RESUMO
Intracellular trafficking plays a critical role in the functioning of highly polarized cells, such as neurons. Transport of mRNAs, proteins, and other molecules to synaptic terminals maintains contact between neurons and ensures the transmission of nerve impulses. Cytoplasmic polyadenylation element binding (CPEB) proteins play an essential role in long-term memory (LTM) formation by regulating local translation in synapses. Here, we show that the 3'UTR of the Drosophila CPEB gene orb2 is required for targeting the orb2 mRNA and protein to synapses and that this localization is important for LTM formation. When the orb2 3'UTR is deleted, the orb2 mRNAs and proteins fail to localize in synaptic fractions, and pronounced LTM deficits arise. We found that the phenotypic effects of the orb2 3'UTR deletion were rescued by introducing the 3'UTR from the orb, another Drosophila CPEB gene. In contrast, the phenotypic effects of the 3'UTR deletion were not rescued by the 3'UTR from one of the Drosophila α-tubulin genes. Our results show that the orb2 mRNAs must be targeted to the correct locations in neurons and that proper targeting depends upon sequences in the 3'UTR.
Assuntos
Proteínas de Transporte , Proteínas de Drosophila , Animais , Proteínas de Transporte/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Regiões 3' não Traduzidas/genética , Fatores de Poliadenilação e Clivagem de mRNA/genética , Fatores de Poliadenilação e Clivagem de mRNA/metabolismo , Poliadenilação/genética , Drosophila/genética , Drosophila/metabolismo , Neurônios/metabolismoRESUMO
Contribution of UCP1 single nucleotide polymorphisms (SNPs) to susceptibility for cardiometabolic pathologies (CMP) and their involvement in specific risk factors for these conditions varies across populations. We tested whether UCP1 SNPs A-3826G, A-1766G, Ala64Thr and A-112C are associated with common CMP and their risk factors across Armenia, Greece, Poland, Russia and United Kingdom. This case-control study included genotyping of these SNPs, from 2,283 Caucasians. Results were extended via systematic review and meta-analysis. In Armenia, GA genotype and A allele of Ala64Thr displayed ~2-fold higher risk for CMP compared to GG genotype and G allele, respectively (p<0.05). In Greece, A allele of Ala64Thr decreased risk of CMP by 39%. Healthy individuals with A-3826G GG genotype and carriers of mutant allele of A-112C and Ala64Thr had higher body mass index compared to those carrying other alleles. In healthy Polish, higher waist-to-hip ratio (WHR) was observed in heterozygotes A-3826G compared to AA homozygotes. Heterozygosity of A-112C and Ala64Thr SNPs was related to lower WHR in CMP individuals compared to wild type homozygotes (p<0.05). Meta-analysis showed no statistically significant odds-ratios across our SNPs (p>0.05). Concluding, the studied SNPs could be associated with the most common CMP and their risk factors in some populations.
Assuntos
Doenças Cardiovasculares , Doenças Metabólicas , Polimorfismo de Nucleotídeo Único , Proteína Desacopladora 1 , Doenças Cardiovasculares/genética , Estudos de Casos e Controles , Monofosfato de Citidina , Predisposição Genética para Doença , Humanos , Doenças Metabólicas/genética , Prevalência , Proteína Desacopladora 1/genéticaRESUMO
Components of the translation apparatus, including ribosomal proteins, have been found in cell nuclei in various organisms. Components of the translation apparatus are involved in various nuclear processes, particularly those associated with genome integrity control and the nuclear stages of gene expression, such as transcription, mRNA processing, and mRNA export. Components of the translation apparatus control intranuclear trafficking; the nuclear import and export of RNA and proteins; and regulate the activity, stability, and functional recruitment of nuclear proteins. The nuclear translocation of these components is often involved in the cell response to stimulation and stress, in addition to playing critical roles in oncogenesis and viral infection. Many components of the translation apparatus are moonlighting proteins, involved in integral cell stress response and coupling of gene expression subprocesses. Thus, this phenomenon represents a significant interest for both basic and applied molecular biology. Here, we provide an overview of the current data regarding the molecular functions of translation factors and ribosomal proteins in the cell nucleus.
Assuntos
Núcleo Celular/metabolismo , Células Eucarióticas/metabolismo , Biossíntese de Proteínas , Animais , Carcinogênese/metabolismo , Carcinogênese/patologia , Regulação da Expressão Gênica , Humanos , RNA Mensageiro/genética , RNA Mensageiro/metabolismoRESUMO
The chromatin remodeler SWI/SNF is an important participant in gene activation, functioning predominantly by opening the chromatin structure on promoters and enhancers. Here, we describe its novel mode of action in which SWI/SNF factors mediate the targeted action of an enhancer. We studied the functions of two signature subunits of PBAP subfamily, BAP170 and SAYP, in Drosophila. These subunits were stably tethered to a transgene reporter carrying the hsp70 core promoter. The tethered subunits mediate transcription of the reporter in a pattern that is generated by enhancers close to the insertion site in multiple loci throughout the genome. Both tethered SAYP and BAP170 recruit the whole PBAP complex to the reporter promoter. However, we found that BAP170-dependent transcription is more resistant to the depletion of other PBAP subunits, suggesting that BAP170 may play a more critical role in establishing enhancer-dependent transcription.
