scholarly journals Rat lung lectin synthesis, degradation and activation. Developmental regulation and modulation by dexamethasone

1987 ◽  
Vol 245 (3) ◽  
pp. 683-690 ◽  
Author(s):  
L B Clerch ◽  
P L Whitney ◽  
D Massaro
Keyword(s):  
Binding Protein ◽  
Developmental Regulation ◽  
Fold Increase ◽  
Rat Lung ◽  
Absolute Rate ◽  
Lectin Activity ◽  
Developmentally Regulated ◽  
Rat Pups ◽  
The Absolute

Soluble lectins are widely distributed cell-agglutinating proteins. Their activity is developmentally regulated in several tissues, including the lung, but virtually nothing is known about the mechanisms of the developmental regulation or the turnover of these proteins. We studied mechanisms that might be responsible for the developmentally regulated changes in the activity of a lectin (beta-galactoside-binding protein) found in the lung, and determined if its activity or turnover could be modulated by treatment of rat pups with a glucocorticosteroid hormone (dexamethasone). Our studies on the activity and turnover of the lectin indicated that the peak of lectin activity (units/mg of protein) that occurred at age 12 days appeared to be brought about by two means: an increase in the activity of the lectin molecule itself (units/micrograms of lectin) that occurred at age 8 days, and 1.5-fold increase in the absolute rate of lectin synthesis at age 11 days. The decline in lectin activity was associated with a decrease in its rate of synthesis, return to the baseline extent of activation, and an increased rate of degradation. Treatment of rat pups with dexamethasone diminished the peak of lectin activity (units/mg of protein) by about 25%. This effect of dexamethasone was due, at least in part, to the complete prevention of activation of the lectin molecule (units/micrograms of lectin) and a premature increase in the rate of lectin degradation. Perhaps the normal fall in lectin activity after age 11 days is caused by mechanisms induced by the increase in serum corticosteroid that occurs at that age.

scholarly journals The subcellular localization of the β-galactoside-binding protein of rat lung

1982 ◽  
Vol 204 (1) ◽  
pp. 97-102 ◽  
Author(s):  
G L Sanford ◽  
L D Davis ◽  
J T Powell
Keyword(s):  
Subcellular Localization ◽  
Immunoglobulin G ◽  
Specific Binding ◽  
Binding Protein ◽  
Rat Lung ◽  
Lectin Activity ◽  
Intracellular Location ◽  
Immature Rat ◽  
Adult Rat ◽  
Rat Lungs

The subcellular localization of the beta-galactoside-binding protein, or lectin, from rat lung was investigated by the specific binding of anti-lectin immunoglobulin G to subcellular fractions. We used both adult and immature (12-day-old) rats; the immature rat lungs have an 8-10-fold greater concentration than adult rat lungs [Powell & Whitney (1980) Biochem. J. 188, 1-8]. In both groups of animals we observed greater specific binding of anti-lectin immunoglobulin G to intracellular membrane (mitochondrial and microsomal fractions) than to plasma membranes. Pre-incubation of membrane fractions with lactose resulted in a marked diminution of anti-lectin immunoglobulin G binding. In the adult rat lung most (approx. 80%) of the lectin activity was membrane-associated. In the immature rat lung only approx. 30% of the lectin activity was membrane associated and most of the beta-galactoside-binding protein appeared to be a soluble cytoplasmic component. The rat lung beta-galactoside-binding protein appeared to have a broad but predominantly intracellular location, being associated with membranes through one of its galactoside-binding sites.

Developmental regulation of PV-1 in rat lung: association with the nuclear envelope and limited colocalization with Cav-1

2005 ◽  
Vol 288 (2) ◽  
pp. L275-L284 ◽  
Author(s):  
Robert Hnasko ◽  
Nira Ben-Jonathan
Keyword(s):  
Endothelial Cells ◽  
Nuclear Envelope ◽  
Developmental Regulation ◽  
Intracellular Localization ◽  
Mrna Levels ◽  
Rat Lung ◽  
Developmentally Regulated ◽  
Caveolin 1 ◽  
Adult Lung ◽  
Lung Endothelial Cells

