CLONING, EXPRESSION, AND CHROMOSOME MAPPING OF HUMAN GALECTIN-7
CLONING, EXPRESSION, AND CHROMOSOME MAPPING OF HUMAN GALECTIN-7
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DOI：
10.1074/jbc.270.11.5823
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发表时间：
1995-03-17
影响因子：
4.8
通讯作者：
CELIS, JE
中科院分区：
文献类型：
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作者：
MADSEN, P;RASMUSSEN, HH;CELIS, JE
半乳糖凝集素是一个β-半乳糖苷结合蛋白家族，参与调节细胞-细胞和细胞-基质的相互作用，本文报道了该家族一个新成员的克隆和表达（半乳糖凝集素-7），对应于IEF（等电聚焦）17（12，700 Da; pI，7.6），并且在SV 40转化的角质形成细胞（K14）中显著下调。使用从IEF 17肽序列反向翻译的简并寡脱氧核糖核苷酸，从λ gt 11 cDNA表达文库中克隆cDNA。通过瞬时转染的COS-1细胞表达的蛋白质的二维（二维凝胶电泳）分析确定，由半乳糖凝集素-7克隆编码的蛋白质与IEF 17共迁移，并结合乳糖酶。氨基酸序列与该家族其他成员的比对表明，对β-半乳糖苷相互作用起中心作用的氨基酸是保守的。半乳糖凝集素-7虽然没有典型的分泌信号肽，但被角质形成细胞部分地外化到培养基中。免疫印迹以及免疫荧光分析的人组织与一个特定的半乳糖凝集素-7抗体揭示了一个狭窄的分布的蛋白质，发现主要是在复层鳞状上皮。该抗原定位于基底角质形成细胞，尽管在基底上层中也发现了该抗原，尽管其水平较低，在基底上层中，该抗原集中于细胞与细胞接触的区域。其细胞定位以及其在K14角质形成细胞中的显著下调均暗示了正常生长控制所必需的细胞-细胞和/或细胞-基质相互作用中的作用。半乳糖凝集素-7基因定位于19号染色体。
The galectins are a family of beta-galactoside-binding proteins implicated in modulating cell-cell and cell-matrix interactions, Here we report the cloning and expression of a novel member of this family (galectin-7) that correspond to IEF (isoelectric focusing) 17 (12,700 Da; pI, 7.6) in the human keratinocyte protein data base, and that is strikingly down-regulated in SV40 transformed keratinocytes (K14). The cDNA was cloned from a lambda gt11 cDNA expression library using degenerated oligodeoxyribonucleotides back-translated from an IEF 17 peptide sequence. The protein encoded by the galectin-7 clone comigrated with IEF 17 as determined by two-dimensional (two-dimensional gel electrophoresis) analysis of proteins expressed by transiently transfected COS-1 cells, and bound lactase. Alignment of the amino acid sequences with other members of the family showed that the amino acids central to the beta-galactoside interaction are conserved. Galectin-7 was partially externalized to the medium by keratinocytes although it has no typical secretion signal peptide. Immunoblotting as well as immunofluorescence analysis of human tissues with a specific galectin-7 antibody revealed a narrow distribution of the protein which was found mainly in stratified squamous epithelium. The antigen localized to basal keratinocytes, although it was also found, albeit at lower levels, in the suprabasal layers where it concentrated to areas of cell to cell contact, Both, its cellular localization as well as its striking down-regulation in K14 keratinocytes imply a role in cell-cell and/or cell-matrix interactions necessary for normal growth control. The galectin-7 gene was mapped to chromosome 19.