection. A 2D mathematical model of biofilm growth within the flow-cell is developed. Numerical simulations demonstrate that SCC inactivation by the environment is critical in aqueous SCC, but not SCC-polymer, based treatments. Polymer particle degradation rate is shown to be an important parameter that can be chosen optimally, based on environmental conditions and bacterial susceptibility.
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Biopelículas/crecimiento & desarrollo , Fibrosis Quística/complicaciones , Modelos Inmunológicos , Infecciones por Pseudomonas/complicaciones , Pseudomonas aeruginosa/crecimiento & desarrollo , Plata/farmacología , Biopelículas/efectos de los fármacos , Simulación por Computador , Fibrosis Quística/inmunología , Humanos , Técnicas In Vitro , Microscopía Confocal , Infecciones por Pseudomonas/tratamiento farmacológico , Infecciones por Pseudomonas/inmunología , Pseudomonas aeruginosa/ultraestructura , Plata/administración & dosificación , Esputo/microbiologíaRESUMEN
The ACE2 (angiotensin-converting enzyme 2)/Ang-(1-7) [angiotensin-(1-7)]/MAS axis of the RAS (renin-angiotensin system) has emerged as a pathway of interest in treating both cardiovascular disorders and cancer. The MAS protein is known to bind to and be activated by Ang-(1-7); however, the mechanisms of this activation are just starting to be understood. Although there are strong biochemical data regarding the regulation and activation of the AT1R (angiotensin II type 1 receptor) and the AT2R (angiotensin II type 2 receptor), with models of how AngII (angiotensin II) binds each receptor, fewer studies have characterized MAS. In the present study, we characterize the MAS promoter and provide a potential feedback mechanism that could compensate for MAS degradation following activation by Ang-(1-7). Analysis of ENCODE data for the MAS promoter revealed potential epigenetic control by KRAB (Krüppel-associated box)/KAP-1 (KRAB-associated protein-1). A proximal promoter construct for the MAS gene was repressed by the SOX [SRY (sex-determining region on the Y chromosome) box] proteins SRY, SOX2, SOX3 and SOX14, of which SRY is known to interact with the KRAB domain. The KRAB-KAP-1 complex can be tyrosine-nitrated, causing the dissociation of the KAP-1 protein and thus a potential loss of epigenetic control. Activation of MAS can lead to an increase in nitric oxide, suggesting a feedback mechanism for MAS on its own promoter. The results of the present study provide a more complete view of MAS regulation and, for the first time, suggest biochemical outcomes for nitration of the KRAB domain.
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Retroalimentación Fisiológica , Regulación de la Expresión Génica , Factores de Transcripción de Tipo Kruppel/química , Factores de Transcripción de Tipo Kruppel/metabolismo , Regiones Promotoras Genéticas , Proteínas Proto-Oncogénicas/genética , Receptores Acoplados a Proteínas G/genética , Tirosina/metabolismo , Animales , Humanos , Modelos Biológicos , Modelos Moleculares , Óxido Nítrico/metabolismo , Nitrosación , Unión Proteica/genética , Estructura Terciaria de Proteína , Proto-Oncogenes Mas , Proteína de la Región Y Determinante del SexoRESUMEN
BACKGROUND: Gene copy number variation plays a large role in the evolution of genomes. In Rattus norvegicus and other rodent species, the Y-chromosome has accumulated multiple copies of Sry loci. These copy number variations have been previously linked with changes in phenotype of animal models such as the spontaneously hypertensive rat (SHR). This study characterizes the Y-chromosome in the Sry region of Rattus norvegicus, while addressing functional variations seen in the Sry protein products. RESULTS: Eleven Sry loci have been identified in the SHR with one (nonHMG Sry) containing a frame shift mutation. The nonHMGSry is found and conserved in the related WKY and SD rat strains. Three new, previously unidentified, Sry loci were identified in this study (Sry3BII, Sry4 and Sry4A) in both SHR and WKY. Repetitive element analysis revealed numerous LINE-L1 elements at regions where conservation is lost among the Sry copies. In addition we have identified a retrotransposed copy of Med14 originating from spliced mRNA, two autosomal genes (Ccdc110 and HMGB1) and a normal mammalian Y-chromosome gene (Zfy) in the Sry region of the rat Y-chromosome. Translation of the sequences of each Sry gene reveals eight proteins with amino acid differences leading to changes in nuclear localization and promoter activation of a Sry-responsive gene. Sry-ß (coded by the Sry2 locus) has an increased cytoplasmic fraction due to alterations at amino acid 21. Sry-γ has altered gene regulation of the Sry1 promoter due to changes at amino acid 76. CONCLUSIONS: The duplication of Sry on the Rattus norvegicus Y-chromosome has led to proteins with altered functional ability that may have been selected for functions in addition to testis determination. Additionally, several other genes not normally found on the Y-chromosome have duplicated new copies into the region around the Sry genes. These suggest a role of active transposable elements in the evolution of the mammalian Y-chromosome in species such as Rattus norvegicus.
