Disease relevance of Gypa

• We previously reported that YY-1, a versatile transcription factor, regulates expression of glycophorin gene by binding to its locus control region-like region (Gp-LCR) in combination with E-box binding protein during murine erythroleukemia (MEL) cell differentiation [1].
• In many respects, therefore, the biosynthesis of Band III resembles that of co-translationally-inserted proteins whose N-terminal portions are exposed on the exterior of the cell, like vesicular stomatitis virus glycoprotein, HLA-A antigens, and glycophorin [2].
• Although Mycoplasma pulmonis did not lyse normal erythrocytes, it rapidly lysed erythrocytes that had cytoskeletal deficiencies which allow increased diffusion of membrane glycophorin or that had been treated with trypsin to remove surface proteins [3].
• These results, taken together, suggest that most influenza C virus receptors on human erythrocytes, if not all, reside on glycophorin A which is known to possess the M or N blood group activity [4].
• Parasitemia increased exponentially after infection with Plasmodium berghei NK65, P. chabaudi, and P. vinckei in Duffy antigen knockout, glycophorin A knockout, and wild-type mice, indicating that the Duffy antigen and glycophorin A are not essential for these malaria parasites [5].

High impact information on Gypa

• Lymphocytes bind to membranes containing the addressin, but not to phospholipid bilayers or to control glycophorin-reconstituted membranes [6].
• Protein 4.1 forms a stable ternary complex with spectrin and actin, thereby strengthening the reticulum and anchoring it directly to the lipid bilayer or to another intrinsic protein, glycophorin [7].
• Cells of one clone, Cl.Ly23/4, specifically bind glycophorin from sheep erythrocytes (SRBC) [8].
• The liposomes were conjugated with either nonspecific mouse IgG, which interacts with an Fc receptor, or with monoclonal anti-human glycophorin, which interacts simultaneously with an Fc receptor and human glycophorin in the cell membrane [9].
• Efficacy of drug delivery with liposomes directed both to the Fc receptor and to glycophorin A was not reduced by human IgG or soluble antiglycophorin A, but it was reduced twofold in the presence of both soluble ligands [9].

Chemical compound and disease context of Gypa

• The glycophorin mRNA is induced during the differentiation of murine erythroleukemia cells with dimethyl sulfoxide [10].
• In immunofluorescent and in vitro translation studies, it was shown that glycophorin mRNA is absent in uninduced murine erythroleukemia (MEL) cells, but is induced in dimethylsulfoxide-treated differentiating cells [11].

Biological context of Gypa

• In addition, GPA monomers with varying degrees of glycosylation dimerized, providing clear evidence that carbohydrate structures on the extracellular domain do not affect dimerization [12].
• The purpose of this study was to directly examine the GPA-band 3 interaction in vivo and determine the nature of this association during erythroid membrane biogenesis [12].
• We chose glycophorin A (GPA) as a model integral protein to begin investigating protein-sorting mechanisms [13].
• The far upstream region (-1.2-0.9 kilobase pairs) of the mouse glycophorin gene contains the locus control region (LCR)-like region, which acts as an erythroid-specific enhancer dependent on chromosomal integration in murine erythroleukemia (MEL) cells [14].
• CONCLUSIONS: GPA-/- mice show apparently normal phenotypes at least during the early generations [15].

Anatomical context of Gypa

• Glycophorin A is the major transmembrane sialoglycoprotein of red blood cells [16].
• Based on these findings and other published evidence, we propose that band 3 plays a chaperone-like role, which is necessary for the recruitment of GPA to the red blood cell plasma membrane [16].
• We discovered that GPA was more connected to the membrane cytoskeleton, either directly or indirectly, in erythroblasts and young reticulocytes than in mature cells [13].
• Further, we suggest that the enhanced rigidity of reticulocyte membranes observed in earlier investigations results, at least in part, from increased connectivity of GPA with the spectrin-based skeleton [13].
• Erythrocyte membrane proteins reactive with IgG (warm-reacting) anti-red blood cell autoantibodies: II. Antibodies coprecipitating band 3 and glycophorin A [17].

Associations of Gypa with chemical compounds

• Lectin-binding and spontaneous capping characteristics of the thymocyte glycophorin-like glycoprotein [18].
• BACKGROUND: Glycophorin A (GPA) has a large number of sialic acid-containing oligosaccharide chains [15].
• The recognition by resident macrophages was effectively inhibited by N-acetylneuramin lactose, N-acetylneuraminic acid, glycophorin A, and disialoganglioside GD1a, but poorly by lactose, asialoglycophorin A, and monosialoganglioside GM1 [19].
• Sera and RBC eluates from the AIHA-positive mice immunoprecipitated a murine RBC autoantigen of 42,000 MW that comigrates with a zone of glycophorin in PAS-stained polyacrylamide gels [20].
• The recognition by thioglycollate-induced macrophages was not inhibited by glycophorin A but was partially inhibited by L-fucose, lactoferrin, and oligosaccharides from band 3 glycoprotein [19].

Physical interactions of Gypa

• One was region II which includes the erythrocyte binding domain of this parasite ligand which binds to its receptor glycophorin A [21].
• Inhibitory activity of the unlabeled glycophorin A against the labeled glycophorin A-binding was lowered by neuraminidase and Pronase treatment [22].

Regulatory relationships of Gypa

• Loss of rotational mobility of band 3 proteins in human erythrocyte membranes induced by antibodies to glycophorin A [23].

Other interactions of Gypa

• The monoclonal antibody TER-119 recognizes a molecule associated with glycophorin A and specifically marks the late stages of murine erythroid lineage [24].
• Mutation of tyrosine 569 to phenylalanine had no effect on the M-CSF-induced endocytosis of Fms, and a four-amino-acid sequence containing Y-569 could support endocytosis when transferred into the cytoplasmic juxtamembrane region of a glycophorin A construct [25].
• The fusion gene containing the mouse C receptor 1-related gene/protein y (Crry) and a single chain Ab fragment with specificity for mouse glycophorin A was placed under transcriptional control of a liver-specific promoter [26].
• The gene has been found to be encoded on four separate exons, and it thus differs from the cell surface mucin leukosialin, whose coding region is contained on one exon, but is similar to glycophorin and CD34, other cell surface mucins whose genes are divided into multiple coding exons [27].
• The results indicated that HRCs could be defined by their expression of both transferrin receptors and glycophorin A [28].

Analytical, diagnostic and therapeutic context of Gypa

• Using immunofluorescence microscopy and Western blotting we found that GPA sorted predominantly to reticulocytes [13].
• These results rule out a mechanism whereby band 3 rotational immobilization results from enhanced interactions with the membrane skeleton that are mediated by a conformational change in glycophorin A [23].
• Full length mouse glycophorin gene constructed using recombinant polymerase chain reaction [29].
• A preferential reaction of antibody J11A with MM over NN GPA was demonstrated by its reactions with enzyme-treated erythrocytes, its inhibition by purified GPA or its tryptic fragments, and by an ELISA assay [30].
• Mice were fed cCr or beta GPA and their muscles assayed for substrates and products of the CK reaction by 31P NMR spectroscopy and high performance liquid chromatography [31].

References