Molecular cloning of a novel human CC chemokine liver and activation-regulated chemokine (LARC) expressed in liver - Chemotactic activity for lymphocytes and gene localization on chromosome
Molecular cloning of a novel human CC chemokine liver and activation-regulated chemokine (LARC) expressed in liver - Chemotactic activity for lymphocytes and gene localization on chromosome
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DOI：
10.1074/jbc.272.9.5846
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发表时间：
1997-02-28
影响因子：
4.8
通讯作者：
Nomiyama, H
中科院分区：
文献类型：
--
作者：
Hieshima, K;Imai, T;Nomiyama, H
从GenBank表达序列标签数据库中鉴定出可能编码一种新的人CC趋化因子的部分重叠cDNA序列。使用这些序列，我们分离出全长cDNA编码的蛋白质的96个氨基酸残基与其他CC趋化因子的20-28%的同一性。经北方杂交证实，该趋化因子主要表达于肝组织，并能被佛波醇肉豆蔻酸酯诱导表达。因此，我们将这种趋化因子命名为来自肝脏的LARC和活化调节趋化因子。我们定位LARC基因接近染色体标记D2 S159在染色体2 q33-q37的体细胞和辐射杂交定位，并分离出两个酵母人工染色体克隆含有LARC基因从这个区域。为了制备LARC，我们将cDNA亚克隆到杆状病毒载体中并在昆虫细胞中表达。分泌的蛋白质起始于Ala-27，并且对淋巴细胞具有显著的趋化性。在1 μ g/ml的浓度下，它还显示出对粒细胞的弱趋化活性。然而，与其他CC趋化因子不同，LARC对单核细胞THP-1细胞或血液单核细胞没有趋化性。用分泌的碱性磷酸酶-（His）标记的LARC（6）特异性结合淋巴细胞，该结合仅被LARC竞争，而不被其他CC或CXC趋化因子竞争。Scatchard分析揭示了淋巴细胞上LARC的单一类别的受体，其Kd为0.4 nM和2100个位点/细胞。LARC是一种新的CC趋化因子，可能代表了一组新的位于2号染色体上的CC趋化因子。
Partial overlapping cDNA sequences likely to encode a novel human CC chemokine were identified from the GenBank Expressed Sequence Tag data base. Using these sequences, we isolated full-length cDNA encoding a protein of 96 amino acid residues with 20-28% identity to other CC chemokines. By Northern blot, this chemokine was mainly expressed in liver among various tissues and strongly induced in several human cell Lines by phorbol myristate acetate. We thus designated this chemokine as LARC from Liver and Activation-Regulated Chemokine. We mapped the LARC gene close to the chromosomal marker D2S159 at chromosome 2q33-q37 by somatic cell and radiation hybrid mappings and isolated two yeast artificial chromosome clones containing the LARC gene from this region. To prepare LARC, we subcloned the cDNA into a baculovirus vector and expressed it in insect cells. The secreted protein started at Ala-27 and was significantly chemotactic for lymphocytes. At a concentration of 1 mu g/ml, it also showed a weak chemotactic activity for granulocytes. Unlike other CC chemokines, however, LARC was not chemotactic for monocytic THP-I cells or blood monocytes. LARC tagged with secreted alkaline phosphatase-(His)(6) bound specifically to lymphocytes, the binding being competed only by LARC and not by other CC or CXC chemokines. Scatchard analysis revealed a single class of receptors for LARC on lymphocytes with a K-d of 0.4 nM and 2100 sites/cell. Collectively, LARC is a novel CC chemokine, which may represent a new group of CC chemokines localized on chromosome 2.