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Variaciones en el Número de Copia de ADN/genética , Proteína de la Región Y Determinante del Sexo/genética , Cromosoma Y/genética , Animales , Secuencia de Bases , Proteínas de Unión al ADN , Regulación de la Expresión Génica , Humanos , Masculino , Ratas , Ratas Endogámicas SHR , Proteína de la Región Y Determinante del Sexo/biosíntesis , Testículo/metabolismoRESUMEN
In the medical field, attached bacteria can cause infections associated with catheters, incisions, burns, and medical implants especially in immunocompromised patients. The problem is exacerbated by the fact that attached bacteria are â¼1000 times more resistant to antibiotics than planktonic cells. The rapid spread of antibiotic resistance in these and other organisms has led to a significant need to find new methods for preventing bacterial attachment. The goal of this research was to evaluate the effectiveness of novel polymer coatings to prevent the attachment of three medically relevant bacteria. Tests were conducted with Pseudomonas aeruginosa, Staphylococcus epidermidis, and Staphylococcus aureus for oligomers derived from modifications of natural rubber (cis 1,4-polyisoprene). The different oligomers were: PP04, with no quaternary ammonium (QA); MV067, one QA; PP06, three QA groups. In almost all experiments, cell attachment was inhibited to various extents as long as the oligomers were used. PP06 was the most effective as it decreased the planktonic cell numbers by at least 50% for all bacteria. Differences between species sensitivity were also observed. P. aeruginosa was the most resistant bacteria tested, S. aureus, the most sensitive. Further experiments are required to understand the full extent and mode of the antimicrobial properties of these surfaces.
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Antibacterianos/química , Antibacterianos/farmacología , Adhesión Bacteriana/efectos de los fármacos , Pseudomonas aeruginosa/efectos de los fármacos , Goma/química , Goma/farmacología , Staphylococcus/efectos de los fármacos , Hemiterpenos/química , Hemiterpenos/farmacología , Humanos , Látex/química , Látex/farmacología , Infecciones por Pseudomonas/prevención & control , Pseudomonas aeruginosa/fisiología , Infecciones Estafilocócicas/prevención & control , Staphylococcus/fisiología , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/fisiología , Staphylococcus epidermidis/efectos de los fármacos , Staphylococcus epidermidis/fisiologíaRESUMEN
The renin-angiotensin system is involved in multiple conditions ranging from cardiovascular disorders to cancer. Components of the pathway, including ACE, renin and angiotensin receptors are targets for disease treatment. This study addresses three receptors of the pathway: AT1, AT2, and MAS and how the receptors are similar and differ in activation by angiotensin peptides. Combining biochemical and amino acid variation data with multiple species sequence alignments, structural models, and docking site predictions allows for visualization of how angiotensin peptides may bind and activate the receptors; allowing identification of conserved and variant mechanisms in the receptors. MAS differs from AT1 favoring Ang-(1-7) and not Ang II binding, while AT2 recently has been suggested to preferentially bind Ang III. A new model of Ang peptide binding to AT1 and AT2 is proposed that correlates data from site directed mutagenesis and photolabled experiments that were previously considered conflicting. Ang II binds AT1 and AT2 through a conserved initial binding mode involving amino acids 111 (consensus 325) of AT1 (Asn) interacting with Tyr (4) of Ang II and 199 and 256 (consensus 512 and 621, a Lys and His respectively) interacting with Phe (8) of Ang II. In MAS these sites are not conserved, leading to differential binding and activation by Ang-(1-7). In both AT1 and AT2, the Ang II peptide may internalize through Phe (8) of Ang II propagating through the receptors' conserved aromatic amino acids to the final photolabled positioning relative to either AT1 (amino acid 294, Asn, consensus 725) or AT2 (138, Leu, consensus 336). Understanding receptor activation provides valuable information for drug design and identification of other receptors that can potentially bind Ang peptides.
