Sorting and transepithelial transport of adsorbed protein tracers: Effects of temperature

Wilson, Jean M.; King, Barry F.

doi:10.1002/ar.1092160106

Cited by 5 publications

(2 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Presumably, the destruction of immunoglobulins is avoided because of the specificity of this enzyme. The results in Figure 6D suggest that pepF accompanies endocytosed materials into the visceral endoderm [49]. Indeed, the environment (lower pH) of the endocytotic vesicles and secondary lysosomes is probably more conducive to the enzymatic activity of pepF as aspartic proteinases tend to function optimally in acidic conditions.…”

Section: Discussionmentioning

confidence: 95%

An Aspartic Proteinase Expressed in the Yolk Sac and Neonatal Stomach of the Mouse1

Chen¹,

Rosenfeld²,

Roberts³

et al. 2001

Biology of Reproduction

View full text Add to dashboard Cite

A murine aspartic proteinase, described herein, is intermediate in amino acid sequence identity between the placentally produced pregnancy-associated glycoproteins (PAGs) and gastric pepsins. While PAGs are secreted products of placental trophoblast tissue of ungulates and most are not believed to function proteolytically, pepsins are digestive enzymes. The cDNA for this aspartic proteinase was amplified by reverse transcription-polymerase chain reaction from RNA extracted from murine placentas and neonatal stomachs. The open reading frame encoded a 387-amino acid polypeptide with a 15-residue signal sequence. The enzyme most resembled pepsinogen F (a protein identified in the stomachs of neonatal rabbits and rats) and PAG-like proteins cloned from equine and feline placentae. In the stomach, both its mRNA and protein were expressed in gastric chief cells of preweaned neonates. Within the placenta, its mRNA was present in both the parietal and visceral yolk sacs. However, the protein was most prevalent in the visceral yolk sac, with little detectable in the parietal yolk sac. The recombinant protein was expressed in Escherichia coli. This protein was capable of self-activation and exhibited proteolytic activity toward casein. The presence of this enzyme in two organs involved in the selective transcellular transport of proteins suggests that it has specialized digestive functions.

show abstract

Section: Discussionmentioning

confidence: 95%

An Aspartic Proteinase Expressed in the Yolk Sac and Neonatal Stomach of the Mouse1

Chen¹,

Rosenfeld²,

Roberts³

et al. 2001

Biology of Reproduction

View full text Add to dashboard Cite

show abstract

“…Thus, endocytosis of this type has been suggested to participate in the reabsorption of uterine fluid from the lumen (Enders & Nelson, 1973;Parr & Parr, 1974, 1977. However, because mannose-specific binding sites for horseradish peroxidase have been described for various cells in the rat (Straus, 1983;Wilson & King, 1986), internalization of this protein might be more specific than previously considered. Nevertheless, these observations demonstrate a transcellular pathway through which proteins synthesized and secreted by the conceptus, such as ovine and bovine trophoblast protein I, might be transferred from the luminal to endometrial extracellular fluid.…”

Section: Uptake and Release By Endometrial And Embryonic Cellsmentioning

confidence: 99%

The blood-uterine lumen barrier and exchange between extracellular fluids

McRae¹

1988

Reproduction

View full text Add to dashboard Cite

Summary. The concept of a blood-tissue barrier defines the rates at which matter exchanges among the vascular and extravascular fluids of the tissue. The remarkably slow rates at which substances such as mannitol ( M , 182) enter uterine fluid from plasma demonstrate the existence of a blood-uterine lumen barrier. Available evidence indicates that the uterine microvascular endothelium and the uterine epithelium behave as lipoid layers interrupted by water-filled channels. Furthermore, both cell layers appear to select actively certain substances over others for exchange with opposing extracellular fluids. In contrast to these similarities, the uterine epithelium and endothelium differ considerably with regard to restrictiveness. For most substances the primary rate-limiting boundary between blood and the uterine lumen is the epithelium. The extracellular fluid compartments of the lumen and endometrium are also influenced by the internalization and release of materials into and out of intracellular compartments including those of the stromal and migratory cells of the endometrium, the epithelium and the developing conceptus. Considerable evidence suggests that the luminal milieu of the developing embryo is created and maintained by the transport and permeability properties o r the blood-uterine lumen barrier in conjunction with the cellular activities of the endometrium and embryo. This milieu probably fulfils the informational and nutritional needs of the developing embryo.

show abstract

Development, morphology, and function of the yolk‐sac placenta of laboratory rodents

1990

View full text Add to dashboard Cite

A review of current knowledge of the unusual structure and several functions of the yolk-sac membranes of common laboratory rodents, viz., rats, mice, hamsters, guinea pigs and gerbils, enables a better assessment of the significance of this maternofetal exchange system in the experimental production of congenital anomalies. The anatomy of both visceral and parietal walls of the rodent yolk-sac placenta--specifically the anatomical relationships of each wall with maternal and with other fetal tissues--depends on the mode of origin and subsequent development of the yolk sac in these several species. Accordingly, the developmental biology of the rodent yolk sac is described. Since both fine structure and anatomical relationships also determine in large measure the functioning of the membrane as a whole in the absorption of selected materials either for intracellular digestion or for cellular translocation and transport to the developing embryo, the anatomy of the yolk sac is considered in detail. Similarly, since available evidence strongly suggests that teratogenic agents induce perturbations in the cellular mechanisms that control these several functions of the yolk-sac placental system in the production of birth defects, additionally an account is given of the cell biology of the membrane, i.e., endocytosis and targeting/trafficking of materials either for digestion within the epithelium at the maternal surface of the visceral yolk sac or for translocation across the yolk-sac membrane as a whole.

show abstract

Sorting and transepithelial transport of adsorbed protein tracers: Effects of temperature

Cited by 5 publications

References 28 publications

An Aspartic Proteinase Expressed in the Yolk Sac and Neonatal Stomach of the Mouse1

An Aspartic Proteinase Expressed in the Yolk Sac and Neonatal Stomach of the Mouse1

The blood-uterine lumen barrier and exchange between extracellular fluids

Development, morphology, and function of the yolk‐sac placenta of laboratory rodents

Contact Info

Product

Resources

About