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581.
Ayelet R. Amsalem Barak Marom Keren E. Shapira Tal Hirschhorn Livia Preisler Pia Paarmann Petra Knaus Yoav I. Henis Marcelo Ehrlich 《Molecular biology of the cell》2016,27(4):716-730
The expression and function of transforming growth factor-β superfamily receptors are regulated by multiple molecular mechanisms. The type II BMP receptor (BMPRII) is expressed as two alternatively spliced forms, a long and a short form (BMPRII-LF and –SF, respectively), which differ by an ∼500 amino acid C-terminal extension, unique among TGF-β superfamily receptors. Whereas this extension was proposed to modulate BMPRII signaling output, its contribution to the regulation of receptor expression was not addressed. To map regulatory determinants of BMPRII expression, we compared synthesis, degradation, distribution, and endocytic trafficking of BMPRII isoforms and mutants. We identified translational regulation of BMPRII expression and the contribution of a 3’ terminal coding sequence to this process. BMPRII-LF and -SF differed also in their steady-state levels, kinetics of degradation, intracellular distribution, and internalization rates. A single dileucine signal in the C-terminal extension of BMPRII-LF accounted for its faster clathrin-mediated endocytosis relative to BMPRII-SF, accompanied by mildly faster degradation. Higher expression of BMPRII-SF at the plasma membrane resulted in enhanced activation of Smad signaling, stressing the potential importance of the multilayered regulation of BMPRII expression at the plasma membrane. 相似文献
582.
Pamela Alegranci Livia Carolina de Abreu Ribeiro Lucas Souza Ferreira Thais de Cássia Negrini Danielle Cardoso Geraldo Maia Aline Tansini Amanda Costa Gonçalves Marisa Campos Polesi Placeres Iracilda Zeppone Carlos 《Mycopathologia》2013,176(1-2):57-65
Sporotrichosis is a subcutaneous mycosis that is caused by the dimorphic fungus Sporothrix schenckii. This disease generally occurs within the skin and subcutaneous tissues, causing lesions that can spread through adjacent lymphatic vessels and sometimes leading to systemic diseases in immunocompromised patients. Macrophages are crucial for proper immune responses against a variety of pathogens. Furthermore, macrophages can play different roles in response to different microorganisms and forms of activation, and they can be divided into “classic” or “alternatively” activated populations, as also known as M1 and M2 macrophages. M1 cells can lead to tissue injury and contribute to pathogenesis, whereas M2 cells promote angiogenesis, tissue remodeling, and repair. The aim of this study was to investigate the roles of M1 and M2 macrophages in a sporotrichosis model. Toward this end, we performed phenotyping of peritoneal exudate cells and evaluated the concomitant production of several immunomediators, including IL-12, IL-10, TGF-β, nitric oxide, and arginase-I activity, which were stimulated ex vivo with cell wall peptide-polysaccharide. Our results showed the predominance of the M2 macrophage population, indicated by peaks of arginase-I activity as well as IL-10 and TGF-β production during the 6th and 8th weeks after infection. These results were consistent with cellular phenotyping that revealed increases in CD206-positive cells over this period. This is the first report of the participation of M2 macrophages in sporotrichosis infections. 相似文献
583.
John Salogiannis Jenna R. Christensen Livia D. Songster Adriana Aguilar-Maldonado Nandini Shukla Samara L. Reck-Peterson 《Molecular biology of the cell》2021,32(6):492
In canonical microtubule-based transport, adaptor proteins link cargoes to dynein and kinesin motors. Recently, an alternative mode of transport known as “hitchhiking” was discovered, where cargoes achieve motility by hitching a ride on already-motile cargoes, rather than attaching to a motor protein. Hitchhiking has been best studied in two filamentous fungi, Aspergillus nidulans and Ustilago maydis. In U. maydis, ribonucleoprotein complexes, peroxisomes, lipid droplets (LDs), and endoplasmic reticulum hitchhike on early endosomes (EEs). In A. nidulans, peroxisomes hitchhike using a putative molecular linker, peroxisome distribution mutant A (PxdA), which associates with EEs. However, whether other organelles use PxdA to hitchhike on EEs is unclear, as are the molecular mechanisms that regulate hitchhiking. Here we find that the proper distribution of LDs, mitochondria, and preautophagosomes do not require PxdA, suggesting that PxdA is a peroxisome-specific molecular linker. We identify two new pxdA alleles, including a point mutation (R2044P) that disrupts PxdA’s ability to associate with EEs and reduces peroxisome movement. We also identify a novel regulator of peroxisome hitchhiking, the phosphatase DipA. DipA colocalizes with EEs and its association with EEs relies on PxdA. Together, our data suggest that PxdA and the DipA phosphatase are specific regulators of peroxisome hitchhiking on EEs. 相似文献
584.
Evidence for the presence of β-subunit of hexosaminidase in a case of Sandhoff disease using a blotting technique 总被引:1,自引:0,他引:1
Sophie Gautron Livia Poenaru Joëlle Boue Hugues Puissant Jan J. W. Lisman Jean-Claude Dreyfus 《Human genetics》1983,63(3):258-261
Hexosaminidases, lysosomal enzymes whose deficiency is responsible for several genetic disorders, exist as two major forms: form A, containing two types of subunits alpha and beta; and form B, containing only beta subunits. We have used a technique involving successively electrophoresis of denatured proteins, transfer (blotting) onto nitrocellulose, and labelling by appropriate antibodies raised against the dissociated forms of hexosaminidases A and B. This technique allows the detection of alpha and beta subunits in crude extracts of normal tissues. The presence of beta chains was demonstrated in the liver of a fetus affected with Sandhoff's disease, deficient in functional hexosaminidases A and B. 相似文献
585.
