Kelly L E, Phillips A M, Delbridge M, Stewart R
Department of Genetics, University of Melbourne, Parkville, Victoria, Australia.
Insect Biochem Mol Biol. 1997 Aug-Sep;27(8-9):783-92. doi: 10.1016/s0965-1748(97)00062-3.
Using antibodies raised against the Drosophila Ca(2+)-binding protein DCABP-23, we have isolated two distinct cDNA clones that encode Ca(2+)-binding proteins of the invertebrate sarcoplasmic calcium-binding protein (SCP) family. Southern blot analysis of whole genomic DNA has shown that one of the clones, Dcabp-A.1, is present in more than one copy in the genome of the fly, and is located in the beta-heterochromatic region at cytological division 80 on chromosome III. The expression pattern of this transcript shows that it is present in the tubular but not the fibrillar muscles of the adult thorax. This expression pattern is consistent with this being a true SCP. In contrast, the expression pattern of the transcript corresponding to the second cDNA clone is exclusive to neural tissue. This transcript derives from a single copy gene, and is located at cytological position 89 D on chromosome III. Comparative analysis of the amino acid sequences from the proteins encoded by the two cDNAs with that of the original DCABP-23 protein indicates that the purified DCABP-23 contained mainly the DCABP-A.1 protein. The identification of members of the SCP family of proteins in Drosophila, will allow for a future genetic investigation of the function of these ubiquitous proteins.
利用针对果蝇钙结合蛋白DCABP - 23产生的抗体，我们分离出了两个不同的cDNA克隆，它们编码无脊椎动物肌浆钙结合蛋白（SCP）家族的钙结合蛋白。对全基因组DNA的Southern印迹分析表明，其中一个克隆Dcabp - A.1在果蝇基因组中以多个拷贝存在，位于第三条染色体细胞分裂80处的β异染色质区域。该转录本的表达模式表明它存在于成年胸部的管状肌而非纤维状肌中。这种表达模式与它是一种真正的SCP一致。相比之下，对应于第二个cDNA克隆的转录本的表达模式仅存在于神经组织中。该转录本来自一个单拷贝基因，位于第三条染色体的89D细胞位置。对这两个cDNA编码的蛋白质的氨基酸序列与原始DCABP - 23蛋白的氨基酸序列进行比较分析表明，纯化的DCABP - 23主要包含DCABP - A.1蛋白。在果蝇中鉴定SCP家族蛋白质成员，将有助于未来对这些普遍存在的蛋白质的功能进行遗传学研究。
