Wu Q, Maniatis T
Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
Cell. 1999 Jun 11;97(6):779-90. doi: 10.1016/s0092-8674(00)80789-8.
We have identified 52 novel human cadherin-like genes organized into three closely linked clusters. Comparison of the genomic DNA sequences with those of representative cDNAs reveals a striking genomic organization similar to that of immunoglobulin and T cell receptor gene clusters. The N-terminal extracellular and transmembrane domains of each cadherin protein are encoded by a distinct and unusually large exon. These exons are organized in a tandem array. By contrast, the C-terminal cytoplasmic domain of each protein is identical and is encoded by three small exons located downstream from the cluster of N-terminal exons. This unusual organization has interesting implications regarding the molecular code required to establish complex networks of neuronal connections in the brain and the mechanisms of cell-specific cadherin-like gene expression.
我们已经鉴定出52个新的类钙黏蛋白人类基因，它们组成了三个紧密相连的簇。将基因组DNA序列与代表性cDNA的序列进行比较，发现其基因组组织与免疫球蛋白和T细胞受体基因簇的基因组组织惊人地相似。每个钙黏蛋白的N端细胞外和跨膜结构域由一个独特且异常大的外显子编码。这些外显子以串联阵列的形式排列。相比之下，每个蛋白质的C端细胞质结构域是相同的，由位于N端外显子簇下游的三个小外显子编码。这种不同寻常的组织形式对于在大脑中建立复杂神经元连接网络所需的分子编码以及细胞特异性类钙黏蛋白基因表达的机制具有有趣的启示。
