RESUMO
This chapter introduces the FastPCR software as an integrated tool environment for PCR primer and probe design, which predicts properties of oligonucleotides based on experimental studies of the PCR efficiency. The software provides comprehensive facilities for designing primers for most PCR applications and their combinations. These include the standard PCR as well as the multiplex, long-distance, inverse, real-time, group-specific, unique, overlap extension PCR for multi-fragments assembling cloning and loop-mediated isothermal amplification (LAMP). It also contains a built-in program to design oligonucleotide sets both for long sequence assembly by ligase chain reaction and for design of amplicons that tile across a region(s) of interest. The software calculates the melting temperature for the standard and degenerate oligonucleotides including locked nucleic acid (LNA) and other modifications. It also provides analyses for a set of primers with the prediction of oligonucleotide properties, dimer and G/C-quadruplex detection, linguistic complexity as well as a primer dilution and resuspension calculator. The program consists of various bioinformatical tools for analysis of sequences with the GC or AT skew, CG% and GA% content, and the purine-pyrimidine skew. It also analyzes the linguistic sequence complexity and performs generation of random DNA sequence as well as restriction endonucleases analysis. The program allows to find or create restriction enzyme recognition sites for coding sequences and supports the clustering of sequences. It performs efficient and complete detection of various repeat types with visual display. The FastPCR software allows the sequence file batch processing that is essential for automation. The program is available for download at http://primerdigital.com/fastpcr.html , and its online version is located at http://primerdigital.com/tools/pcr.html .
Assuntos
Técnicas de Amplificação de Ácido Nucleico/métodos , Oligonucleotídeos/genética , Reação em Cadeia da Polimerase/métodos , Software , Primers do DNA/genética , InternetRESUMO
Mitochondrial dysfunction has been linked to several neurodegenerative diseases such as Parkinson's disease (PD). Peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) is a master gene for mitochondrial biogenesis and has been shown to be neuroprotective in models of PD. In this work we have studied the mechanisms by which peroxisome proliferator-activated receptor-γ (PPARγ) selective agonist N-(2-benzoylphenyl)-O-[2-(methyl-2-pyridinylamino)ethyl]-l-tyrosine hydrate (GW1929) acts on human dopaminergic neurons in culture. Data showed that GW1929 increased the viability of human dopaminergic neurons and protected them against oxidative stress induced by H2O2 and the mitochondrial toxin Rotenone. The enhanced resilience of the neurons was attributed to increased levels of mitochondrial antioxidants and of PGC-1α. GW1929 treatment further increased cell respiration, mitochondrial biogenesis and sirtuin-1 (SIRT1) expression in the human dopaminergic neurons. Phosphorylation of cAMP responsive element-binding protein (CREB) was also robustly increased in GW1929-treated cells. Together these results show that the PPARγ agonist GW1929 influences CREB signaling and PGC-1α activities in the human dopaminergic neurons contributing to an increased cell viability. This supports the view that drugs acting on the PPARγ-PGC-1α signaling in neurons may have beneficial effects in PD and possible also in other brain disorders.
Assuntos
Benzofenonas/farmacologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Neurônios Dopaminérgicos/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , PPAR gama/agonistas , Fatores de Transcrição/metabolismo , Tirosina/análogos & derivados , Linhagem Celular , Neurônios Dopaminérgicos/metabolismo , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Biogênese de Organelas , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Fosforilação/efeitos dos fármacos , Sirtuína 1/metabolismo , Tirosina/farmacologiaRESUMO
Mitochondrial dysfunctions accompany several neurodegenerative disorders and contribute to disease pathogenesis among others in Parkinson's disease (PD). Peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) is a major regulator of mitochondrial functions and biogenesis, and was suggested as a therapeutic target in PD. PGC-1α is regulated by both transcriptional and posttranslational events involving also the action of growth factors. Fibroblast growth factor-21 (FGF21) is a regulator of glucose and fatty acid metabolism in the body but little is known about its action in the brain. We show here that FGF21 increased the levels and activity of PGC-1α and elevated mitochondrial antioxidants in human dopaminergic cells in culture. The activation of PGC-1α by FGF21 occurred via the NAD(+)-dependent deacetylase Sirtuin-1 (SIRT1) subsequent to an increase in the enzyme, nicotinamide phosphoribosyltransferase (Nampt). FGF21 also enhanced mitochondrial respiratory capacity in human dopaminergic neurons as shown in real-time analyses of living cells. FGF21 is present in the brain including midbrain and is expressed by glial cells in culture. These results show that FGF21 activates PGC-1α and increases mitochondrial efficacy in human dopaminergic neurons suggesting that FGF21 could potentially play a role in dopaminergic neuron viability and in PD.
