The asialoglycoprotein receptor: relationships between structure, function, and expression

1995 ◽  
Vol 75 (3) ◽  
pp. 591-609 ◽  
Author(s):  
R. J. Stockert
Keyword(s):  
Translational Regulation ◽  
Chemotherapeutic Agents ◽  
Asialoglycoprotein Receptor ◽  
Receptor Expression ◽  
Coated Pits ◽  
Receptor Mediated Endocytosis ◽  
Intracellular Compartments ◽  
Foreign Genes ◽  
And Function ◽  
A Site

Transport of macromolecules into the cell by receptor-mediated endocytosis follows a complex series of intracellular transfers, passing through distinct environments. The asialoglycoprotein receptor is a prototype of the class of receptors that constitutively enters cells via coated pits and delivers ligand to these intracellular compartments. In addition to being a model of receptor-mediated endocytosis, the presence of the receptor on hepatocytes provides a membrane-bound active site for cell-to-cell interactions, has made possible the selective targeting of chemotherapeutic agents and foreign genes, and has also been implicated as a site mediating hepatitis B virus uptake. Regulated expression of receptor subunits and their intracellular trafficking during biosynthesis and endocytosis has provided insights into the relationship of receptor structure to its overall function. As a marker of hepatocellular differentiation, its study has uncovered a unique response to intracellular guanosine 3',5'-cyclic monophosphate and translational regulation of the receptor. In this review, an overview of these diverse findings is provided in an attempt to relate the various aspects of structure and function as they impact on receptor expression.

Ultrastructural study of cytoskeletal interactions with endosomes in macrophages by quickfreezing and deep-etching method

1990 ◽  
Vol 48 (3) ◽  
pp. 576-577
Author(s):  
Takeshi Baba ◽  
Nobuki Shiozawa ◽  
Masao Hotch ◽  
Shinichi Ohno
Keyword(s):  
Immune Complex ◽  
Ultrastructural Study ◽  
Fc Receptor ◽  
Coated Pits ◽  
Deep Etching ◽  
Receptor Mediated Endocytosis ◽  
Etching Method ◽  
Quick Freezing

Endosomes are vesicular or tubular organelles that play important roles in transports of receptors and receptor―bound ligands during receptor-mediated endocytosis. The mechanisms of endocytic transports from clathrin-coated pits to lysosomes have been studied by many investigators. However, few studies were reported about the interactions between endosomes and cytoskeletons. In this study, Fc-receptor-mediated endocytosis in macrophages are investigated by quick-freezing and deep-etching (QF-DE) method combined with gold-labeled immune complex and “replica scraping method”.

Role of the 807 C/T Polymorphism of the α2 Gene in Platelet GP Ia Collagen Receptor Expression and Function

1999 ◽  
Vol 81 (06) ◽  
pp. 951-956 ◽  
Author(s):  
J. Corral ◽  
R. González-Conejero ◽  
J. Rivera ◽  
F. Ortuño ◽  
P. Aparicio ◽  
...  
Keyword(s):  
Venous Thrombosis ◽  
Cell Types ◽  
Receptor Expression ◽  
Case Control Studies ◽  
Platelet Surface ◽  
Vitro Analysis ◽  
And Function ◽  
In Vitro Analysis

SummaryThe variability of the platelet GP Ia/IIa density has been associated with the 807 C/T polymorphism (Phe 224) of the GP Ia gene in American Caucasian population. We have investigated the genotype and allelic frequencies of this polymorphism in Spanish Caucasians. The T allele was found in 35% of the 284 blood donors analyzed. We confirmed in 159 healthy subjects a significant association between the 807 C/T polymorphism and the platelet GP Ia density. The T allele correlated with high number of GP Ia molecules on platelet surface. In addition, we observed a similar association of this polymorphism with the expression of this protein in other blood cell types. The platelet responsiveness to collagen was determined by “in vitro” analysis of the platelet activation and aggregation response. We found no significant differences in these functional platelet parameters according to the 807 C/T genotype. Finally, results from 3 case/control studies involving 302 consecutive patients (101 with coronary heart disease, 104 with cerebrovascular disease and 97 with deep venous thrombosis) determined that the 807 C/T polymorphism of the GP Ia gene does not represent a risk factor for arterial or venous thrombosis.

P2 receptor expression signaling and function in osteoclasts

10.2741/s214 ◽  
2011 ◽  
Vol S3 (3) ◽  
pp. 1101-1118
Author(s):  
S. Jeffrey Dixon
Keyword(s):  
Receptor Expression ◽  
P2 Receptor ◽  
And Function

Asking More than Where: Developing a Site Contextual Model Based on Reconstructing past Environments

1997 ◽  
Vol 17 (4) ◽  
pp. 307-336
Author(s):  
Douglas S. Frink
Keyword(s):  
Native American ◽  
Phase I ◽  
Contextual Model ◽  
Model Based ◽  
European Settlement ◽  
Level Data ◽  
Limited Application ◽  
And Function ◽  
A Site ◽  
Phase Ii And Iii

Contract archaeology accounts for the majority of archaeological studies conducted in Vermont. As these studies serve the development community, the focus of investigation has been to identify and avoid sites, not to research and evaluate the information they contain. Native-American site locational models have limited application because they are based primarily on the landforms' proximity to water. The Archaeology Consulting Team is developing a contextual model based on reconstructing the pre-European settlement environment. Hypotheses comparing expected size and function of Native-American sites in different environments can be posed at the Phase I level of archaeological studies. Furthermore, with Phase I level data, these hypotheses can provide the framework for research designs at Phase II and III levels of archaeological study.

