Solubilization and characterization of the chicken oocyte vitellogenin receptor

Stifani, Stefano; George, Rajan; Schneider, Wolfgang J.

doi:10.1042/bj2500467

Cited by 107 publications

(61 citation statements)

References 30 publications

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“…In the present study, the same endocytic coated vesicles were found in the oocytes, but only of yellow follicles. On the other hand, Stifani et al (1988) have succeeded in identifying the VTG receptor in chicken oocytes of yellow follicles. Then there might be two different mechanisms for the uptake of nutrients in avian oocytes.…”

Section: Discussionmentioning

confidence: 99%

Vitellogenin Transport and Yolk Formation in the Quail Ovary

et al. 2003

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Section: Discussionmentioning

confidence: 99%

Vitellogenin Transport and Yolk Formation in the Quail Ovary

et al. 2003

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“…VLDL was labeled with 125 I to a specific activity of 250 -400 cpm/ng using the iodine monochloride method as described previously (22). Vitellogenin was purified from plasma of estrogen-treated roosters by ion exchange chromatography (DEAE-cellulose) as described (23). Recombinant RAP was produced as a glutathione S-transferase (GST) fusion protein using a pGEX 2T-derived (Pharmacia Biotech Inc.) expression plasmid in DH5␣ bacteria (13).…”

Section: Methodsmentioning

confidence: 99%

Receptor-associated Protein and Members of the Low Density Lipoprotein Receptor Family Share a Common Epitope

Hiesberger

Hodits

Ullrich

et al. 1996

Journal of Biological Chemistry

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Receptor-associated-protein (RAP) 1 was initially described as a 39 -40-kDa protein copurifying with LDL receptor (LDLR)-related protein (LRP) (1, 2). At the same time, a putative target antigen in Heymann nephritis (HN), an experimental rat model of human membranous nephropathy, was identified and cloned (3). On molecular characterization of RAP, it became evident that the protein identified as the target antigen in HN was identical to RAP and not, as previously assumed, a fragment of glycoprotein 330/megalin (4). RAP subsequently was shown to bind not only to LRP but also to other members of the LDLR family, including megalin (5), the VLDLR (6), the chicken oocyte receptor for VLDL and vitellogenin (LR8) (7,8) and, to a lesser extent, to the LDLR itself (8, 9). The ability to interfere with ligand binding to these receptors has made RAP a perfect tool to study ligand-receptor interaction both in vitro (8, 10 -14) and in vivo (15). The latter experiments especially have established the role of LRP as a chylomicron remnant receptor in the liver. Despite the successful use of RAP to study the physiological function(s) of members of the LDLR family and of LRP in particular, clues about the function of RAP in vivo emerged only recently. The tetrapeptide sequence HNEL at the carboxyl terminus of RAP was shown to be necessary for the retention of RAP in the endoplasmic reticulum; thus, RAP associates in vivo with LRP early in the secretory pathway and dissociates from the receptor before reaching the cell surface (16). These results suggested a specialized role of RAP as a chaperon for LRP, possibly regulating the interaction of the receptor with ligands along the secretory pathway. This was confirmed by elegant studies by Herz and colleagues in RAP knockout mice (17) and in cultured cells in experiments relating the biosynthesis and functional expression of LRP and megalin with that of RAP (18). These experiments show that at least one of the physiological functions of RAP can be defined as that of a specialized escort protein, which protects certain receptors from ligand-induced aggregation along their intracellular itinerary. We have previously shown that LR8 can serve as a model system to study ligand binding and structural aspects of LDLR family members (8,19,20). Here we have used LR8 to demonstrate that all receptors that strongly bind RAP share a common immunological epitope with the escort protein. Based on this observation, we propose a model for the development of passive Heymann nephritis induced by anti-RAP antibodies, in which megalin present in the brush borders of the proximal kidney tubule in rats constitutes an additional target antigen. EXPERIMENTAL PROCEDURESPreparation and Radiolabeling of Ligands-VLDL was prepared from plasma of estrogen-treated roosters by sequential ultracentrifugation according to the method of George et al. (21). VLDL was labeled with 125 I to a specific activity of 250 -400 cpm/ng using the iodine

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“…4444 (Bernardi and Cook, 1960;Stifani et al, 1988;Wallace, 1985). In laying domestic hens (Gallus gallus domesticus), approximately 50% of the liver's daily protein synthesis is attributed to VTG production, potentially tripling the amount of protein in circulation (Gruber, 1972).…”

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The metabolic cost of avian egg formation: possible impact of yolk precursor production?

Vézina

Salvante

Williams

2003

Journal of Experimental Biology

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Physiological mechanisms underlying one of the major assumptions of life history theory, namely that an increased effort in current reproduction may have a negative impact on future reproductive success, are not well understood (Stearns, 1992). One reason for this lack of knowledge is that, in avian systems, most of the research attention has been focused on manipulations of reproductive effort at the incubation or chickprovisioning stages (Monaghan and Nager, 1997) and, thus, the potential physiological costs incurred earlier in breeding, i.e. during follicle development and egg production, have received very little attention. Recent research, however, has shown that the energy cost of egg production in birds may be significant Vézina and Williams, 2002). We recently showed that the physiological process of egg formation in female European starlings (Sturnus vulgaris) is responsible for a 22% increase in resting metabolic rate (RMR) in laying individuals (Vézina and Williams, 2002). We further demonstrated that 18% of the variation in elevated laying RMR was explained by the maintenance and activity cost of the working oviduct (Vézina and Williams, 2003) and emphasized that this organ is probably costly enough that selection has led to a very tight size-function relationship, explaining its rapid pattern of recrudescence and regression. However, 82% of the variation in laying RMR remains unexplained, suggesting that other energy-consuming physiological mechanisms must be responsible, at least in part, for the metabolic cost of egg production (Vézina and Williams, 2003).Another component of egg production that is likely to be energetically costly is the increased liver activity involved in protein and lipid production for oogenesis. During the process of egg formation, the hypothalamus initiates a hormonal cascade by releasing gonadotropin-releasing hormone (GnRH), which induces the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the pituitary gland (Williams, 1998;Scanes, 2000). These hormones stimulate the ovary to produce estrogens (Williams, 1998), which then trigger the production of the egg-yolk precursors, vitellogenin (VTG) and yolk-targeted very-lowdensity lipoprotein (VLDLy), by the liver (Bergink et al., 1974;Deeley et al., 1975;Wallace, 1985;Walzem, 1996;Williams, 1998), which are then secreted into the blood. During rapid yolk development, plasma VTG and VLDLy are taken up by the ovary and are processed within the follicles into yolk, the nutrient and energy source for the developing avian embryo Little is known about the energy costs of egg production in birds. We showed in previous papers that, during egg production, European starlings (Sturnus vulgaris) undergo a 22% increase in resting metabolic rate (RMR) and that the maintenance and activity costs of the oviduct are responsible for 18% of the variation in elevated laying RMR. Therefore, other energy-consuming physiological mechanisms must be responsible for the remaining unexplained variation in elevated laying ...

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Solubilization and characterization of the chicken oocyte vitellogenin receptor

Cited by 107 publications

References 30 publications

Vitellogenin Transport and Yolk Formation in the Quail Ovary

Vitellogenin Transport and Yolk Formation in the Quail Ovary

Receptor-associated Protein and Members of the Low Density Lipoprotein Receptor Family Share a Common Epitope

The metabolic cost of avian egg formation: possible impact of yolk precursor production?

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