Plasmalemma vesicle protein-1 (PV-1) is a caveolae-associated protein that is enriched in lung endothelial cells. The PV-1 protein is first detected in the lung at embryonic day 12, before that of caveolin-1 (Cav-1). There is a postnatal rise in PV-1 and Cav-1 mRNA levels, reaching a peak at the time of weaning and declining to their lowest levels in the adult lung. In contrast, the PV-1 protein progressively increases during postnatal development with its highest levels in the adult lung; the Cav-1 protein remains relatively constant throughout this period. Alveolar endothelial cells express both PV-1 and Cav-1 proteins, but PV-1, unlike Cav-1, is also detectable in some bronchial epithelial cells. Endothelial cells transfected with a rat PV-1 construct show a punctate membrane distribution of PV-1, perinuclear accumulation, and an association with the nuclear envelope. In these cells, PV-1 exhibits only partial perinuclear colocalization with Cav-1 and F-actin. In summary, PV-1 is developmentally regulated in the rat lung and shows a divergent intracellular localization, with a limited caveolae/Cav-1 colocalization in cultured endothelial cells.

scholarly journals Endogenous ligands of rat lung β-galactoside-binding protein (galaptin) isolated by affinity chromatography on carboxyamidomethylated-galaptin-Sepharose

1984 ◽  
Vol 223 (3) ◽  
pp. 769-774 ◽  
Author(s):  
J T Powell ◽  
P L Whitney
Keyword(s):  
Binding Protein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Affinity Matrix ◽  
Rat Lung ◽  
Developmentally Regulated ◽  
Endogenous Ligands ◽  
Matrix Bound ◽  
Postnatal Lung Development ◽  
Developing Rat

Rat lung beta-galactoside-binding protein (galaptin) is developmentally regulated during postnatal lung development. In common with other vertebrate galaptins, it is very labile when purified and dependent on the presence of exogenous thiol reagents. Reaction of rat lung galaptin with iodoacetamide resulted in a stable active carboxyamidomethylated galaptin that could be coupled to Sepharose. The resultant affinity matrix bound asialoglycoproteins, and these could be quantitatively eluted with disaccharide haptens. The carboxyamidomethylated-galaptin-Sepharose affinity matrix was used to search for endogenous ligands in 13-day-rat lung. Cytosolic fractions of developing rat lung contained no moieties that could be specifically eluted with disaccharide hapten. Only when membranous fractions were extracted with 1% Triton were glycoproteins solubilized that bound to the affinity matrix and could be specifically eluted with disaccharide hapten. The eluted glycoproteins were potent inhibitors of galaptin binding to asialo-orosomucoid. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis identified these glycoproteins as being of high Mr, with three components of Mr 160000-200000 and a smaller component of Mr 75000. This is the first evidence for specific membrane-associated glycoproteins being the ligands of rat lung galaptin.

scholarly journals Transcriptional regulation of tropoelastin expression in rat lung fibroblasts: changes with age and hyperoxia

1998 ◽  
Vol 274 (6) ◽  
pp. L940-L950 ◽  
Author(s):  
Margaret C. Bruce ◽  
Catherine E. Honaker
Keyword(s):  
Gene Expression ◽  
Developmental Regulation ◽  
Fold Increase ◽  
Postnatal Period ◽  
Lung Fibroblasts ◽  
Elastic Fibers ◽  
Rat Lung ◽  
Structural Support ◽  
Hyperoxic Exposure ◽  
Septal Development

Elastic fibers are thought to provide structural support for secondary septa as the lung undergoes the transition from the saccular to the alveolar stage. The synthesis of the soluble precursor of elastin, tropoelastin, occurs during a finite developmental period. We have investigated the developmental regulation of tropoelastin gene transcription and mRNA expression in fetal and postnatal rat lung fibroblasts and have assessed the changes in tropoelastin gene expression caused by hyperoxic exposure during secondary septal development. With the use of an RT-PCR assay and intron-specific primers to detect heterogeneous nuclear RNA (hnRNA) and intron-spanning primers to detect mRNA in freshly isolated rat lung fibroblasts, tropoelastin gene expression was found to be upregulated late in gestation. From days 18 to 21 of gestation, there was a 4.5-fold increase in tropoelastin hnRNA ( P < 0.0001) and a 6-fold increase in mRNA ( P = 0.002). After birth, tropoelastin expression was downregulated. Signals decreased from fetal day 21 to postnatal day 2 for both tropoelastin hnRNA ( P = 0.021) and mRNA ( P = 0.043). Tropoelastin hnRNA decreased further from days 2 to 6 ( P= 0.04). Both tropoelastin hnRNA and mRNA were again upregulated during alveolarization from days 9 to 11, indicating that, once upregulated, transcription of the tropoelastin gene is not constant but varies with fetal and postnatal age. Exposure to >95% oxygen, when initiated on postnatal day 2 or 3 and continued until day 11, significantly diminished the developmental increase in tropoelastin hnRNA ( P < 0.005) and mRNA ( P < 0.05) normally seen on days 9– 11, indicating that the postnatal upregulation of tropoelastin gene expression is inhibited by hyperoxic exposure in the early postnatal period.