RESUMO
The LDLR is a critical factor in the regulation of blood cholesterol levels that are altered in different human diseases. The level of LDLR in the cell is regulated by both transcriptional and post-transcriptional events. The E3 ubiquitin ligase, myosin regulatory light chain-interacting protein (Mylip)/inducible degrader of the LDL-R (Idol) was shown to induce degradation of LDLR via protein ubiquitination. We have here studied novel factors and mechanisms that may regulate Mylip/Idol in human hepatocyte cells and in mouse macrophages. We observed that FGF21 that is present in serum in different conditions reduced Mylip/Idol at the RNA and protein level, and increased LDLR levels and stability in the cells. FGF21 also enhanced expression of Canopy2 (Cnpy2)/MIR-interacting Saposin-like protein (Msap) that is known to interact with Mylip/Idol. Overexpression of Cnpy2/Msap increased LDLRs, and knockdown experiments showed that Cnpy2/Msap is crucial for the FGF21 effect on LDLRs. Experiments using DiI-labeled LDL particles showed that FGF21 increased lipoprotein uptake and the effect of FGF21 was additive to that of statins. Our results are consistent with an important role of FGF21 and Cnpy2/Msap in the regulation of LDLRs in cultured cells, which warrants further studies using human samples.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Colesterol/farmacocinética , Fatores de Crescimento de Fibroblastos/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Membrana/metabolismo , Receptores de LDL/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Linhagem Celular , Hepatócitos/citologia , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular/genética , Metabolismo dos Lipídeos/efeitos dos fármacos , Metabolismo dos Lipídeos/fisiologia , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Proteínas de Membrana/genética , Camundongos , Ubiquitina-Proteína Ligases/genética , Ubiquitinação/fisiologia , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/fisiologiaRESUMO
Mitochondrial dysfunction and oxidative stress occur in Parkinson's disease (PD), but little is known about the molecular mechanisms controlling these events. Peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α) is a transcriptional coactivator that is a master regulator of oxidative stress and mitochondrial metabolism. We show here that transgenic mice overexpressing PGC-1α in dopaminergic neurons are resistant against cell degeneration induced by the neurotoxin MPTP. The increase in neuronal viability was accompanied by elevated levels of mitochondrial antioxidants SOD2 and Trx2 in the substantia nigra of transgenic mice. PGC-1α overexpression also protected against MPTP-induced striatal loss of dopamine, and mitochondria from PGC-1α transgenic mice showed an increased respiratory control ratio compared with wild-type animals. To modulate PGC-1α, we employed the small molecular compound, resveratrol (RSV) that protected dopaminergic neurons against the MPTP-induced cell degeneration almost to the same extent as after PGC-1α overexpression. As studied in vitro, RSV activated PGC-1α in dopaminergic SN4741 cells via the deacetylase SIRT1, and enhanced PGC-1α gene transcription with increases in SOD2 and Trx2. Taken together, the results reveal an important function of PGC-1α in dopaminergic neurons to combat oxidative stress and increase neuronal viability. RSV and other compounds acting via SIRT1/PGC-1α may prove useful as neuroprotective agents in PD and possibly in other neurological disorders.
Assuntos
Doença de Parkinson Secundária/metabolismo , Doença de Parkinson/metabolismo , Transativadores/metabolismo , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina , Animais , Encéfalo/metabolismo , Linhagem Celular , Modelos Animais de Doenças , Feminino , Masculino , Camundongos , Camundongos Transgênicos , Mitocôndrias/metabolismo , Estresse Oxidativo , Doença de Parkinson/genética , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Transativadores/genética , Fatores de TranscriçãoRESUMO
The relevance of serine 5 phosphorylation of RNA polymerase II carboxy-terminal domain during initiation has been difficult to determine in mammalian cells as no general in vivo Ser5 kinase has been identified. Here, we demonstrate that deletion of the TFIIH kinase subunit Mat1 in mouse fibroblasts leads to dramatically reduced Pol II Ser5 phosphorylation. This is associated with defective capping and reduced Ser2 phosphorylation, decreased Pol II progression into elongation and severely attenuated transcription detected through analysis of nascent mRNAs, establishing a general requirement for mammalian Mat1 in transcription. Surprisingly, the general defect in Pol II transcription in Mat1(-/-) fibroblasts is not reflected in the majority of steady-state mRNAs. This indicates widespread stabilization of mRNAs and points to the existence of a regulatory mechanism to stabilize mRNAs following transcriptional attenuation, thus revealing a potential caveat in similar studies limited to analysis of steady-state mRNAs.
