scholarly journals Isolation and characterization of a gene (CBF2) specifying a protein component of the budding yeast kinetochore.

1993 ◽  
Vol 121 (3) ◽  
pp. 513-519 ◽  
Author(s):  
W Jiang ◽  
J Lechner ◽  
J Carbon

We have cloned and determined the nucleotide sequence of the gene (CBF2) specifying the large (110 kD) subunit of the 240-kD multisubunit yeast centromere binding factor CBF3, which binds selectively in vitro to yeast centromere DNA and contains a minus end-directed microtubule motor activity. The deduced amino acid sequence of CBF2p shows no sequence homologies with known molecular motors, although a consensus nucleotide binding site is present. The CBF2 gene is essential for viability of yeast and is identical to NDC10, in which a conditional mutation leads to a defect in chromosome segregation (Goh, P.-Y., and J. V. Kilmartin, in this issue of The Journal of Cell Biology). The combined in vitro and in vivo evidence indicate that CBF2p is a key component of the budding yeast kinetochore.

2018 ◽  
Vol 115 (51) ◽  
pp. 12997-13002 ◽  
Author(s):  
Charlotte Steenblock ◽  
Maria F. Rubin de Celis ◽  
Luis F. Delgadillo Silva ◽  
Verena Pawolski ◽  
Ana Brennand ◽  
...  

The adrenal gland is a master regulator of the human body during response to stress. This organ shows constant replacement of senescent cells by newly differentiated cells. A high degree of plasticity is critical to sustain homeostasis under different physiological demands. This is achieved in part through proliferation and differentiation of adult adrenal progenitors. Here, we report the isolation and characterization of a Nestin+ population of adrenocortical progenitors located under the adrenal capsule and scattered throughout the cortex. These cells are interconnected with progenitors in the medulla. In vivo lineage tracing revealed that, under basal conditions, this population is noncommitted and slowly migrates centripetally. Under stress, this migration is greatly enhanced, and the cells differentiate into steroidogenic cells. Nestin+ cells cultured in vitro also show multipotency, as they differentiate into mineralocorticoid and glucocorticoid-producing cells, which can be further influenced by the exposure to Angiotensin II, adrenocorticotropic hormone, and the agonist of luteinizing hormone-releasing hormone, triptorelin. Taken together, Nestin+ cells in the adult adrenal cortex exhibit the features of adrenocortical progenitor cells. Our study provides evidence for a role of Nestin+ cells in organ homeostasis and emphasizes their role under stress. This cell population might be a potential source of cell replacement for the treatment of adrenal insufficiency.


2010 ◽  
Vol 46 (4) ◽  
pp. 607-616 ◽  
Author(s):  
Daiane Hansen ◽  
Mitsue Haraguchi ◽  
Antonio Alonso

The plant of the genus Pterodon (Fabaceae, Leguminosae), commonly known as 'sucupira' or 'faveira', are disseminated throughout the central region of Brazil and has frequently been used in popular medicine for its anti-rheumatic, analgesic, and anti-inflammatory properties. In recent years, interest in these plants has increased considerably. The biological effects of different phytoextracts and pure metabolites have been investigated in several experimental models in vivo and in vitro. The literature describes flavonoids, triterpene and steroids, while one paper presented studies with proteins isolated from the genus. This review provides an overview of phytochemical and pharmacological research in Pterodon, showing the main chemical compounds studied to date, and focusing on the relationship between these molecules and their biological activity. Furthermore, this study paves the way for more in-depth investigation, isolation and characterization of the molecules of this plant genus.


2020 ◽  
Vol 11 ◽  
Author(s):  
Sandra Quilodrán-Vega ◽  
Leonardo Albarracin ◽  
Flavia Mansilla ◽  
Lorena Arce ◽  
Binghui Zhou ◽  
...  

