Gomez-Escobar N, van den Biggelaar A, Maizels R
Institute of Cell, Animal and Population Biology, Ashworth Laboratories, University of Edinburgh, UK.
Gene. 1997 Oct 15;199(1-2):101-9. doi: 10.1016/s0378-1119(97)00353-3.
The full length cDNA sequence of a Type I transforming growth factor-beta (TGF-beta) receptor has been isolated from the filarial parasitic nematode Brugia pahangi. This new gene, designated Bp-trk-1, encodes a predicted 645 amino acid sequence with an N-terminal hydrophobic stretch which may act as a signal peptide. The extracellular portion (residues 15-187) is cysteine-rich and has three potential N-glycosylation sites. At positions 250-255 the protein contains the glycine-serine rich motif characteristic of Type I receptors. The closest homologue is a Caenorhabditis elegans gene (Q09488) in cosmid C32D5.2 which shares 67% amino acid identity with Bp-trk-1 in the most conserved kinase domain (aa 259-482). Other type I receptors such as C. elegans daf-1 and Drosophila tkv show 38-53% identity in the same region. Some residues conserved in Drosophila and vertebrates are not present in the B. pahangi sequence. RT-PCR amplification has been used to show that the transcript is expressed in the three main stages of the B. pahangi life cycle: microfilariae, infective larvae and adults. The ligand remains unknown at this time but is likely to be most similar to that for C. elegans Q09488.
从丝状寄生线虫彭亨布鲁线虫（Brugia pahangi）中分离出了I型转化生长因子-β（TGF-β）受体的全长cDNA序列。这个新基因被命名为Bp-trk-1，编码一个预测的645个氨基酸的序列，其N端有一段疏水序列，可能作为信号肽。细胞外部分（第15 - 187位氨基酸）富含半胱氨酸，有三个潜在的N-糖基化位点。在第250 - 255位氨基酸处，该蛋白含有I型受体特有的富含甘氨酸-丝氨酸的基序。最接近的同源物是秀丽隐杆线虫（Caenorhabditis elegans）粘粒C32D5.2中的一个基因（Q09488），在最保守的激酶结构域（第259 - 482位氨基酸）中与Bp-trk-1有67%的氨基酸同一性。其他I型受体，如秀丽隐杆线虫的daf-1和果蝇的tkv，在同一区域的同一性为38 - 53%。果蝇和脊椎动物中保守的一些残基在彭亨布鲁线虫序列中不存在。RT-PCR扩增已用于表明该转录本在彭亨布鲁线虫生命周期的三个主要阶段表达：微丝蚴、感染性幼虫和成虫。目前配体尚不清楚，但可能与秀丽隐杆线虫Q09488的配体最为相似。
