scholarly journals Techniques to Study Specific Cell-Surface Receptor-Mediated Cellular Vitamin A Uptake

2010 ◽  
pp. 341-361 ◽  
Author(s):  
Riki Kawaguchi ◽  
Hui Sun
Keyword(s):  
Vitamin A ◽  
Cell Surface ◽  
Cell Surface Receptor ◽  
Specific Cell ◽  
Surface Receptor ◽  
Specific Cell Surface

scholarly journals Determination of the molecular mass of apolipoprotein B-100 A chemical approach

1986 ◽  
Vol 239 (3) ◽  
pp. 777-780 ◽  
Author(s):  
C Y Yang ◽  
F S Lee ◽  
L Chan ◽  
D A Sparrow ◽  
J T Sparrow ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Apolipoprotein B ◽  
Cell Surface Receptor ◽  
Specific Cell ◽  
Apo B ◽  
Chemical Approach ◽  
Surface Receptor ◽  
Cnbr Cleavage ◽  
Specific Cell Surface

Apolipoprotein B-100 (apo B-100) is the protein ligand in low-density lipoproteins that binds to a specific cell-surface receptor. Its molecular mass has been a subject of controversy. We have determined the molecular mass of the protein by a chemical approach. After complete CNBr cleavage, the C-terminal fragment of apo B-100 was purified by reverse-phase h.p.l.c. Amino acid N- and C-terminal analyses confirm that this peptide represents the C-terminal peptide as deduced from the DNA sequence of a human apo B-100 cDNA clone. A chemically synthesized peptide was used to determine the recovery of the peptide (74.72%). On the basis of these data, the molecular mass of apo B-100 was determined to be 496.82 +/- 24.84 kDa.

Neurotransmitter Control of Secretion

1987 ◽  
Vol 66 (1_suppl) ◽  
pp. 628-632 ◽  
Author(s):  
B. J. Baum
Keyword(s):  
Plasma Membrane ◽  
Salivary Gland ◽  
Salivary Secretion ◽  
Cell Surface Receptor ◽  
Specific Cell ◽  
Neural Signal ◽  
N Protein ◽  
Transduction Mechanisms ◽  
Surface Receptor ◽  
Specific Cell Surface

It is very well established that the principal control of salivary secretion is derived from autonomic innervation. Transmission of a neural signal to a salivary gland acinar cell occurs chemically via neurotransmitters, the first messengers of a secretory response. Neurotransmitters bind to specific cell surface receptor proteins, an event which activates precise transduction mechanisms which then transfer the neural signal to the inside of the cell. There are two major transduction mechanisms operative in salivary gland acinar cells. One involves the generation of cAMP, the other involves the breakdown of plasma membrane polyphosphoinositides. For both mechanisms, the appropriate stimulated receptor activates a second plasma membrane protein, termed an N (or G) protein. The N protein requires GTP to activate an enzyme (adenylate cyclase or phospholipase C), which then catalyzes the formation of a second messenger (cAMP and inositol trisphosphatel diacylglyeerol, respectively). This action provides the intracellular signal for secretory events (protein, fluid, electrolyte secretion) to begin.

scholarly journals Decreased urokinase receptor expression by overexpression of the plasminogen activator in a colon cancer cell line

1992 ◽  
Vol 285 (2) ◽  
pp. 629-634 ◽  
Author(s):  
W Hollas ◽  
E Soravia ◽  
A Mazar ◽  
J Henkin ◽  
F Blasi ◽  
...  
Keyword(s):  
Cell Surface ◽  
Binding Site ◽  
Cell Line ◽  
Marker Gene ◽  
Receptor Expression ◽  
Cell Surface Receptor ◽  
Scatchard Analysis ◽  
Specific Cell ◽  
Ample Evidence ◽  
Surface Receptor