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Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Proteínas Proto-Oncogénicas/química , Receptor de Angiotensina Tipo 1/química , Receptor de Angiotensina Tipo 2/química , Receptores Acoplados a Proteínas G/química , Secuencia de Aminoácidos , Angiotensina I/química , Angiotensina II/química , Angiotensina III/química , Humanos , Datos de Secuencia Molecular , Péptidos/química , Peptidil-Dipeptidasa A/química , Unión Proteica , Dominios y Motivos de Interacción de Proteínas , Transporte de Proteínas , Proto-Oncogenes Mas , Renina/química , Alineación de Secuencia , Homología Estructural de ProteínaRESUMEN
Binding of transcription factors to DNA is a dynamic process allowing for spatial- and sequence-specificity. Many methods for determination of DNA-protein structures do not allow for identification of dynamics of the search process, but provide only a single snapshot of the most stable binding. In order to better understand the dynamics of DNA binding as a protein encounters its cognate site, we have created a computer-based DNA scanning array macro that sequentially inserts a high affinity DNA consensus binding site at all possible locations in a predicted protein-DNA interface. We show, using short molecular dynamic simulations at each location in the interface, that energy minimized states and decreased movement of evolutionary conserved amino acids can be readily observed and used to predict the consensus binding site. The macro was applied to SNAIL class C2H2 zinc finger family proteins. The analysis suggests that (1) SNAIL binds to the E-box in multiple states during its encounter with its cognate site; (2) several different amino acids contribute to the E-box binding in each state; (3) the linear array of zinc fingers contributes differentially to overall folding and base-pair recognition; and (4) each finger may be specialized for stability and sequence specificity. Moreover, the macromolecular movement observed using this dynamic approach may allow the NH2-terminal finger to bind without sequence specificity yet result in higher binding energy. This macro and overall approach could be applicable to many evolutionary conserved transcription factor families and should help to better elucidate the varied mechanisms used for DNA sequence-specific binding.
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ADN/química , Elementos E-Box , Simulación de Dinámica Molecular , Factores de Transcripción/química , Secuencia de Aminoácidos , Sitios de Unión , Simulación por Computador , ADN/genética , ADN/metabolismo , Conformación Molecular , Simulación del Acoplamiento Molecular , Datos de Secuencia Molecular , Unión Proteica , Factores de Transcripción de la Familia Snail , Factores de Transcripción/metabolismo , Dedos de ZincRESUMEN
We present a mathematical model of mushroom-like architecture and cavity formation in Pseudomonas aeruginosa biofilms. We demonstrate that a proposed disparity in internal friction between the stalk and cap extracellular polymeric substances (EPS) leads to spatial variation in volumetric expansion sufficient to produce the mushroom morphology. The capability of diffusible signals to induce the formation of a fluid-filled cavity within the cap is then investigated. We assume that conversion of bacteria to the planktonic state within the cap occurs in response to the accumulation or depletion of some signal molecule. We (a) show that neither simple nutrient starvation nor signal production by one or more subpopulations of bacteria is sufficient to trigger localized cavity formation. We then (b) demonstrate various hypothetical scenarios that could result in localized cavity formation. Finally, we (c) model iron availability as a detachment signal and show simulation results demonstrating cavity formation by iron starvation. We conclude that iron availability is a plausible mechanism by which fluid-filled cavities form in the cap region of mushroom-like structures.
