scholarly journals Membrane retrieval in the guinea-pig neurohypophysis. Isolation and characterization of secretory vesicles and coated microvesicles after radiolabel incorporation in vivo

1984 ◽  
Vol 218 (2) ◽  
pp. 591-599 ◽  
Author(s):  
T Saermark ◽  
P M Jones ◽  
I C A F Robinson
Keyword(s):  
Guinea Pig ◽  
Biochemical Characterization ◽  
Hormone Secretion ◽  
Secretory Vesicle ◽  
Small Scale ◽  
Secretory Vesicles ◽  
Isolation And Characterization ◽  
Pituitary Glands

We have developed small-scale methods for the isolation and biochemical characterization of subcellular fractions from single guinea-pig posterior-pituitary glands. Secretory vesicles and coated microvesicles produced in this way were of similar purity to those isolated from large amounts of tissue by conventional ultracentrifugation. [35S]Cysteine injected into the hypothalamus was found in the soluble contents of secretory vesicles isolated from the neural lobes 24 h later. High-pressure liquid-chromatographic analysis revealed that the radiolabel was incorporated into the expected neurosecretory products (oxytocin, vasopressin and neurophysin) and also into a biosynthetic intermediate in the vasopressin system. The membranes of secretory vesicles were labelled with [3H]choline 24 h after its hypothalamic injection. Little or no [3H]choline could be demonstrated in coated microvesicles at this time, although these structures were labelled 5 days after injection. Stimulating hormone secretion by chronic dehydration produced a significant fall in [3H]choline content of the secretory-vesicle membranes without any transfer of label into coated microvesicles, suggesting that coated microvesicles are not involved in membrane retrieval in the neurohypophysis.

Biochemical characterization of Yin Yang 1 – RNA complexes

2008 ◽  
Vol 86 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Zachery R. Belak ◽  
Andrew Ficzycz ◽  
Nick Ovsenek
Keyword(s):  
Rna Binding ◽  
Biochemical Characterization ◽  
Ribonucleoprotein Complexes ◽  
Yin Yang 1 ◽  
Significant Difference ◽  
Yin Yang ◽  
Rna Interaction ◽  
Rna Complexes

YY1 (Yin Yang 1) is present in the Xenopus oocyte cytoplasm as a constituent of messenger ribonucleoprotein complexes (mRNPs). Association of YY1 with mRNPs requires direct RNA-binding activity. Previously, we have shown YY1 has a high affinity for U-rich RNA; however, potential interactions with plausible in vivo targets have not been investigated. Here we report a biochemical characterization of the YY1–RNA interaction including an investigation of the stability, potential 5′-methylguanosine affinity, and specificity for target RNAs. The formation of YY1–RNA complexes in vitro was highly resistant to thermal, ionic, and detergent disruption. The endogenous oocyte YY1–mRNA interactions were also found to be highly stable. Specific YY1–RNA interactions were observed with selected mRNA and 5S RNA probes. The affinity of YY1 for these substrates was within an order of magnitude of that for its cognate DNA element. Experiments aimed at determining the potential role of the 7-methylguanosine cap on RNA-binding reveal no significant difference in the affinity of YY1 for capped or uncapped mRNA. Taken together, the results show that the YY1–RNA interaction is highly stable, and that YY1 possesses the ability to interact with structurally divergent RNA substrates. These data are the first to specifically document the interaction between YY1 and potential in vivo targets.

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
Keyword(s):  
Molecular Motors ◽  
Cell Biology ◽  
Budding Yeast ◽  
Isolation And Characterization ◽  
Sequence Homologies ◽  
Binding Factor ◽  
Microtubule Motor

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.

scholarly journals Isolation and characterization of adrenocortical progenitors involved in the adaptation to stress

2018 ◽  
Vol 115 (51) ◽  
pp. 12997-13002 ◽  
Author(s):  
Charlotte Steenblock ◽  
Maria F. Rubin de Celis ◽  
Luis F. Delgadillo Silva ◽  
Verena Pawolski ◽  
Ana Brennand ◽  
...  
Keyword(s):  
Lineage Tracing ◽  
Differentiated Cells ◽  
Isolation And Characterization ◽  
Proliferation And Differentiation ◽  
Response To Stress ◽  
Steroidogenic Cells ◽  
High Degree

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.

scholarly journals Pharmaceutical properties of 'sucupira' (Pterodon spp.)

