Search results for "COMPARTMENT"

2017

Reconstructing the transition from a single compartment bacterium to a highly compartmentalized eukaryotic cell is one of the most studied problems of evolutionary cell biology. However, timing and details of the establishment of compartmentalization are unclear and difficult to assess. Here, we propose the use of molecular markers specific to cellular compartments to set up a framework to advance the understanding of this complex intracellular process. Specifically, we use a protein family related to ribosome biogenesis, YRG (YlqF related GTPases), whose evolution is linked to the establishment of cellular compartments, leveraging the current genomic data. We analyzed orthologous proteins …

T-Box Genes in Drosophila Limb Development

2017

T-box genes are essential for limb development in vertebrates and arthropods. The Drosophila genome encodes eight T-box genes, six of which are expressed in limb ontogenesis. The Tbx20-related gene pair midline and H15 is essential for dorso-ventral patterning of the Drosophila legs. The three Tbx6-related Dorsocross genes are required for epithelial remodeling during wing development. The Drosophila gene optomotor-blind (omb) is the only member of the Tbx2 subfamily in the fly and is predominantly involved in wing development. Omb is essential for wing development and is sufficient to promote the development of a second wing pair. Targeted manipulations of omb expression have shown that th…

Molecular partners of hNOT/ALG3, the human counterpart of the Drosophila NOT and yeast ALG3 gene, suggest its involvement in distinct cellular proces…

2018

This study provides first insights into the involvement of hNOT/ALG3, the human counterpart of the Drosophila Neighbour of TID and yeast ALG3 gene, in various putative molecular networks. HNOT/ALG3 encodes two translated transcripts encoding precursor proteins differing in their N-terminus and showing 33% identity with the yeast asparagine-linked glycosylation 3 (ALG3) protein. Experimental evidence for the functional homology of the proteins of fly and man in the N-glycosylation has still to be provided. In this study, using the yeast two-hybrid technique we identify 17 molecular partners of hNOT-1/ALG3-1. We disclose the building of hNOT/ALG3 homodimers and provide experimental evidence f…

2018

The IgMi mouse fails to secrete antibodies or class switch its BCR from IgM. Our study reveals that other cellular compartments, including B-cell subsets, DC subsets, GC B cells and TFH cells are perturbed in the IgMi mouse, thus presenting important additional considerations when using the mouse to explore the role of secreted antibody.

Encapsulation mechanisms and structural studies of GRM2 bacterial microcompartment particles

2019

Bacterial microcompartments (BMCs) are prokaryotic organelles consisting of a protein shell and an encapsulated enzymatic core. BMCs are involved in several biochemical processes, such as choline, glycerol and ethanolamine degradation and carbon fixation. Since non-native enzymes can also be encapsulated in BMCs, an improved understanding of BMC shell assembly and encapsulation processes could be useful for synthetic biology applications. Here we report the isolation and recombinant expression of BMC structural genes from the Klebsiella pneumoniae GRM2 locus, the investigation of mechanisms behind encapsulation of the core enzymes, and the characterization of shell particles by cryo-EM. We …

Analysis of the immune microenvironment in resected non-small cell lung cancer: the prognostic value of different T lymphocyte markers

2016

[EN] The prognosis of non-small cell lung cancer (NSCLC) remains poor and heterogeneous and new biomarkers are needed. As the immune system plays a pivotal role in cancer, the study of immune-related markers may provide valuable prognostic information of NSCLC. In 122 formalin-fixed, paraffin-embedded tumor tissue samples from early-stage NSCLC, tumor and tumor-near stromal areas were microdissected and gene expression levels of conventional and regulatory T cell markers were assessed by quantitative polymerase chain reaction. Also, the presence of infiltrating CD4+, CD8+, and FOXP3+ cells in tumor samples was assessed by immunohistochemistry. The relative proportion of conventional and reg…

Sequential cleavage of the proteins encoded by HNOT/ALG3, the human counterpart of the Drosophila NOT and yeast ALG3 gene, results in products acting…

2017

This study provides first insights into the biosynthesis, structure, biochemistry and complex processing of the proteins encoded by hNOT/ALG3, the human counterpart of the Drosophila Neighbour of TID (NOT) and the yeast asparagine linked glycosylation 3 gene (ALG3), which encodes a mannosyltransferase. Unambiguous evidence that both the fly and human proteins act as mannosyltransferases has not been provided yet. Previously, we showed that hNOT/ALG3 encodes two alternatively spliced main transcripts, hNOT-1/ALG3-1 and hNOT-4/ALG3-4, and their 15 truncated derivatives that lack diverse sets of exons and/or carry point mutations that result in premature termination codons. Here we show that t…

A deterministic model for highly contagious diseases: The case of varicella

2016

[EN] The classic nonlinear Kermack-McKendrick model based upon a system of differential equations has been widely applied to model the rise and fall of global pandemic and also seasonal epidemic by introducing a forced harmonic infectivity which would change throughout the year. These methods work well in their respective domains of applicability, and for certain diseases, but they fail when both seasonality and high infectivity are combined. In this paper we consider a Susceptible-Infected-Recovered, or SIR, model with two latent states to model the propagation and evolutionary history of varicella in humans. We show that infectivity can be calculated from real data and we find a nonstanda…

Monitoring few molecular binding events in scalable confined aqueous compartments by raster image correlation spectroscopy (CADRICS)

2016

The assembly of scalable liquid compartments for binding assays in array formats constitutes a topic of fundamental importance in life sciences. This challenge can be addressed by mimicking the structure of cellular compartments with biological native conditions. Here, inkjet printing is employed to develop up to hundreds of picoliter aqueous droplet arrays stabilized by oil-confinement with mild surfactants (Tween-20). The aqueous environments constitute specialized compartments in which biomolecules may exploit their function and a wide range of molecular interactions can be quantitatively investigated. Raster Image Correlation Spectroscopy (RICS) is employed to monitor in each compartmen…

Identification of the Tetraspanin CD9 as an Interaction Partner of Organic Cation Transporters 1 and 2

2019

Organic cation transporters (OCTs) are membrane proteins with relevant physiological (because they accept neurotransmitters as substrate) and pharmacological (because of their interaction with drugs) roles. The human OCTs hOCT1 (SLC22A1/hOCT1) and hOCT2 (SLC22A2/hOCT2) are highly expressed in hepatic (hOCT1) and in renal and neuronal tissue (hOCT2), suggesting a possible role in modulating neurotransmitter activity in the liver, kidney, and brain, and their clearance from the blood. Even though there are several data demonstrating that OCTs are regulated under various patho-physiological conditions, it remains largely unknown which proteins directly interact with OCTs and thereby influence …