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Biopelículas/crecimiento & desarrollo , Deficiencias de Hierro , Modelos Biológicos , Pseudomonas aeruginosa/crecimiento & desarrollo , Pseudomonas aeruginosa/fisiología , Biopelículas/efectos de los fármacos , Simulación por Computador , Oligopéptidos/farmacología , Pseudomonas aeruginosa/efectos de los fármacos , Transducción de Señal/efectos de los fármacosRESUMEN
BACKGROUND: The DNA binding domain of HMG proteins is known to be important in many diseases, with the Sox sub-family of HMG proteins of particular significance. Numerous natural variants in HMG proteins are associated with disease phenotypes. Integrating these natural variants, molecular dynamic simulations of DNA interaction and sequence and structure alignments give detailed molecular knowledge of potential amino acid function such as DNA or protein interaction. RESULTS: A total of 33 amino acids in HMG proteins are known to have natural variants in diseases. Eight of these amino acids are normally conserved in human HMG proteins and 27 are conserved in the human Sox sub-family. Among the six non-Sox conserved amino acids, amino acids 16 and 45 are likely targets for interaction with other proteins. Docking studies between the androgen receptor and Sry/Sox9 reveals a stable amino acid specific interaction involving several Sox conserved residues. CONCLUSION: The HMG box has structural conservation between the first two of the three helixes in the domain as well as some DNA contact points. Individual sub-groups of the HMG family have specificity in the location of the third helix, DNA specific contact points (such as amino acids 4 and 29), and conserved amino acids interacting with other proteins such as androgen receptor. Studies such as this help to distinguish individual members of a much larger family of proteins and can be applied to any protein family of interest.
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Aminoácidos/química , Dominios HMG-Box , Proteínas del Grupo de Alta Movilidad/química , Simulación de Dinámica Molecular , ADN/química , ADN/metabolismo , Enfermedad/genética , Variación Genética , Proteínas del Grupo de Alta Movilidad/genética , Proteínas del Grupo de Alta Movilidad/metabolismo , Humanos , Estructura Secundaria de Proteína , Alineación de Secuencia , Análisis de Secuencia de Proteína , Homología Estructural de ProteínaRESUMEN
The testis determining protein, Sry, has functions outside of testis determination. Multiple Sry loci are found on the Y-chromosome. Proteins from these loci have differential activity on promoters of renin-angiotensin system genes, possibly contributing to elevation of blood pressure. Variation at amino acid 76 accounts for the majority of differential effects by rat proteins Sry1 and Sry3. Human SRY regulated rat promoters in the same manner as rat Sry, elevating Agt, Ren, and Ace promoter activity while downregulating Ace 2. Human SRY significantly regulated human promoters of AGT, REN, ACE2, AT2, and MAS compared to control levels, elevating AGT and REN promoter activity while decreasing ACE2, AT2, and MAS. While the effect of human SRY on individual genes is often modest, we show that many different genes participating in the renin-angiotensin system can be affected by SRY, apparently in coordinated fashion, to produce more Ang II and less Ang-(1-7).
RESUMEN
Apoptosis can be induced or inhibited by viral proteins, it can form part of the host defense against virus infection, or it can be a mechanism for viral spread to neighboring cells. Canine distemper virus (CDV) induces apoptotic cells in lymphoid tissues and in the cerebellum of dogs naturally infected. CDV also produces a cytopathologic effect, leading to apoptosis in Vero cells in tissue culture. We tested canine distemper virus, a member of the Paramyxoviridae family, for the ability to trigger apoptosis in HeLa cells, derived from cervical cancer cells resistant to apoptosis. To study the effect of CDV infection in HeLa cells, we examined apoptotic markers 24 h post infection (pi), by flow cytometry assay for DNA fragmentation, real-time PCR assay for caspase-3 and caspase-8 mRNA expression, and by caspase-3 and -8 immunocytochemistry. Flow cytometry showed that DNA fragmentation was induced in HeLa cells infected by CDV, and immunocytochemistry revealed a significant increase in the levels of the cleaved active form of caspase-3 protein, but did not show any difference in expression of caspase-8, indicating an intrinsic apoptotic pathway. Confirming this observation, expression of caspase-3 mRNA was higher in CDV infected HeLa cells than control cells; however, there was no statistically significant change in caspase-8 mRNA expression profile. Our data suggest that canine distemper virus induced apoptosis in HeLa cells, triggering apoptosis by the intrinsic pathway, with no participation of the initiator caspase -8 from the extrinsic pathway. In conclusion, the cellular stress caused by CDV infection of HeLa cells, leading to apoptosis, can be used as a tool in future research for cervical cancer treatment and control.
