van Engelen F A, de Jong A J, Meijer E A, Kuil C W, Meyboom J K, Dirkse W G, Booij H, Hartog M V, Vandekerckhove J, de Vries S C
Department of Molecular Biology, Agricultural University Wageningen, The Netherlands.
Plant Mol Biol. 1995 Mar;27(5):901-10. doi: 10.1007/BF00037018.
A 47 kDa glycoprotein, termed EP4, was purified from carrot cell suspension culture medium. An antiserum raised against EP4 also recognized a protein of 45 kDa that was ionically bound to the cell wall. EP4 was detected in culture media from both embryogenic and non-embryogenic cell lines and was found to be secreted by a specific subset of non-embryogenic cells. Secretion of the 47 kDa glycoprotein by embryogenic cells was not evident. The 45 kDa cell wall-bound EP4 protein was specific for non-embryogenic cells and was shown by immunolocalization to occur in the walls of clustered cells, with the highest levels in the walls separating adjacent cells. In seedlings, EP4 proteins were mainly found in roots. EP4 cDNA was cloned by screening a cDNA library with an oligonucleotide derived from an EP4 peptide sequence. The EP4 cDNA sequence was found to be 55% homologous to ENOD8, an early nodulin gene from alfalfa.
一种名为EP4的47 kDa糖蛋白从胡萝卜细胞悬浮培养基中纯化得到。针对EP4制备的抗血清还识别出一种与细胞壁离子结合的45 kDa蛋白质。在胚胎发生和非胚胎发生细胞系的培养基中均检测到EP4，并且发现它是由非胚胎发生细胞的一个特定亚群分泌的。胚胎发生细胞分泌47 kDa糖蛋白的情况不明显。45 kDa与细胞壁结合的EP4蛋白对非胚胎发生细胞具有特异性，免疫定位显示其存在于聚集细胞的细胞壁中，在分隔相邻细胞的细胞壁中含量最高。在幼苗中，EP4蛋白主要存在于根中。通过用源自EP4肽序列的寡核苷酸筛选cDNA文库克隆了EP4 cDNA。发现EP4 cDNA序列与来自苜蓿的早期结瘤素基因ENOD8有55%的同源性。
