In vitro nuclear interactome of the HIV-1 Tat protein

<p>Abstract</p> <p>Background</p> <p>One facet of the complexity underlying the biology of HIV-1 resides not only in its limited number of viral proteins, but in the extensive repertoire of cellular proteins they interact with and their higher-order assembly. HIV-1 encodes the regulatory protein Tat (86–101aa), which is essential for HIV-1 replication and primarily orchestrates HIV-1 provirus transcriptional regulation. Previous studies have demonstrated that Tat function is highly dependent on specific interactions with a range of cellular proteins. However they can only partially account for the intricate molecular mechanisms underlying the dynamics of proviral gene expression. To obtain a comprehensive nuclear interaction map of Tat in T-cells, we have designed a proteomic strategy based on affinity chromatography coupled with mass spectrometry.</p> <p>Results</p> <p>Our approach resulted in the identification of a total of 183 candidates as Tat nuclear partners, 90% of which have not been previously characterised. Subsequently we applied <it>in silico </it>analysis, to validate and characterise our dataset which revealed that the Tat nuclear interactome exhibits unique signature(s). First, motif composition analysis highlighted that our dataset is enriched for domains mediating protein, RNA and DNA interactions, and helicase and ATPase activities. Secondly, functional classification and network reconstruction clearly depicted Tat as a polyvalent protein adaptor and positioned Tat at the nexus of a densely interconnected interaction network involved in a range of biological processes which included gene expression regulation, RNA biogenesis, chromatin structure, chromosome organisation, DNA replication and nuclear architecture.</p> <p>Conclusion</p> <p>We have completed the <it>in vitro </it>Tat nuclear interactome and have highlighted its modular network properties and particularly those involved in the coordination of gene expression by Tat. Ultimately, the highly specialised set of molecular interactions identified will provide a framework to further advance our understanding of the mechanisms of HIV-1 proviral gene silencing and activation.</p

Rapid identification of causal mutations in tomato EMS populations via mapping-by-sequencing

The tomato is the model species of choice for fleshy fruit development and for the Solanaceae family. Ethyl methanesulfonate (EMS) mutants of tomato have already proven their utility for analysis of gene function in plants, leading to improved breeding stocks and superior tomato varieties. However, until recently, the identification of causal mutations that underlie particular phenotypes has been a very lengthy task that many laboratories could not afford because of spatial and technical limitations. Here, we describe a simple protocol for identifying causal mutations in tomato using a mapping-by-sequencing strategy. Plants displaying phenotypes of interest are first isolated by screening an EMS mutant collection generated in the miniature cultivar Micro-Tom. A recombinant F2 population is then produced by crossing the mutant with a wild-type (WT; non-mutagenized) genotype, and F2 segregants displaying the same phenotype are subsequently pooled. Finally, whole-genome sequencing and analysis of allele distributions in the pools allow for the identification of the causal mutation. The whole process, from the isolation of the tomato mutant to the identification of the causal mutation, takes 6-12 months. This strategy overcomes many previous limitations, is simple to use and can be applied in most laboratories with limited facilities for plant culture and genotyping

Description par vidéomicroscopie des évènements du cycle intra-érythrocytaire de Babesia divergens

MONTPELLIER-BU Pharmacie (341722105) / SudocSudocFranceF

Tomato resources for functional genomics

Tomato is currently the model species for fleshy fruit development and for Solanaceae species. The recent completion of a high‐quality genome sequence of the inbred tomato (Solanum lycopersicum) cultivar ‘Heinz 1706’ allowed the prediction and in silico annotation of ca 35,000 genes. Assigning a biological function to these genes is among the priorities of the tomato community, especially for genes contributing to fleshy fruit development and quality, and to other major agronomical traits in tomato and Solanaceae. More than a decade of research using genomic tools, mostly transcriptome and metabolome, combined with genetic mapping approaches, provided first cues on the possible function of tomato genes by describing where, when, and with which other gene/metabolite these genes are expressed. Current advances in sequencing technologies now allow the exhaustive inventory of tomato transcripts in various plant organs, tissues and even cell types. To cope with the need to assign biological functions to a large number of genes, tomato mutant resources based on several technologies [T‐DNA and transposon insertional mutants, fast‐neutron, γ‐ray and ethyl methanesulfonate (EMS) mutants] have been developed in the recent years. Among them, the Targeting Induced Local Lesions In Genomes (TILLING) technology, based on the generation by EMS of high density point mutations evenly distributed in the genome and on the subsequent detection of mutations in target genes is presently the most established. The present chapter will describe the main resources, strategies and tools currently available for linking genes to phenotype in tomato

Cholangiocarcinoma occurring in a patient with type 1 Gaucher disease treated with velaglucerase alfa enzyme replacement therapy: First case report

International audienc

Parkinsonian Patients Requiring Proteasome Inhibitors for Multiple Myeloma: Exceptional Circumstances Call for Extra Caution

Feedback on the management of patients with both Parkinson’s disease (PD) and multiple myeloma (MM) is not common in the literature, and we would like to report an original possible adverse event (AE) of MM chemotherapy: an increased PD severity induced by ixazomib. The patient, a 68-year-old man with PD (Hoehn and Yahr (HY) stage 3) was effectively and stably treated for 14 years with dopaminergic therapy (levodopa equiva25 lent daily dose (LEDD) 1275 mg). His symptomatic MM was first treated by lenalidomide (25 mg) with dexamethasone (Rd protocol) for 19 months. Then, a second-line therapy combined the proteasome inhibitor (PI) ixazomib (4 mg) with lenalidomide (20 mg) and dexamethasone (IRd protocol, 4-week cycle) due to MM progression

Tomato fruit locular tissue differentiation is regulated by a C2H2 transcription factor

International audienc

Towards the identification of genes controlling major traits in tomato through sequencing of Micro-Tom EMS mutants

National audienc