Yanase Hiroshi, Sugino Hidehiko, Yagi Takeshi
KOKORO Biology Group, Laboratories for Integrated Biology, Graduate School of Frontier Biosciences, Osaka University, Yamadoka, Suita, Japan.
Genomics. 2004 Apr;83(4):717-26. doi: 10.1016/j.ygeno.2003.09.022.
CNR/Pcdhalpha family proteins are known as synaptic cadherins and Reelin receptors. Here we report the complete genomic sequence and organization of the rat CNR. The rat CNR cluster encodes 15 variable and 3 constant exons. The genomic organizations of the rat, mouse, and human CNR/Pcdhalpha are orthologous. The percentage identity of the coding regions between the rat and the mouse is 93.6% on average at the nucleic acid level, and between rat and human it is 82.8%. The rat CNRs (v1-v13) also contain an RGD motif in the extracellular cadherin 1 domains and cysteine repeats that are characteristic of the transmembrane and cytoplasmic domains of CNR proteins. The number of variable exons in the rat CNR cluster is identical to that of the human. The rat CNR cluster has one more variable exon than is found in laboratory mouse strains, because in the mouse a variable exon located between v7 and v8 is divided by the insertion of a retrotransposon. This exon is not disrupted in the rat, in which it is transcribed. By in silico analysis, CNR/Pcdhalpha was also mapped to rat chromosome 18, but the orientation was opposite for the mouse CNR/Pcdhalpha gene cluster. The relative expression profiles of the rat CNRs (v1-v13) show that all the CNRs are transcribed, but there are variations in the expression ratios among the CNRs.
CNR/Pcdhalpha家族蛋白被认为是突触钙黏蛋白和Reelin受体。在此我们报告大鼠CNR的完整基因组序列和结构。大鼠CNR基因簇编码15个可变外显子和3个恒定外显子。大鼠、小鼠和人类的CNR/Pcdhalpha的基因组结构是直系同源的。大鼠和小鼠之间编码区在核酸水平上的平均百分比同一性为93.6%，大鼠和人类之间为82.8%。大鼠的CNR（v1 - v13）在细胞外钙黏蛋白1结构域中还含有一个RGD基序以及CNR蛋白跨膜和胞质结构域特有的半胱氨酸重复序列。大鼠CNR基因簇中可变外显子的数量与人类的相同。大鼠CNR基因簇比实验室小鼠品系中的多一个可变外显子，因为在小鼠中位于v7和v8之间的一个可变外显子被反转录转座子的插入所分割。这个外显子在大鼠中未被破坏且在大鼠中被转录。通过电子分析，CNR/Pcdhalpha也被定位到大鼠18号染色体上，但与小鼠CNR/Pcdhalpha基因簇的方向相反。大鼠CNR（v1 - v13）的相对表达谱表明所有的CNR都被转录，但各CNR之间的表达比例存在差异。