Assuntos
Sistemas de Transporte de Aminoácidos Neutros/fisiologia , RNA Polimerase II/metabolismo , RNA Mensageiro/metabolismo , Serina/metabolismo , Transcrição Gênica , Sistemas de Transporte de Aminoácidos Neutros/genética , Animais , Proteínas de Ciclo Celular , Fibroblastos/metabolismo , Deleção de Genes , Proteínas de Choque Térmico HSP70/biossíntese , Proteínas de Choque Térmico HSP70/genética , Camundongos , Fosforilação , Proteínas Quinases/química , Estrutura Terciária de Proteína , Subunidades Proteicas/genética , Subunidades Proteicas/fisiologia , Proteínas Proto-Oncogênicas c-fos/biossíntese , Proteínas Proto-Oncogênicas c-fos/genética , Capuzes de RNA/análise , RNA Polimerase II/química , Splicing de RNA , Estabilidade de RNA , RNA Mensageiro/biossíntese , Fator de Transcrição TFIIH/metabolismo , Fatores de TranscriçãoRESUMO
We report on the essential Drosophila mRpL55 gene conserved exclusively in metazoans. Null mRpL55 mutants did not grow after hatching, moved slowly and died as first instar larvae. MrpL55 is similar to mammalian MRPL55, a protein that, in a large-scale mass spectrometry study, has been found as a mitoribosome-specific large subunit protein. We showed that MrpL55 was localised to the mitochondrion in S2 cells and tissues and was enriched in cells with a higher protein synthesis activity. The MrpL55 protein contains a KOW-like motif present in proteins with a role in transcriptional anti-termination and regulation of translation. Modulation of mRpL55 expression level is critical for development. Somatic clonal analysis showed that MrpL55 was not required in larval eye imaginal discs but required in pupal discs apparently during the second mitotic wave. Therefore, our results showed that the MrpL55 protein acts dynamically in the cell during development. We propose that MrpL55 is involved in Drosophila mitochondrial biogenesis and G2/M phase cell cycle progression.
Assuntos
Proteínas de Drosophila/fisiologia , Drosophila melanogaster/crescimento & desenvolvimento , Proteínas de Ligação a RNA/fisiologia , Motivos de Aminoácidos/genética , Sequência de Aminoácidos , Animais , Animais Geneticamente Modificados , Linhagem Celular , Clonagem Molecular , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/embriologia , Drosophila melanogaster/fisiologia , Olho/citologia , Olho/crescimento & desenvolvimento , Feminino , Deleção de Genes , Expressão Gênica/genética , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Imuno-Histoquímica , Larva/genética , Larva/crescimento & desenvolvimento , Mitocôndrias/química , Mitocôndrias/metabolismo , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Proteínas Mitocondriais/fisiologia , Dados de Sequência Molecular , Mutação , Nematoides/genética , Oogênese/fisiologia , Fenótipo , Estrutura Secundária de Proteína , RNA Mensageiro Estocado/análise , RNA Mensageiro Estocado/fisiologia , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Recombinação Genética/genética , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Proteínas Ribossômicas/fisiologia , Glândulas Salivares/citologia , Glândulas Salivares/metabolismo , Homologia de Sequência de Aminoácidos , Frações Subcelulares/químicaRESUMO
RNA interference (RNAi) is mediated by a multicomponent RNA-induced silencing complex (RISC). Here we examine the phosphorylation state of three Drosophila RISC-associated proteins, VIG, R2D2 and a truncated form of Argonaute2 devoid of the nonconserved N-terminal glutamine-rich domain. We show that of the three studied proteins, only VIG is phosphorylated in cultured Drosophila cells. We also demonstrate that the phosphorylation state of VIG remains unchanged after cell transfection with exogenous dsRNA. A sequence similarity search revealed that VIG shares significant similarity with the human phosphoprotein Ki-1/57, a known in vivo substrate for protein kinase C (PKC). In vitro kinase assays followed by tryptic phosphopeptide mapping showed that PKC could efficiently phosphorylate VIG on multiple sites, suggesting PKC as a candidate kinase for VIG phosphorylation in vivo. Taken together, our results identify the RISC component VIG as a novel kinase substrate in cultured Drosophila cells and suggest a possible involvement of PKC in its phosphorylation.