Apical Golgi localization of N,N′-diacetyllactosediamine synthase, β4GalNAc-T3, is responsible for LacdiNAc expression on gastric mucosa
Apical Golgi localization of N,N′-diacetyllactosediamine synthase, β4GalNAc-T3, is responsible for LacdiNAc expression on gastric mucosa
复制标题
DOI：
10.1093/glycob/cwl005
复制
发表时间：
2006-09-01
期刊：
影响因子：
4.3
通讯作者：
Narimatsu, Hisashi
中科院分区：
文献类型：
--
作者：
Ikehara, Yuzuru;Sato, Takashi;Narimatsu, Hisashi
最近克隆并鉴定的β 1，4-N-乙酰半乳聚糖酰基转移酶III（β 4GaINAc-T3）对具有β 1，4-键的GlcNAcP残基表现出GaINAc转移酶活性，形成N，N '-二乙酰乳糖二胺，GatNAc β 1，4GlcNAc（LacdiNAc或LDN）。虽然LacdiNAc在胃粘膜中尚未发现，但在我们以前的研究中检测到了大量的转录本。为了增加我们对β 4GaINAc-T3表达及其产物LacdiNAc的了解，我们使用新开发的抗体单克隆抗体（mAb）K1356检查了β 4GaINAc-T3在人胃粘膜中的精确定位。该抗体特异性地检测将β 4GaINAc-T3基因转染到MKN 45细胞中的酶，并且在细胞表面上产生的末端β GaINAc表位被凝集素--花紫藤凝集素（WFA）识别。β 4GaINAc-T3定位于胃粘膜表面粘液细胞的超微区，WFA阳性染色细胞分泌的粘蛋白。相比之下，在胃底腺的腺室细胞和幽门腺的少数细胞中，在细胞核的基底外侧位置观察到β 4GaINAc-T3，其中未检测到WFA反应性。抗Tn（GaINAc α-O-Ser/Thr）抗体染色与WFA染色不重叠。通过使用自动化正面亲和色谱（FAC）测量WFA的结合活性，我们发现WFA在所检查的糖链中结合最强的LacdiNAc。在肠化生细胞中既未检测到β 4GaINAc-T3阳性染色，也未检测到WFA阳性染色。这些结果表明，β 4GaINAc-T3的超微胞表达对于表面粘液细胞上LacdiNAc的形成是必需的，并且LacdiNAc和β 4GaINAc-T3是胃粘膜中表面粘液细胞的新的分化标志物。
beta 1,4-N-acetylgalactosan nyltransferase III (beta 4GaINAc-T3), which was recently cloned and identified, exhibits GaINAc transferase activity toward a GlcNAcP residue with beta 1,4-linkage, forming the N,N'-diacetyllactosediamine, GatNAc beta 1,4GIcNAc (LacdiNAc or LDN). Though LacdiNAc has not been found in the gastric mucosa, a large amount of transcript was detected in our previous study. To increase our knowledge of beta 4GaINAc-T3 expression and its product LacdiNAc, we examined the exact localization of beta 4GaINAc-T3 in human gastric mucosa using a newly developed antibody, monoclonal antibody (mAb) K1356. This antibody specifically detected the enzyme that transfected the beta 4GaINAc-T3 gene into MKN45 cells, and the terminal beta GaINAc epitope yielded on the cell surface was recognized by a lectin, Wisteria floribunda agglutinin (WFA). beta 4GaINAc-T3 was localized in the supra-miclear region of surface mucous cells in gastric mucosa, and WFA positively stained the mucins secreted by the cells. In contrast, in the cells of the glandular compartment in the fundic glands and a few cells in the pyloric glands, beta 4GaINAc-T3 was observed in the basolateral position of the nucleus, where no WFA reactivity was detected. The anti-Tn (GaINAc alpha-O-Ser/Thr) antibody staining did not overlap with the WFA staining. By measuring the binding activity of WFA using automated frontal affinity chromatography (FAC), we found WFA to bind most strongly LacdiNAc among the sugar chains examined. Neither beta 4GaINAc-T3 nor WFA-positive staining was detected in intestinal metaplastic cells. These results suggest that the supra-miclear expression of beta 4GaINAc-T3 is essential for the formation of LacdiNAc on the surface mucous cells and that LacdiNAc and beta 4GaINAc-T3 are novel differentiation markers of surface mucous cells in the gastric mucosa.