Subcellular localization in normal and vitamin A-deficient rat liver of vitamin A serum transport proteins, albumin, ceruloplasmin and class I major histocompatibility antigens

Rask, Lars; Valtersson, Conny; Anundi, Helena; Kvist, Sune; Eriksson, Ulf; Dallner, Gustav; Peterson, Per A.

doi:10.1016/0014-4827(83)90112-x

Cited by 44 publications

(16 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…RBP in rat liver in both normal and retinol-deficient The moderate rates of RBP secretion observed with animals have suggested that the block in RBP secretion untreated retinol-deficient cells were greater than ini-found in retinol deficiency occurs at a site before the tially expected by us. This observation highlights the RBP molecule reaches the major portion of the Golgi fact, also evident from in vivo studies (Goodman, 1984;apparatus (Harrison et al, 1979apparatus (Harrison et al, , 1980Smith et al, Muto et al, 1972;Smith et al, 19731, that in retinol 1980;Rask et al, 1983). Other studies by Rask et al deficiency the specific inhibition of RBP secretion by the (1983) and by Ronne et al (1983) suggested that the hepatocyte is only a partial one.…”

Section: Discussionmentioning

confidence: 71%

Studies on the metabolism of retinol‐binding protein by primary hepatocytes from retinol‐deficient rats

Dixon

Goodman

1987

Journal Cellular Physiology

View full text Add to dashboard Cite

Studies were conducted to explore the regulation of retinol-binding protein (RBP) metabolism in cultured primary hepatocytes from retinol-deficient rats. Newly isolated hepatocytes from retinol-deficient rats contained elevated levels (3.4-fold) of RBP, compared to hepatocytes from normal (retinol-adequate) rats. Addition of retinol to retinol-depleted hepatocytes stimulated RBP secretion by the cells in a concentration-dependent manner. Maximal sitmulation of RBP secretion was seen with a retinol level of 0.3 pglml. The effect of retinol was quite rapid, and was evident by 20 minutes after addition of retinol to the medium. Stimulation of RBP secretion was only seen during the first few hours after retinol addition. The effect of retinol was specific for RBP; thus, retinol had n o effect on the secretion rates of transthyretin or albumin. Addition of retinoic acid also stimulated RBP secretion by retinol-deficient hepatocytes. Addition of dexamethasone to retinol-deficient cells did not maintain the initial rate of RBP secretion. Dexamethasone also had no effect on the secretion of transthyretin o r albumin by these cells. The effects of retinol and of dexamethasonc sccn here with retinol-depleted cells differed dramatically from effects seen in other studies with normal (retinol-adequate) hepatocytes. Thus, with normal cells, dexarnethasone maintains RBP, TTR, and albumin production and secretion rates close to initial rates. Also in normal hepatocytes, with ample retinol available within t h e cell, addition of exogenous retinol does not appear to influence RBP secretion. In contrast, and as shown previously in intact rats, in retinol deficiency the availability of retinol specifically regulates the secretion of RBP by hepatocytes.Retinol is transported normally in plasma bound to a al., 1985). Glucocorticoid hormones specifically stimuspecific transport protein, retinol-binding protein (RBP) lated a 2-3-fold increase in the net accumulation (syn-(see Goodman, 1984, for recent review and references). thesis) of RBP by H4 cells (Borek et al., 1981). The effects RBP is a single polypeptide which is secreted by the of glucocorticoid hormones and of retinol were indepenliver mainly as a 1 : l molar retinol-RBP complex (holo-dent of each other. RBP) and which circulates in plasma mainly as a proThe rates of RBP synthesis and secretion by H4 cells tein-protein complex with plasma transthyretin (TTR). are quite low, more than a n order of magnitude less Retinol must be available to the liver in order for RBP than the rates observed in vivo. Recently, we conducted secretion to be maintained. Thus, studies in rats have studies on RBP metabolism and its regulation with culshown that RBP secretion from liver is specifically in-tured primary hepatocytes obtained from normal rats hibited during retinol deficiency, and that repletion of (companion paper, Dixon and Goodman, 1986). Major deficient rats with retinol rapidly and specifically stim-differences were found between H4 cells and normal ulates RBP release (Goodman, 1...

show abstract

Section: Discussionmentioning

confidence: 71%

Studies on the metabolism of retinol‐binding protein by primary hepatocytes from retinol‐deficient rats

Dixon

Goodman

1987

Journal Cellular Physiology

View full text Add to dashboard Cite

show abstract

“…In contrast to many other ligands that are transferred to lysosomes after processing in endosomes, retinol is transferred to the endoplasmic reticulum (14), where retinol-binding protein (RBP) is found in high concentration. Binding of retinol to RBP apparently initiates a translocation of retinol-RBP to the Golgi complex, followed by secretion of retinol-RBP from the cells (15) (Fig. 2).…”

