Novel Full-length Cdnas Differentially Expressed During

我们克隆了一种新的造血粒细胞集落刺激因子(G-CSF)诱导的嗅球蛋白相关糖蛋白，命名为HGC-1(人G-CSF刺激的克隆-1)。结合改良的两相液体培养系统，采用mRNA差异显示技术。分别用促红细胞生成素、粒细胞集落刺激因子和血小板生成素诱导分离红系、髓系和巨核系的早期前体细胞。从浓缩的细胞中提取的RNA进行差异显示分析，以确定谱系特异性表达基因。对G-CSF特异性诱导的克隆HGC-1进行了鉴定。HGC-1的2861个碱基对的克隆包含一个1530个核苷酸的开放阅读框，翻译成一个510个氨基酸的蛋白质，带有一个信号肽和6个N-连接的糖基化基序。HGC-1的蛋白质序列分析表明，HGC-1是一种分子内酯家族的糖蛋白，包括分子内酯、TIGR、Noelin-2和LatroPhilin-1。类嗅觉蛋白基因表现出特有的组织限制性表达模式；表达这些基因的特定组织在家族成员中有所不同。HGC-1在前列腺、小肠和结肠中强表达，在骨髓和胃中中等表达，在其他组织中检测不到。体外翻译和体外表达表明，HGC-1是一种N-连接的糖蛋白。HGC-1基因定位于染色体13q14.3。综上所述，我们的研究结果表明，在正常的髓系分化过程中，HGC-1主要作为一种细胞外分子相关的糖蛋白表达，提示HGC-1在分化过程中可能具有与基质相关的功能。

We have cloned a novel hematopoietic granulocyte colony-stimulating factor (G-CSF)-induced olfactomedin-related glycoprotein, termed hGC-1 (human G-CSF-stimulated clone-1). mRNA differential display was used in conjunction with a modified two-phase liquid culture system. Cultures were enriched for early precursors of erythroid, myeloid, and megakaryocytic lineages, which were isolated after induction with erythropoietin, G-CSF, and thrombopoietin, respectively. RNA from the enriched cells was subjected to differential display analysis to identify lineage-specific expressed genes. One clone specifically induced by G-CSF, hGC-1, was characterized. The 2861-base-pair cDNA clone of hGC-1 contained an open reading frame of 1530 nucleotides, translating into a protein of 510 amino acids with a signal peptide and six N-linked glycosylation motifs. The protein sequence of hGC-1 showed it to be a glycoprotein of the olfactomedin family, which includes olfactomedin, TIGR, Noelin-2 and latrophilin-1. Olfactomedin-like genes show characteristic tissue-restricted patterns of expression; the specific tissues expressing these genes differ among the family members. hGC-1 was strongly expressed in the prostate, small intestine, and colon, moderately expressed in the bone marrow and stomach, and not detectable in other tissues. In vitro translation and ex vivo expression showed hGC-1 to be an N-linked glycoprotein. The hGC-1 gene locus mapped to chromosome 13q14.3. Together, our findings indicate that hGC-1 is primarily expressed as an extracellular olfactomedin-related glycoprotein during normal myeloid-specific lineage differentiation, suggesting the possibility of a matrix-related function for hGC-1 in differentiation.