Potential probiotic or immunobiotic effects of lactic acid bacteria (LAB) isolated from the milk of the South American camelid llama (Lama glama) have not been reported in published studies. The aim of the present work was to isolate beneficial LAB from llama milk that can be used as potential probiotics active against bacterial pathogens. LAB strains were isolated from llama milk samples. In vitro functional characterization of the strains was performed by evaluating the resistance against gastrointestinal conditions and inhibition of the pathogen growth. Additionally, the adhesive and immunomodulatory properties of the strains were assessed. The functional studies were complemented with a comparative genomic evaluation and in vivo studies in mice. Ligilactobacillus salivarius TUCO-L2 showed enhanced probiotic/immunobiotic potential compared to that of other tested strains. The TUCO-L2 strain was resistant to pH and high bile salt concentrations and demonstrated antimicrobial activity against Gram-negative intestinal pathogens and adhesion to mucins and epithelial cells. L. salivarius TUCO-L2 modulated the innate immune response triggered by Toll-like receptor (TLR)-4 activation in intestinal epithelial cells. This effect involved differential regulation of the expression of inflammatory cytokines and chemokines mediated by the modulation of the negative regulators of the TLR signaling pathway. Moreover, the TUCO-L2 strain enhanced the resistance of mice to Salmonella infection. This is the first report on the isolation and characterization of a potential probiotic/immunobiotic strain from llama milk. The in vitro, in vivo, and in silico investigation performed in this study reveals several research directions that are needed to characterize the TUCO-L2 strain in detail to position this strain as a probiotic or immunobiotic that can be used against infections in humans or animals, including llama.


1993 ◽  
Vol 122 (3) ◽  
pp. 623-633 ◽  
Author(s):  
TE Morgan ◽  
RO Lockerbie ◽  
LS Minamide ◽  
MD Browning ◽  
JR Bamburg

Actin depolymerizing factor (ADF) is an 18.5-kD protein with pH-dependent reciprocal F-actin binding and severing/depolymerizing activities. We previously showed developing muscle down-regulates ADF (J. R. Bamburg and D. Bray. 1987. J. Cell Biol. 105: 2817-2825). To further study this process, we examined ADF expression in chick myocytes cultured in vitro. Surprisingly, ADF immunoreactivity increases during the first 7-10 d in culture. This increase is due to the presence of a new ADF species with higher relative molecular weight which reacts identically to brain ADF with antisera raised against either brain ADF or recombinant ADF. We have purified both ADF isoforms from myocytes and have shown by peptide mapping and partial sequence analysis that the new isoform is structurally related to ADF. Immunoprecipitation of both isoforms from extracts of cells prelabeled with [32P]orthophosphate showed that the new isoform is radiolabeled, predominantly on a serine residue, and hence is called pADF. pADF can be converted into a form which comigrates with ADF on 1-D and 2-D gels by treatment with alkaline phosphatase. pADF has been quantified in a number of cells and tissues where it is present from approximately 18% to 150% of the amount of unphosphorylated ADF. pADF, unlike ADF, does not bind to G-actin, or affect the rate or extent of actin assembly. Four ubiquitous protein kinases failed to phosphorylate ADF in vitro suggesting that ADF phosphorylation in vivo is catalyzed by a more specific kinase. We conclude that the ability to regulate ADF activity is important to muscle development since myocytes have both pre- and posttranslational mechanisms for regulating ADF activity. The latter mechanism is apparently a general one for cell regulation of ADF activity.


Blood ◽  
2017 ◽  
Vol 129 (10) ◽  
pp. 1284-1295 ◽  
Author(s):  
Lorenz Jahn ◽  
Pleun Hombrink ◽  
Renate S. Hagedoorn ◽  
Michel G. D. Kester ◽  
Dirk M. van der Steen ◽  
...  

Key Points Isolation and characterization of a high-affinity TCR targeting the intracellular B cell–specific transcription factor BOB1. T cells expressing a BOB1-specific TCR lysed and eradicated primary multiple myeloma and other B-cell malignancies in vitro and in vivo.


1997 ◽  
Vol 17 (5) ◽  
pp. 2679-2687 ◽  
Author(s):  
S Minoguchi ◽  
Y Taniguchi ◽  
H Kato ◽  
T Okazaki ◽  
L J Strobl ◽  
...  