Section: Tissue Uptake Of Chylomicron Remnantsmentioning

confidence: 97%

“…Essentially all of the retinol in the plasma that is not associated with chylomicrons and their remnants is bound to RBP and must be mobilized from stellate cells to the plasma retinol-RBP pool. Because cultured hepatocytes synthesize RBP and secrete retinol-RBP (15), it was suggested that the hepatocytes were the exclusive site of retinol mobilization from the liver. However, recent studies have shown that stellate cells also contain RBP (18,22) and cultured stellate cells from rat liver secrete retinol bound to RBP.…”

Section: The Role Of Stellate Cellsmentioning

confidence: 99%

Transport and Storage of Vitamin A

Blomhoff

Green

Berg

et al. 1990

Science

563

309

View full text Add to dashboard Cite

The requirement of vitamin A (retinoids) for vision has been recognized for decades. In addition, vitamin A is involved in fetal development and in the regulation of proliferation and differentiation of cells throughout life. This fat-soluble organic compound cannot be synthesized endogenously by humans and thus is an essential nutrient; a well-regulated transport and storage system provides tissues with the correct amounts of retinoids in spite of normal fluctuations in daily vitamin A intake. An overview is presented here of current knowledge and hypotheses about the absorption, transport, storage, and metabolism of vitamin A. Some information is also presented about a group of ligand-dependent transcription factors, the retinoic acid receptors, that apparently mediate many of the extravisual effects of retinoids.

show abstract

“…Isolation of temperature-sensitive yeast mutants defective in export of both membranebound and secreted protein from the ER has established that a common biochemical basis regulates trafficking from this organelle to the cis-Golgi (Novick et al, 1981). Comparative studies defining differences in the kinetics of transport of a variety of membranebound secreted proteins (Fries et al, 1984;Ledford and Davis, 1983;Scheele and Tartakoff, 1985;Sege et al, 1981;Yeo et al, 1985), altered secretion of genetically engineered mutant proteins (Emr et al, 1984;Gallione and Rose, 1985;Rose and Bergman, 1982), and the requirement for cofactors (Rask et al (1983) or quaternary interactions (Kreis and Lodish, 1986;Kvist et al, 1982;Mains and Sibley, 1982;Owen et al, 1980;Sege et al, 1981) for export suggest that signals encoded in the primary sequence of a protein provide information, facilitating an initial step in interaction with this common transport machinery. Accordingly, different models have been proposed to explain the relative rate of exit of secretory proteins from the ER.…”

Section: Transport Of Secretory Proteins In the Er And Their Transfermentioning

confidence: 99%

Secretory pathways in animal cells: With emphasis on pancreatic acinar cells

Beaudoin

Grondin

1991

J. Elec. Microsc. Tech.

View full text Add to dashboard Cite

Studies over the past three decades have clearly established the existence of at least two distinct pathways for the intracellular transport and release of secretory proteins by animal cells. These have been identified as the regulated and constitutive pathways. Many observations have indicated that in certain cells, such as those of the exocrine pancreas and parotid glands at least, these pathways coexist in the same cells. Although the general scheme of protein transport within these pathways is well established, many fundamental aspects of intracellular transport remain to be unraveled. How are proteins transported through the endoplasmic reticulum? How are the transitional vesicles formed and what are the underlying mechanisms involved in their fusion with the cis-Golgi cisterna? Even the general mode of transfer through the Golgi stack is debated: Is there a diffusion through the stack by flow through intercisternal tubules and openings or is there a vesicle transfer system where membrane quanta hop from one cisterna to the other? What is the fate of secretory proteins in the trans-Golgi area and by what mechanisms is a fraction of newly synthesized molecules of a given secretory protein released spontaneously while the majority of such nascent molecules are diverted into a secretory granule compartment? In this review, we have examined these and other aspects of intracellular transport of secretory proteins using pancreatic acinar cells as our reference model and we present some evidence to support the existence of a paragranular pathway of secretion associated with secretory granule maturation.

show abstract

Subcellular localization in normal and vitamin A-deficient rat liver of vitamin A serum transport proteins, albumin, ceruloplasmin and class I major histocompatibility antigens

Cited by 44 publications

References 36 publications

Studies on the metabolism of retinol‐binding protein by primary hepatocytes from retinol‐deficient rats

Studies on the metabolism of retinol‐binding protein by primary hepatocytes from retinol‐deficient rats

Transport and Storage of Vitamin A

Secretory pathways in animal cells: With emphasis on pancreatic acinar cells

Contact Info

Product

Resources

About