Summary Phospholamban (PLB), a 52-residue integral membrane protein of the cardiac sarcoplasmic reticulum, is known as the regulator of the Ca2+-ATPase pump via its phosphorylation-dephosphorylation at Ser16. In order to investigate the structural effects of the phosphorylation on the cytoplasmic domain of PLB, we synthesized PLB 2–33 in its nonphosphorylated and phosphorylated forms using Fmoc chemistry. PLB 2–33 was phosphorylated using the global phosphorylation method. Phosphorylation with di-t-butyl-N,N-diisopropylphosphoramidite led to an incomplete reaction (nonphosphorylated peptide was recovered) and to the formation of an H-phosphonate. In contrast, the use of dibenzyl-N,N-diisopropylphosphoramidite yielded the desired phosphorylated peptide quantitatively and did not give rise to the H-phosphonate. Our results show the effectiveness of the dibenzyl-protected phosphoramidite when the site to be phosphorylated is particularly hindered. 相似文献
586.
The possibili that urinary glutamine transaminase K activity might be a marker of a proximal tubule segment-specific response to mercuric chloride was investigated in male rats after a single i.p. injection in time-course and dose-response experiments. Urinary total proteins and angiotensin converting enzyme activity were determined simultaneously. Urinary indices showed an early increase (within 5 h of treatment) of total proteins and angiotensin converting enzyme, whereas glubmine transaminase K increased 10 h after treatment. The peak of all these indices was observed 24 h after mercuric chloride injection. The lowest dose that induced a significant increase in proteins and enzymes was 0.25 mg kg-1; in addition, a dose-response effect was observed. Glutamine transaminase K appeared to be an early and sensitive index of response of mercuric chloride effects, similar to total proteins and angiotensin converting enzyme. It is suggested that this enzyme is mainly localized in the 'pars recta' of the proximal tubule. Therefore glutamine transaminase K might be a segment-specific marker for the detection of damage localized in this portion of the proximal tubule. 相似文献
587.
588.
Semicontinuous system for the production of recombinant mCherry protein in Chlamydomonas reinhardtii
Cesar Andres Diaz Arias Marcelo Chuei Matsudo Livia Seno Ferreira-Camargo João Vitor Dutra Molino Stephen Patrick Mayfield João Carlos Monteiro de Carvalho 《Biotechnology progress》2021,37(2):e3101
Biotechnology advances have allowed bacteria, yeasts, plants, mammalian and insect cells to function as heterologous protein expression systems. Recently, microalgae have gained attention as an innovative platform for recombinant protein production, due to low culture media cost, compared to traditional systems, as well as the fact that microalgae such as Chlamydomonas reinhardtii are considered safe (GRAS) by the Food and Drug Administration (FDA). Previous studies showed that recombinant protein production in traditional platforms by semicontinuous process increased biomass and bio product productivity, when compared to batch process. As there is a lack of studies on semicontinuous process for recombinant protein production in microalgae, the production of recombinant mCherry fluorescent protein was evaluated by semicontinuous cultivation of Chlamydomonas reinhardtii in bubble column photobioreactor. This semicontinuous cultivation process was evaluated in the following conditions: 20%, 40%, and 60% culture portion withdrawal. The highest culture withdrawal percentage (60%) provided the best results, as an up to 161% increase in mCherry productivity (454.5 RFU h−1 – Relative Fluorescence Unit h−1), in comparison to batch cultivation (174.0 RFU h−1) of the same strain. All cultivations were carried out for 13 days, at pH 7, temperature 25°C and, by semicontinuous process, two culture withdrawals were taken during the cultivations. Throughout the production cycles, it was possible to obtain biomass concentration up to 1.36 g L−1. 相似文献
589.
Becoming a psychiatrist in Europe: the title is recognized across the European Union,but what are the differences in training,salary and working hours?
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590.
Livia Zapponi Marta Del Bianco Luca Luiselli Andrea Catorci Marco A. Bologna 《Mammalian Biology》2013,78(3):157-163
The study of the effect of habitat fragmentation on species that inhabit residual patches requires the investigation of the relationship existing between species distribution and landscape components. To understand which components of landscape mosaics are more influential for species’ persistence, we compared the distribution of two arboreal rodents proved to be sensitive to habitat fragmentation, the hazel dormouse Muscardinus avellanarius and the red squirrel Sciurus vulgaris. Their occurrence in residual oak woods in central Italy was studied with nest-boxes and hair-tubes, developing a new method for hair analysis. Their distributions were analysed considering patch, matrix composition and configuration, and landscape vegetation variables. The two species showed a different degree of plasticity, with the squirrel being significantly more specialised at the landscape scale. The comparison of the two distribution patterns highlighted the influence of different ecological constraints and the existence of different strategies to cope with fragmentation. Patch size and patch attributes were generally weaker determinants of occurrence, compared to landscape metrics. The squirrel presence was significantly influenced by the presence of shared perimeter between hedgerows and woods and by the lack of isolation of the residual patches, suggesting the use of several fragments to compensate the low habitat quality. Conversely the hazel dormouse seemed to be more affected by the internal management of the woods, and in particular by the mean DBH. Our results highlight how the recognition of the extrinsic constraints and the influence of multi-scale habitat selection may help guiding land use management, to ensure species conservation in profoundly exploited landscapes. 相似文献