Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P02749 (beta2-glycoprotein I)
 836 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Outer renal medulla calmodulin-binding proteins from a soluble protein fraction and a plasma membrane fraction solubilized in CHAPS were retained on a calmodulin-Sepharose 4B column in the presence of Ca2+, and subsequently eluted by EGTA. The calmodulin-binding proteins constituted 2.5% of the soluble protein and 0.1% of the solubilized membrane protein. beta2-glycoprotein I was identified as a calmodulin-binding protein both by N-terminal sequencing and by immunoblotting. Quantification showed that beta2-glycoprotein I constituted the major part (approx. 35%) of the calmodulin-binding membrane proteins, but only a minor part (approx. 0.1%) of the calmodulin-binding proteins in the soluble fraction. These results show for the first time that beta2-glycoprotein I binds calmodulin and that beta2-glycoprotein I may in kidney be a membrane-associated protein. Immunohistochemical studies identified beta2-glycoprotein I in several parts of the cortex and the medulla of the kidney, including Bowman's capsula, the tubular lumen and the tubular epithelium, indicating that beta2-glycoprotein I, despite its relatively high molecular mass, is filtrated in the glomerulus and subsequently reabsorbed by the tubular epithelium. This is in agreement with beta2-glycoprotein I being a marker for renal tubular disease.
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PMID:Identification of beta2-glycoprotein I as a membrane-associated protein in kidney: purification by calmodulin affinity chromatography. 918 40

Since several forms of autoimmunity have been associated with urticaria, we performed a detailed survey of autoantibodies in patients with idiopathic subacute and chronic urticaria. Sera from 25 consecutive patients referred for evaluation of urticaria were tested for the presence of autoantibodies and compared to sera from seventy-five control samples examined from individuals being treated for other allergic diseases. Study patients ranged in age from 15 to 73 years, with a mean of 48. One patient had a diagnosis of inflammatory bowel disease and one had multiple myeloma, but otherwise there were no other diagnoses of disease specifically involving immunity other than atopy. No study patients had a concurrent diagnosis of autoimmune thyroid disease. The test sera were examined for autoantibodies and for antibodies to H. pylori. Antibodies to thyroid peroxidase (TPO) were found significantly (p < 0.01) more common in urticaria (20%] than in controls (0%). Rheumatoid factor(RF) was also found in significantly (p < 0.05) increased in urticaria (16%) compared to controls [0%). Neither H. pylori antibody nor other autoantibodies were present in significant numbers of urticaria patients when compared to controls. Tested autoantibodies included those to thyroglobulin, sDNA, SSA/SSB, ENA, cardiolipin, beta2-glycoprotein I, myeloperoxidase, proteinase-3, smooth muscle, ANA, human lysosomal-associated membrane protein, and bactericidal permeability increasing protein. Thus, patients with urticaria were somewhat more likely to have a thyroid autoantibody to TPO or to have RF. This survey demonstrates that while some markers of autoimmunity may be increased in urticaria patients, broad nonspecific autoimmunity is not found.
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PMID:Are autoantibodies present in patients with subacute and chronic urticaria? 1143 65

Erythrocyte clearance is reviewed in the context of what is known in 2003 on clearance of apoptotic cells in vitro and in vivo. Thus, emphasis is put on the role of the innate immune system comprised of naturally occurring autoantibodies (NAbs) and complement. Oxidative damage, cellular senescence and diffusion-controlled exoplasmic cross-linking appear to generate oligomers of band 3 (anion transport protein) that are a prerequisite for anti-band 3 NAb binding to human red blood cells (RBC). Similar processes seem to be responsible for premature RBC clearance in hemoglobinopathies and membrane protein deficiencies. The review discusses why NAb binding alone is insufficient and how bound NAbs may enhance complement deposition. Clearance of RBC is not only the result of cell-bound opsonins, but is enhanced by the loss of RBC membrane constituents, such as CD47 and sialic acids. As long as these constituents are present on RBC in normal numbers and topologic arrangement, they bind to their respective receptors on macrophages, elicit a negative signal that appears to prevent the macrophage from engulfing bound RBC. Exposure of phosphatidylserine is not a primary signal for RBC removal and where exposed it initiates binding of CRP or of beta-2-glycoprotein I and NAbs.
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PMID:Innate immune and non-immune mediators of erythrocyte clearance. 1509 82

The first, obligatory replication phase of malaria parasite infections is characterized by rapid expansion and differentiation of single parasites in liver cells, resulting in the formation and release of thousands of invasive merozoites into the bloodstream. Hepatic Plasmodium development occurs inside a specialized membranous compartment termed the parasitophorous vacuole (PV). Here, we show that, during the parasite's hepatic replication, the C-terminal region of the parasitic PV membrane protein exported protein 1 (EXP-1) binds to host Apolipoprotein H (ApoH) and that this molecular interaction plays a pivotal role for successful Plasmodium liver-stage development. Expression of a truncated EXP-1 protein, missing the specific ApoH interaction site, or down-regulation of ApoH expression in either hepatic cells or mouse livers by RNA interference resulted in impaired intrahepatic development. Furthermore, infection of mice with sporozoites expressing a truncated version of EXP-1 resulted in both a significant reduction of liver burden and delayed blood-stage patency, leading to a disease outcome different from that generally induced by infection with wild-type parasites. This study identifies a host-parasite protein interaction during the hepatic stage of infection by Plasmodium parasites. The identification of such vital interactions may hold potential toward the development of novel malaria prevention strategies.
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PMID:Plasmodium berghei EXP-1 interacts with host Apolipoprotein H during Plasmodium liver-stage development. 2813 45