RBP-Jkappa is a sequence-specific DNA binding protein which plays a central role in signalling downstream of the Notch receptor by physically interacting with its intracellular region. Although at least four Notch genes exist in mammals, it is unknown whether each Notch requires a specific downstream signalling molecule. Here we report isolation and characterization of a mouse RBP-Jkappa-related gene named RBP-L that is expressed almost exclusively in lung, in contrast to the ubiquitous expression of RBP-Jkappa. For simplicity, we propose to call RBP-Jkappa RBP-J. The RBP-L protein bound to a DNA sequence almost identical to that of RBP-J. Surprisingly, RBP-L did not interact with any of the known four mouse Notch proteins. Although we found that RBP-L and EBNA-2 cooperated in transcriptional activation, they did not show significantly strong protein-protein interaction that can be detected by several in vivo and in vitro assays. This is again in contrast to physical association of RBP-J with EBNA-2. Several models to explain functional interaction between RBP-L and EBNA-2 are discussed.


2021 ◽  
Author(s):  
Kat Pick ◽  
Tingting Ju ◽  
Benjamin P. Willing ◽  
Tracy Lyn Raivio

In this study, we describe the isolation and characterization of novel bacteriophage vB_EcoP_Kapi1 (Kapi1) isolated from a strain of commensal Escherichia coli inhabiting the gastrointestinal tract of healthy mice. We show that Kapi1 is a temperate phage integrated into tRNA argW of strain MP1 and describe its genome annotation and structure. Kapi1 shows limited homology to other characterized prophages but is most similar to the seroconverting phages of Shigella flexneri, and clusters taxonomically with P22-like phages. The receptor for Kapi1 is the lipopolysaccharide O-antigen, and we further show that Kapi1 alters the structure of its hosts O-antigen in multiple ways.  Kapi1 displays unstable lysogeny, and we find that lysogeny is favored during growth in simulated intestinal fluid. Furthermore, Kapi1 lysogens have a competitive advantage over their non-lysogenic counterparts both in vitro and in vivo, suggesting a role for Kapi1 during colonization. We thus report the use of MP1 and Kapi1 as a model system to explore the molecular mechanisms of mammalian colonization by E. coli to ask what the role(s) of prophages in this context might be.


2021 ◽  
Author(s):  
Tal Noy-Porat ◽  
Adva Mechaly ◽  
Yinon Levy ◽  
Efi Makdasi ◽  
Ron Alcalay ◽  
...  

AbstractSince the onset of the current COVID-19 pandemic, high priority is given to the development of neutralizing antibodies, as a key approach for the design of therapeutic strategies to countermeasure and eradicate the disease. Previously, we reported the development of human therapeutic monoclonal antibodies (mAbs) exhibiting very high protective ability. These mAbs recognize epitopes on the spike receptor binding domain (RBD) of SARS-CoV-2 that is considered to represent the main rout of receptor engagement by the SARS-CoV-2 virus. The recent emergence of viral variants emphasizes the notion that efficient antibody treatments need to rely on mAbs against several distinct key epitopes in order to circumvent the occurrence of therapy escape-mutants. Here we report the isolation and characterization of 12 neutralizing mAbs, identified by screening a phage-display library constructed from lymphatic cells collected from severe COVID-19 patients. The antibodies target three distinct epitopes on the spike N-terminal domain (NTD) of SARS-CoV-2, one of them defining a major site of vulnerability of the virus. Extensive characterization of these mAbs suggests a neutralization mechanism which relies both on amino-acid and N-glycan recognition on the virus, and involvement of receptors other than the hACE2 on the target cell. Two of the selected mAbs, which demonstrated superior neutralization potency in vitro, were further evaluated in vivo, demonstrating their ability to fully protect K18-hACE2 transgenic mice even when administered at low doses and late after infection. The study demonstrates the high potential of the mAbs for therapy of SARS-CoV-2 infection and underlines the possible role of the NTD in mediating infection of host cells via alternative cellular portals other than the canonical ACE2 receptor.


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