Suzuki Takako, Matsubara Yutaka, Kitani Hiroshi, Ikeda Hidetoshi
Department of Immunology, National Institute of Animal Health, 3-1-5, Kannondai, Tsukuba, Ibaraki 305-0856, Japan.
Department of Planning and Coordination, National Institute of Animal Health, 3-1-5, Kannondai, Tsukuba, Ibaraki 305-0856, Japan.
J Gen Virol. 2003 May;84(Pt 5):1309-1316. doi: 10.1099/vir.0.18763-0.
A candidate gene of the bovine leukaemia virus (BLV) receptor (BLVR) was cloned previously and predicted to encode a transmembrane protein. Subsequent cloning of related genes from other organisms indicated that the candidate gene is related, but unique, to a gene family of the delta subunit of the adaptor protein (AP) complex 3, AP-3. Therefore, bovine cDNAs (boAP3delta) that are highly homologous to the candidate gene were cloned and sequenced. The nucleotide sequences suggested that the boAP3delta cDNA encodes the delta subunit of boAP3 without transmembrane domains. Part of the AP3delta cDNA isolated from the lymph node, spleen and MDBK cells, from which the BLVR candidate cDNA was derived, has almost the same nucleotide sequences as the boAP3delta cDNA. A boAP3delta protein tagged with green fluorescent protein was localized in the cytoplasm and incorporated into AP-3 in bovine cells. Unlike the previous report about the candidate gene, the boAP3delta gene introduced into murine NIH 3T3 cells did not increase the susceptibility of the cells to BLV infection. Many small insertions and deletions of nucleotides could generate the predicted transmembrane and cytoplasmic regions of the BLVR protein from the prototypic boAP3delta gene.
先前已克隆出牛白血病病毒（BLV）受体（BLVR）的一个候选基因，并预测其编码一种跨膜蛋白。随后从其他生物体中克隆相关基因表明，该候选基因与衔接蛋白（AP）复合物3（AP - 3）的δ亚基基因家族相关，但具有独特性。因此，克隆并测序了与该候选基因高度同源的牛cDNA（boAP3δ）。核苷酸序列表明，boAP3δ cDNA编码无跨膜结构域的boAP3δ亚基。从先前分离出BLVR候选cDNA的淋巴结、脾脏和MDBK细胞中分离出的部分AP3δ cDNA，其核苷酸序列与boAP3δ cDNA几乎相同。用绿色荧光蛋白标记的boAP3δ蛋白定位于细胞质中，并在牛细胞中整合到AP - 3中。与先前关于候选基因的报道不同，导入小鼠NIH 3T3细胞的boAP3δ基因并未增加细胞对BLV感染的易感性。许多核苷酸的小插入和缺失可从原型boAP3δ基因产生预测的BLVR蛋白跨膜和细胞质区域。
