Sd`a´抗原とその生合成酵素: 分化依存的な,そして発癌‐発生過程で制御される発現

書誌事項

タイトル別名
  • The Sda Antigen and Its Biosynthetic Enzyme: Differentiation-dependent and Onco-developmentally Regulated Expression.
  • Sda コウゲン ト ソノ セイゴウセイ コウソ ブンカ イゾンテキ ナ ソシ
  • Differentiation-dependent and Onco-developmentally Regulated Expression
  • 分化依存的な、そして発癌-発生過程で制御される発現

この論文をさがす

抄録

The blood group Sda antigen is a carbohydrate structure inherited as a dominant character and the β-linked N-acetylgalactosamine is the immunodominant sugar. This antigen is not confined to red cells but is mainly present in colon and kidney and is excreted in urine associated with the Tamm-Horsfall glycoprotein. A pentasaccharide fragment isolated from the Tamm-Horsfall glycoprotein with the GalNAcβ1, 4 (NeuAcα2, 3) Galβ1, 4GlcNAcβ1, 3Gal structure was found to have a very high Sda activity. The β1, 4-N-acetylgalactosaminyl-transferase involved in the biosynthesis of the Sda antigen (Sda-βGalNAc-transferase) strictly requires in acceptors a terminal galactose residue substituted at the O-3 position with N-acetylneuraminic acid. The tissue distribution of this enzyme correlates with the predominant localization of Sda antigen in kidney and colon. The Sda-βGalNAc-transferase is practically absent in neonatal guinea-pig kidney and in large intestine of suckling rat and is dramatically reduced in human colon carcinomas indicating that the expression is onco-developmentally regulated. In human colon carcinoma cells in culture only Caco-2 cells express the Sda-βGalNAc-transferase at a level that parallels the degree of enterocyte differentiation. A large amount of the enzyme is released in the soluble form by differentiated Caco-2 cells, preferentially from the basolateral face. One may postulate that a reduced susceptibility to infections caused by enterotoxigenic and pyelonephritogenic Escherichia coli strains which specifically bind to the NeuAcα2, 3Galβ-units has been the selective agent responsible for the dominant expression of the Sda-βGalNAc-transferase in distal kidney and colon.

収録刊行物

被引用文献 (1)*注記

もっと見る

参考文献 (102)*注記

もっと見る

詳細情報

問題の指摘

ページトップへ