Asunto(s)
Apoptosis , Virus del Moquillo Canino/patogenicidad , Virus Oncolíticos/patogenicidad , Caspasa 3/biosíntesis , Caspasa 8/biosíntesis , Fragmentación del ADN , Citometría de Flujo , Perfilación de la Expresión Génica , Células HeLa , Humanos , InmunohistoquímicaRESUMEN
The Sry locus on the mammalian Y chromosome is the developmental switch responsible for testis determination. Inconsistent with this important function, the Sry locus is transcribed in adult males at times and in tissues not involved with testis determination. Sry is expressed in multiple tissues of the peripheral and central nervous system. Sry is derived from Sox3 and is similar to other SOXB family loci. The SOXB loci are responsible for nervous system development. Sry has been demonstrated to modulate the catecholamine pathway, so it should have functional consequences in the central and peripheral nervous system. The nervous system expression and potential function are consistent with Sry as a SOXB family member. In mammals, Sox3 is X-linked and undergoes dosage compensation in females. The expression of Sry in adult males allows for a type of sexual differentiation independent of circulating gonadal hormones. A quantitative difference in Sox3 plus Sry expression in males vs. females could drive changes in the transcriptome of these cells, differentiating male and female cells. Sry expression and its transcriptional effects should be considered when investigating sexual dimorphic phenotypes.
Asunto(s)
Proteína de la Región Y Determinante del Sexo/metabolismo , Transducción de Señal , Testículo/metabolismo , Cromosoma Y , Animales , Femenino , Regulación de la Expresión Génica , Genotipo , Humanos , Masculino , Sistema Nervioso/metabolismo , Sistemas Neurosecretores/metabolismo , Organogénesis , Fenotipo , Conformación Proteica , Factores de Transcripción SOXB1/genética , Factores de Transcripción SOXB1/metabolismo , Caracteres Sexuales , Procesos de Determinación del Sexo , Proteína de la Región Y Determinante del Sexo/química , Proteína de la Región Y Determinante del Sexo/genética , Testículo/embriologíaRESUMEN
BACKGROUND: Sex-determining region Y (Sry) is a transcription factor. Our research group has shown that there are multiple copies of Sry in Wistar-Kyoto (WKY) and spontaneous hypertensive (SHR) rats, and that they have novel functions separate from testes determination. OBJECTIVE: We hypothesized that exogenously delivered Sry3 to the normotensive WKY male kidney would activate the renin-angiotensin system (RAS) and raise blood pressure (BP), based on previous in vitro studies. METHODS: Sry3 or control vector was electroporated to the left kidney of male WKY rats and the following measurements were taken: BP by telemetry, renin-angiotensin measures by radioimmunoassay, plasma and tissue catecholamines by HPLC with electrochemical detection, sodium by flame photometry, and inulin by ELISA. RESULTS: Sry3 increased BP 10 to 20 mm Hg compared with controls (P < 0.01) and produced a significant 40% decrease in urine sodium compared with controls (P < 0.05). Sry3 increased renal angiotensin II and plasma renin activity by >100% compared with controls (P < 0.01 and P < 0.05, respectively). CONCLUSION: The findings presented here confirm and extend the argument for Sry3 as one of the genes responsible for the SHR hypertensive Y chromosome phenotype and are consistent with increased tissue RAS activity due to Sry3 and increased sodium reabsorption.