Rat lung lectin gene expression is regulated developmentally and by dexamethasone

1989 ◽  
Vol 256 (3) ◽  
pp. C501-C505 ◽  
Author(s):  
L. B. Clerch ◽  
P. Whitney ◽  
D. Massaro
Keyword(s):  
Gene Expression ◽  
Blot Analysis ◽  
Developmental Regulation ◽  
Single Gene ◽  
Translational Efficiency ◽  
Rat Lung ◽  
Dexamethasone Treatment ◽  
Developmentally Regulated ◽  
Lectin Gene ◽  
Mrna Concentration

The cell-agglutinating activity of soluble beta-galactoside-binding proteins (lectins) is developmentally regulated in several mammalian organs. Little is known of the alterations in gene expression that underlie this developmental regulation. Rat lung contains a dimeric beta-galactoside-binding protein that exhibits a postnatal peak of hemagglutination activity caused in part by an increased rate of lectin synthesis. We now report rat lung lectin mRNA concentration increased to a peak at age 6 days; dexamethasone treatment aborted this increase. Southern blot analysis is compatible with the presence of more than one lectin gene. However, two lines of evidence indicate that we measured a single gene product: 1) only one lectin of subunit Mr 14,000 is present in rat lung (Biochemistry 27: 692-699, 1988), and 2) in Northern blot analysis of RNA, the lectin cDNA hybridized with only one mRNA species. Our present findings, taken with prior studies of lectin synthesis, indicate that the postnatal increase in lectin synthesis is mediated pretranslationally and by an increased efficiency of translation. Dexamethasone treatment impairs the increase of lectin mRNA concentration but increases translational efficiency.

Plasma Components which Interfere with Ristocetin-induced Platelet Aggregation

1975 ◽  
Vol 33 (03) ◽  
pp. 540-546 ◽  
Author(s):  
Robert F Baugh ◽  
James E Brown ◽  
Cecil Hougie
Keyword(s):  
Platelet Aggregation ◽  
Human Plasma ◽  
Plasma Proteins ◽  
Binding Protein ◽  
Plasma Heating ◽  
Protein S ◽  
Fold Increase ◽  
Normal Human Plasma ◽  
Preliminary Examination ◽  
Normal Human

SummaryNormal human plasma contains a component or components which interfere with ristocetin-induced platelet aggregation. Preliminary examination suggests a protein (or proteins) which binds ristocetin and competes more effectively for ristocetin than do the proteins involved in ristocetin-induced platelet aggregation. The presence of this protein in normal human plasma also prevents ristocetin-induced precipitation of plasma proteins at levels of ristocetin necessary to produce platelet aggregation (0.5–2.0 mg/ml). Serum contains an apparent two-fold increase of this component when compared with plasma. Heating serum at 56° for one hour results in an additional 2 to 4 fold increase. The presence of a ristocetin-binding protein in normal human plasma requires that this protein be saturated with ristocetin before ristocetin-induced platelet aggregation will occur. Variations in the ristocetin-binding protein(s) will cause apparent discrepancies in ristocetin-induced platelet aggregation in normal human plasmas.

Detection and characterization of a heat and acid stable progesterone binding protein in the rat lung

1984 ◽  
Vol 104 (4_Supplb) ◽  
pp. S91-S92
Author(s):  
G. DAXENBICHLER ◽  
E. H. MOSER
Keyword(s):  
Binding Protein ◽  
Rat Lung ◽  
Acid Stable

ChemInform Abstract: Measurement of the Absolute Rate of 1,2-Hydrogen Migration in Benzylchlorocarbene

ChemInform ◽  
1989 ◽  
Vol 20 (47) ◽  
Author(s):  
J. E. JACKSON ◽  
N. SOUNDARARAJAN ◽  
W. WHITE ◽  
M. T. H. LIU ◽  
R. BONNEAU ◽  
...  
Keyword(s):  
Absolute Rate ◽  
Hydrogen Migration ◽  
The Absolute
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