2010 ◽  
Vol 46 (4) ◽  
pp. 607-616 ◽  
Author(s):  
Daiane Hansen ◽  
Mitsue Haraguchi ◽  
Antonio Alonso
Keyword(s):  
Biological Effects ◽  
Chemical Compounds ◽  
Experimental Models ◽  
Popular Medicine ◽  
Isolation And Characterization ◽  
Pharmaceutical Properties ◽  
The Relationship

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.

scholarly journals Isolation and characterization of the dopa decarboxylase gene of Drosophila melanogaster

1981 ◽  
Vol 1 (6) ◽  
pp. 475-485
Author(s):  
J Hirsh ◽  
N Davidson
Keyword(s):  
Drosophila Melanogaster ◽  
Ribonucleic Acid ◽  
Deoxyribonucleic Acid ◽  
Isolation Procedure ◽  
Chromosome Band ◽  
Dopa Decarboxylase ◽  
Developmental Profile ◽  
Isolation And Characterization

We have isolated chromosomal deoxyribonucleic acid clones containing the Drosophila dopa decarboxylase gene. We describe an isolation procedure which can be applied to other nonabundantly expressed Drosophila genes. The dopa decarboxylase gene lies within or very near polytene chromosome band 37C1-2. The gene is interrupted by at least one intron, and the primary mode of regulation is pretranslational. At least two additional sequences hybridized by in vivo ribonucleic acid-derived probes are found within a 35-kilobase region surrounding the gene. The developmental profile of ribonucleic acid transcribed from one of these regions differs from that of the dopa decarboxylase transcript.

scholarly journals Ex Vivo Isolation and Characterization of Cd4+Cd25+ T Cells with Regulatory Properties from Human Blood

2001 ◽  
Vol 193 (11) ◽  
pp. 1303-1310 ◽  
Author(s):  
Detlef Dieckmann ◽  
Heidi Plottner ◽  
Susanne Berchtold ◽  
Thomas Berger ◽  
Gerold Schuler
Keyword(s):  
T Cells ◽  
Cytotoxic T Lymphocyte ◽  
Ex Vivo ◽  
Cell Receptor ◽  
Regulatory Cells ◽  
Suppressor T Cells ◽  
Isolation And Characterization ◽  
Regulatory Properties

It has been known for years that rodents harbor a unique population of CD4+CD25+ “professional” regulatory/suppressor T cells that is crucial for the prevention of spontaneous autoimmune diseases. Here we demonstrate that CD4+CD25+CD45RO+ T cells (mean 6% of CD4+ T cells) are present in the blood of adult healthy volunteers. In contrast to previous reports, these CD4+CD25+ T cells do not constitute conventional memory cells but rather regulatory cells exhibiting properties identical to their rodent counterparts. Cytotoxic T lymphocyte–associated antigen (CTLA)-4 (CD152), for example, which is essential for the in vivo suppressive activity of CD4+CD25+ T cells, was constitutively expressed, and remained strongly upregulated after stimulation. The cells were nonproliferative to stimulation via their T cell receptor for antigen, but the anergic state was partially reversed by interleukin (IL)-2 and IL-15. Upon stimulation with allogeneic (but not syngeneic) mature dendritic cells or platebound anti-CD3 plus anti-CD28 the CD4+CD25+ T cells released IL-10, and in coculture experiments suppressed the activation and proliferation of CD4+ and CD8+ T cells. Suppression proved IL-10 independent, yet contact dependent as in the mouse. The identification of regulatory CD4+CD25+ T cells has important implications for the study of tolerance in man, notably in the context of autoimmunity, transplantation, and cancer.

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