Novel Full-length Cdnas Differentially Expressed During

我们克隆了一个新的造血粒细胞集落刺激因子（G-CSF）诱导的嗅调节素相关糖蛋白，称为hGC-1（人G-CSF刺激克隆-1）。mRNA差异显示结合改良的两相液体培养系统使用。培养物中富集了红细胞、骨髓和巨核细胞谱系的早期前体，这些谱系分别在用红细胞生成素、G-CSF和血小板生成素诱导后分离。对来自富集细胞的RNA进行差异显示分析以鉴定谱系特异性表达的基因。对G-CSF特异性诱导的一个克隆hGC-1进行了表征。hGC-1 cDNA全长2861 bp，包含一个1530个核苷酸的开放阅读框，编码510个氨基酸，含有一个信号肽和6个N-糖基化基序。hGC-1的蛋白质序列显示其是嗅觉调节蛋白家族的糖蛋白，该家族包括嗅觉调节蛋白、TIGR、Noelin-2和latrophilin-1。嗅觉调节素样基因表现出特征性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不同。hGC-1在前列腺、小肠和结肠中强烈表达，在骨髓和胃中中度表达，在其他组织中检测不到。体外翻译和离体表达表明hGC-1是一个N-连接糖蛋白。hGC-1基因定位于染色体13q14.3。总之，我们的研究结果表明，hGC-1主要表达为细胞外嗅调节素相关的糖蛋白在正常的骨髓特异性谱系分化，这表明一个基质相关的功能的hGC-1在分化的可能性。

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.