Disease relevance of Bsg

• For the first time the MMP activation system EMMPRIN was shown to be relevant in cerebral ischemia [1].
• MS for 7 days beginning on postnatal day 14 induced a significant decrease in body weight and locomotion, while acupuncture treatment at acupoint Shenmen (HT7) resulted in a significant increase in both [2].

High impact information on Bsg

• Breaching the diffusion barrier that compartmentalizes the transmembrane glycoprotein CE9 to the posterior-tail plasma membrane domain of the rat spermatozoon [3].
• Although encoded by a single gene and mRNA in the rat, the majority of spermatozoal CE9 is of smaller apparent molecular mass than its hepatocytic counterpart due to the under-utilization of sites for asparagine-linked glycosylation [3].
• We have determined the sequence of CE9 and found it to be a Type Ia transmembrane protein identical to the MRC OX-47 T-cell activation antigen, a member of the immunoglobulin superfamily predicted to have two immunoglobulin-related loops and three asparagine-linked glycans disposed extracellularly [3].
• Originally identified as a basolateral domain-specific integral plasma membrane protein of the rat hepatocyte, CE9 mRNA and protein were also detected at high levels in the testis of the rat by Northern and Western blotting and immunoprecipitation [4].
• Amino-terminal amino acid microsequencing of CE9 immunoaffinity purified from epididymis suggested that the cleavage occurred on the carboxy-terminal side of arginine-74 in the primary sequence of CE9, resulting in the loss of approximately 40% of the amino acids in the extra-cellular domain of this transmembrane glycoprotein [4].

Biological context of Bsg

• Bsg expression profiles in the induced ovulation and CL regression models were similar to observations made in naturally cycling mature rats [5].
• The profile of Bsg expression during regression of the CL was examined using a model of induced luteolysis [5].
• Bsg expression persisted into pseudopregnancy (4-8 days post-hCG) and after functional luteal regression (12 days post-hCG) [5].
• Levels of Bsg mRNA were unchanged through follicular growth (0-48 h post-eCG) and increased during postovulatory luteinization (24 and 48 h post-hCG; P < 0.01) [5].
• In the cycling ovary, Bsg signaling localized to newly forming CL, the theca of preovulatory follicles, and appeared to be lower in CL from previous estrous cycles [5].

Anatomical context of Bsg

• A putative regulatory mechanism of Bsg expression was identified using an in vitro model; treatment of cultured granulosa cells with hCG significantly augmented Bsg mRNA expression levels [5].
• 5A11/Basigin-2 expression was limited to the retina, specifically to photoreceptor cells, where it appeared to be most concentrated in the inner segments [6].
• The MRC OX-47 monoclonal antibody recognizes a membrane antigen present at low levels on many lymphocytes but whose expression is markedly increased on activation with mitogens. cDNA clones for the OX-47 antigen were isolated from an expression library and the protein sequence deduced [7].
• In addition to lymphoblasts the OX-47 antigen was localized on a variety of other cell types including various immature cells, endothelia and cells with excitable membranes [7].
• A sequence of 37 amino acids that included all the transmembrane region was identical to that of the chicken HT7 antigen present on endothelium in brain and erythroblasts [7].

Associations of Bsg with chemical compounds

• CE9 is a posterior-tail domain-specific integral plasma membrane glycoprotein of the rat testicular spermatozoon [3].
• Basigin mRNA was localized strongly in the luminal epithelium on day 1 of pregnancy and gradually decreased to a basal concentration from day 3 to day 5 of pregnancy [8].
• When assessed by labeling semithin frozen sections of liver tissue with a fluorescent lectin specific for alpha 2,6-linked sialic acid, the reduced sialylation observed for CE9 was found to extend to other hepatocytic glycoconjugates in the livers of peroxisome proliferator-treated rats [9].
• The metabolic activation of hepatocytes that occurs upon administration of thyroid hormone to euthyroid rats was found to be accompanied by 2.2 +/- 0.3-fold and 1.9 +/- 0.3-fold increases in the levels of CE9 mRNA and protein respectively [10].
• Following 72 h of ethanol withdrawal, acupuncture was applied at bilateral Shenmen (HT7) points for 1 min [11].

Other interactions of Bsg

• Matrix metalloproteinase induction by EMMPRIN in experimental focal cerebral ischemia [1].
• RT-PCR showed a concomitant increase in the mRNA expression of membrane type-1 MMP (MT1-MMP) and extracellular MMP inducer (EMMPRIN) [12].

Analytical, diagnostic and therapeutic context of Bsg

• Extracellular EMMPRIN was measured by Western blot of the ischemic and nonischemic basal ganglia and cortex separately [1].
• Immunohistochemistry was used to localize EMMPRIN on cerebral microvessels [1].
• In this study we describe changes of the MMP inducer protein (EMMPRIN) following experimental cerebral ischemia (induced for 3 h and followed by 24 h reperfusion, suture model) in rats [1].
• Immunogold electron microscopy was used to pinpoint the positions of the boundaries of these CE9-containing plasma membrane domains at a high level of resolution [13].
• Western blotting, immunofluorescence and immunogold electron microscopy were used to examine the compartmentalization, processing and redistribution of the integral plasma membrane protein CE9 on the spermatozoa of rats, mice and hamsters [13].

References