Expression of β-N-Acetylgalactosaminylated N-Linked Sugar Chains Is Associated with Functional Differentiation of Bovine Mammary Gland
Expression of β-N-Acetylgalactosaminylated N-Linked Sugar Chains Is Associated with Functional Differentiation of Bovine Mammary Gland
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β-N-乙酰半乳糖胺化N联糖链的表达与牛乳腺的功能分化相关
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
K. Furukawa
中科院分区：
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作者：
Takeshi Sato;J. Taka;N. Aoki;T. Matsuda;K. Furukawa
在哺乳期，乳腺合成大量的糖蛋白，包括那些组成乳脂球膜（MFGM）的糖蛋白。我们先前的研究表明，具有GalNAc β 1->4GlcNAc结构的N-连接糖链似乎在泌乳早期在牛MFGM糖蛋白中增加[Ujita等人（1993）FEBS Lett. 332，119-122]。使用花旗参凝集素（WFA）和蓖麻凝集素-I（RCA-I）对泌乳和泌乳后牛乳腺的膜糖蛋白进行Western印迹分析，花旗参凝集素（WFA）结合以β-N-乙酰半乳糖胺终止的寡糖，蓖麻凝集素-I（RCA-I）优先结合以β-1，4-半乳糖终止的寡糖，结果表明，在泌乳后的乳腺样品中，蛋白条带的数量和对WFA的反应性显著降低，但对RCA-1的反应性不显著降低。从泌乳牛乳腺中建立原代培养的上皮细胞，并在存在催乳激素混合物的情况下在胶原包被的培养皿上进行培养，结果表明，具有GalNAc β 1->4GlcNAc结构的N-连接糖链在功能分化的细胞中表达，而不改变寡糖的表观β-半乳糖基化。这些结果有力地表明，N-连接糖链上GalNAc β 1->4GlcNAc结构的表达与乳腺分化有关。
: During lactation the mammary gland synthesizes a large amount of glycoproteins including those composing milk fat globule membrane (MFGM). Our previous study showed that N-linked sugar chains with GalNAc beta1-->4GlcNAc structure appears to increase in bovine MFGM glycoproteins during early lactation [Ujita et al. (1993) FEBS Lett. 332, 119-122]. Western blot analysis of membrane glycoproteins from lactating and post-lactating bovine mammary glands using Wistaria floribunda agglutinin (WFA), which binds oligosaccharides terminating with beta-N-acetylgalactosamine, and Ricinus communis agglutinin-I (RCA-I), which binds oligosaccharides preferentially terminating with beta-1,4-galactose, showed that the number and reactivity of protein bands to WFA but not to RCA-I decrease drastically in the post-lactating mammary sample. Establishment of primary cultured epithelial cells from lactating bovine mammary gland and their culture on collagen-coated dishes in the presence of a mixture of lactogenic hormones revealed that N-linked sugar chains with GalNAc beta1-->4GlcNAc structure are expressed in the functionally differentiated cells without altering the apparent beta-galactosylation of the oligosaccharides. These results strongly suggest that the expression of GalNAc beta1-->4GlcNAc structure on N-linked sugar chains is associated with the mammary gland differentiation.