Assuntos
Montagem e Desmontagem da Cromatina/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Elementos Facilitadores Genéticos/genética , Fatores de Transcrição/genética , Transcrição Gênica , Animais , Animais Geneticamente Modificados , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Técnica Indireta de Fluorescência para Anticorpo/métodos , Humanos , Hibridização In Situ/métodos , Modelos Genéticos , Regiões Promotoras Genéticas/genética , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , Fatores de Transcrição/metabolismo , Ativação TranscricionalRESUMO
The hereditary aspect of obesity is a major focus of modern medical genetics. The genetic background is known to determine a higher-than-average prevalence of obesity in certain regions, like Oceania. There is evidence that dysfunction of brown adipose tissue (BAT) may be a risk factor for obesity and type 2 diabetes (T2D). A significant number of studies in the field focus on the UCP family. The Ucp genes code for electron transport carriers. UCP1 (thermogenin) is the most abundant protein of the UCP superfamily and is expressed in BAT, contributing to its capability of generating heat. Single nucleotide polymorphisms (SNPs) of Ucp1-Ucp3 were recently associated with risk of cardiometabolic diseases. This review covers the main Ucp SNPs A-3826G, A-1766G, A-112C, Met229Leu, Ala64Thr (Ucp1), Ala55Val, G-866A (Ucp2), and C-55 T (Ucp3), which may be associated with the development of obesity, disturbance in lipid metabolism, T2D, and cardiovascular diseases.
Assuntos
Predisposição Genética para Doença , Síndrome Metabólica/etiologia , Proteínas de Desacoplamento Mitocondrial/genética , Família Multigênica , Polimorfismo de Nucleotídeo Único , Alelos , Regulação da Expressão Gênica , Frequência do Gene , Estudos de Associação Genética , Loci Gênicos , Genótipo , Humanos , Síndrome Metabólica/diagnóstico , Síndrome Metabólica/metabolismo , Síndrome Metabólica/terapia , Especificidade de ÓrgãosRESUMO
Early stages of transcription from eukaryotic promoters include two principal events: the capping of newly synthesized mRNA and the transition of RNA polymerase II from the preinitiation complex to the productive elongation state. The capping checkpoint model implies that these events are tightly coupled, which is necessary for ensuring the proper capping of newly synthesized mRNA. Recent findings also show that the capping machinery has a wider effect on transcription and the entire gene expression process. The molecular basis of these phenomena is discussed.
Assuntos
Modelos Genéticos , Capuzes de RNA/biossíntese , RNA Polimerase II/metabolismo , RNA Mensageiro/biossíntese , Transcrição Gênica , Animais , Regulação da Expressão Gênica , Humanos , Regiões Promotoras Genéticas , Capuzes de RNA/genética , RNA Mensageiro/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
The Paip2 protein is a factor regulating mRNA translation and stability in the cytoplasm. It has also been found in the nuclei of several cell types in Drosophila. Here, we aim to elucidate the functions of Paip2 in the cell nucleus. We find that nuclear Paip2 is a component of an ~300-kDa protein complex. Paip2 interacts with mRNA capping factor and factors of RNA polymerase II (Pol II) transcription initiation and early elongation. Paip2 functionally cooperates with the Cbp80 subunit of the cap-binding complex, with both proteins ensuring proper Pol II C-terminal domain (CTD) Ser5 phosphorylation at the promoter. Thus, Paip2 is a novel player at the stage of mRNA capping and early Pol II elongation.
Assuntos
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Complexo Proteico Nuclear de Ligação ao Cap/metabolismo , Proteínas de Ligação a Poli(A)/metabolismo , Regiões Promotoras Genéticas , RNA Polimerase II/metabolismo , Animais , Linhagem Celular , DNA/metabolismo , Drosophila melanogaster/genética , Regulação da Expressão Gênica , Fosforilação , Processamento de Proteína Pós-TraducionalRESUMO
Paip2 (Poly(A)-binding protein - interacting protein 2) is a conserved metazoan-specific protein that has been implicated in regulating the translation and stability of mRNAs. However, we have found that Paip2 is not restricted to the cytoplasm but is also found in the nucleus in Drosophila embryos, salivary glands, testes, and tissue culture cells. Nuclear Paip2 is associated with chromatin, and in chromatin immunoprecipitation experiments it maps to the promoter regions of active genes. However, this chromatin association is indirect, as it is RNA-dependent. Thus, Paip2 is one more item in the growing list of translation factors that are recruited to mRNAs co-transcriptionally.