scholarly journals Differential Regulation of Gonadotropins as Revealed by Transcriptomes of Distinct LH and FSH Cells of Fish Pituitary

2021 ◽  
Vol 22 (12) ◽  
pp. 6478
Author(s):  
Lian Hollander-Cohen ◽  
Matan Golan ◽  
Berta Levavi-Sivan
Keyword(s):  
Follicle Stimulating Hormone ◽  
Differential Regulation ◽  
Receptor Expression ◽  
Hormone Regulation ◽  
Fish Reproduction ◽  
Cell Type ◽  
Conserved Genes ◽  
Transgenic Tilapia ◽  
And Function ◽  
Direct Regulation

From mammals to fish, reproduction is driven by luteinizing hormone (LH) and follicle-stimulating hormone (FSH) temporally secreted from the pituitary gland. Teleost fish are an excellent model for addressing the unique regulation and function of each gonadotropin cell since, unlike mammals, they synthesize and secrete LH and FSH from distinct cells. Only very distant vertebrate classes (such as fish and birds) demonstrate the mono-hormonal strategy, suggesting a potential convergent evolution. Cell-specific transcriptome analysis of double-labeled transgenic tilapia expressing GFP and RFP in LH or FSH cells, respectively, yielded genes specifically enriched in each cell type, revealing differences in hormone regulation, receptor expression, cell signaling, and electrical properties. Each cell type expresses a unique GPCR signature that reveals the direct regulation of metabolic and homeostatic hormones. Comparing these novel transcriptomes to that of rat gonadotrophs revealed conserved genes that might specifically contribute to each gonadotropin activity in mammals, suggesting conserved mechanisms controlling the differential regulation of gonadotropins in vertebrates.

scholarly journals Efficient IL-2R signaling differentially affects the stability, function, and composition of the regulatory T-cell pool

2021 ◽  
Author(s):  
Marc Permanyer ◽  
Berislav Bošnjak ◽  
Silke Glage ◽  
Michaela Friedrichsen ◽  
Stefan Floess ◽  
...  
Keyword(s):  
T Cell ◽  
Treg Cell ◽  
Cell Function ◽  
Interleukin 2 ◽  
Foxp3 Expression ◽  
Treg Cells ◽  
Receptor Expression ◽  
Spontaneous Mutant ◽  
Cell Pool ◽  
And Function

AbstractSignaling via interleukin-2 receptor (IL-2R) is a requisite for regulatory T (Treg) cell identity and function. However, it is not completely understood to what degree IL-2R signaling is required for Treg cell homeostasis, lineage stability and function in both resting and inflammatory conditions. Here, we characterized a spontaneous mutant mouse strain endowed with a hypomorphic Tyr129His variant of CD25, the α-chain of IL-2R, which resulted in diminished receptor expression and reduced IL-2R signaling. Under noninflammatory conditions, Cd25Y129H mice harbored substantially lower numbers of peripheral Treg cells with stable Foxp3 expression that prevented the development of spontaneous autoimmune disease. In contrast, Cd25Y129H Treg cells failed to efficiently induce immune suppression and lost lineage commitment in a T-cell transfer colitis model, indicating that unimpaired IL-2R signaling is critical for Treg cell function in inflammatory environments. Moreover, single-cell RNA sequencing of Treg cells revealed that impaired IL-2R signaling profoundly affected the balance of central and effector Treg cell subsets. Thus, partial loss of IL-2R signaling differentially interferes with the maintenance, heterogeneity, and suppressive function of the Treg cell pool.

scholarly journals Therapeutic Application of Brain-Specific Angiogenesis Inhibitor 1 for Cancer Therapy

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3562
Author(s):  
Mitra Nair ◽  
Chelsea Bolyard ◽  
Tae Jin Lee ◽  
Balveen Kaur ◽  
Ji Young Yoo
Keyword(s):  
Angiogenesis Inhibitor ◽  
Suppressor Gene ◽  
Chemotherapeutic Agents ◽  
Tumor Models ◽  
In Vivo Models ◽  
Herpes Simplex Viruses ◽  
Multiple Tumor ◽  
And Function

Brain-specific angiogenesis inhibitor 1 (BAI1/ADGRB1) is an adhesion G protein-coupled receptor that has been found to play key roles in phagocytosis, inflammation, synaptogenesis, the inhibition of angiogenesis, and myoblast fusion. As the name suggests, it is primarily expressed in the brain, with a high expression in the normal adult and developing brain. Additionally, its expression is reduced in brain cancers, such as glioblastoma (GBM) and peripheral cancers, suggesting that BAI1 is a tumor suppressor gene. Several investigators have demonstrated that the restoration of BAI1 expression in cancer cells results in reduced tumor growth and angiogenesis. Its expression has also been shown to be inversely correlated with tumor progression, neovascularization, and peri-tumoral brain edema. One method of restoring BAI1 expression is by using oncolytic virus (OV) therapy, a strategy which has been tested in various tumor models. Oncolytic herpes simplex viruses engineered to express the secreted fragment of BAI1, called Vasculostatin (Vstat120), have shown potent anti-tumor and anti-angiogenic effects in multiple tumor models. Combining Vstat120-expressing oHSVs with other chemotherapeutic agents has also shown to increase the overall anti-tumor efficacy in both in vitro and in vivo models. In the current review, we describe the structure and function of BAI1 and summarize its application in the context of cancer treatment.

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