There is now ample evidence that the proteolytic action of urokinase (UK) is potentiated by a specific cell surface receptor. The present study was undertaken to determine the role of UK as a modulator of its binding site. GEO colonic cells, which secrete low levels of UK (approximately 2.5 ng/ml per 72 h per 10(6) cells) and display approx. 10(4) receptors per cell, the majority of which are vacant, were transfected with an exogenous UK gene driven by the RSV long terminal repeat (LTR) promoter (pRSVUK). Several UK-overexpressing pRSVUK clones were identified by an e.l.i.s.a., Northern blotting and Southern blotting, and analysed for receptor numbers after an acid pretreatment which dissociates receptor-bound UK. pRSVUK GEO clones, expressing high levels of UK, consistently bound 50-75% less radioactive di-isopropylfluorophosphate (DFP)-UK than clones harbouring the selectable marker gene neo only or control GEO cells. Cross-linking experiments with a radioactive N-terminal fragment of UK which binds to the receptor showed a decreased amount of a binding protein of approx. 51 kDa in representative pRSVUK-transfected cells. Saturation and Scatchard analysis indicated that this reduction in radioligand binding reflected a 40-70% decrease in the number of UK receptors, rather than a change in the dissociation constant. The reduction in receptor display could be accounted for by a decrease in the amount of steady-state mRNA encoding the receptor. Radioactive DFP-UK binding to pRSVUK GEO clones, which display two-thirds less receptors than their neo counterparts, could be restored to control levels (untreated cells harbouring neo) by cultivating them in the presence of an antibody which inhibits the interaction of UK with its receptor. These data suggest that for one colonic cell line at least, UK reduces the expression of its own binding site via an autocrine stimulation of its cell surface receptor.

scholarly journals Vitamin A Transport and the Transmembrane Pore in the Cell-Surface Receptor for Plasma Retinol Binding Protein

PLoS ONE ◽  
2013 ◽  
Vol 8 (11) ◽  
pp. e73838 ◽  
Author(s):  
Ming Zhong ◽  
Riki Kawaguchi ◽  
Mariam Ter-Stepanian ◽  
Miki Kassai ◽  
Hui Sun
Keyword(s):  
Vitamin A ◽  
Cell Surface ◽  
Binding Protein ◽  
Retinol Binding Protein ◽  
Cell Surface Receptor ◽  
Surface Receptor ◽  
Plasma Retinol ◽  
Vitamin A Transport

scholarly journals Disulfide-Linked Peptides for Blocking BTLA/HVEM Binding

2020 ◽  
Vol 21 (2) ◽  
pp. 636 ◽  
Author(s):  
Marta Spodzieja ◽  
Katarzyna Kuncewicz ◽  
Adam Sieradzan ◽  
Agnieszka Karczyńska ◽  
Justyna Iwaszkiewicz ◽  
...  
Keyword(s):  
Immune Responses ◽  
Potent Inhibitor ◽  
Cell Surface Receptor ◽  
Immune Checkpoints ◽  
T Cell Proliferation ◽  
Specific Cell ◽  
Rich Domain ◽  
Surface Receptor ◽  
Specific Cell Surface ◽  
Cysteine Rich Domain

Immune checkpoints are crucial in the maintenance of antitumor immune responses. The activation or blockade of immune checkpoints is dependent on the interactions between receptors and ligands; such interactions can provide inhibitory or stimulatory signals, including the enhancement or suppression of T-cell proliferation, differentiation, and/or cytokine secretion. B-and T-lymphocyte attenuator (BTLA) is a lymphoid-specific cell surface receptor which is present on T-cells and interacts with herpes virus entry mediator (HVEM), which is present on tumor cells. The binding of HVEM to BTLA triggers an inhibitory signal which attenuates the immune response. This feature is interesting for studying the molecular interactions between HVEM and BTLA, as they may be targeted for novel immunotherapies. This work was based on the crystal structure of the BTLA/HVEM complex showing that BTLA binds the N-terminal cysteine-rich domain of HVEM. We investigated the amino acid sequence of HVEM and used molecular modeling methods to develop inhibitors of the BTLA/HVEM interaction. We synthesized novel compounds and determined their ability to interact with the BTLA protein and inhibit the formation of the BTLA/HVEM complex. Our results suggest that the HVEM (14–39) peptide is a potent inhibitor of the formation of the BTLA/HVEM protein complex.

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