Roberts R M, Klemann S W, Leaman D W, Bixby J A, Cross J C, Farin C E, Imakawa K, Hansen T R
Department of Animal Sciences, University of Missouri, Columbia 65211.
J Reprod Fertil Suppl. 1991;43:3-12.
Ovine and bovine trophoblast protein-1 (oTP-1 and bTP-1) have been strongly implicated as antiluteolytic agents and responsible for maternal recognition of pregnancy in sheep and cattle, respectively. Both are interferons (IFN) belonging to the IFN-alpha family, but their length (172 residues versus 166 for most IFN-alpha) places them in an unusual subclass (the IFN-alpha II). The various isoforms of oTP-1 and bTP-1 produced by trophoblast tissue appear to arise in part from translation of multiple mRNAs which are themselves the products of distinct genes. These genes, like those for other IFN-alpha, are without introns. However, the genes for oTP-1 and bTP-1 form a distinct subgroup within the IFN-alpha II on the basis of their overall primary sequences and the high conservation of the 3'-untranslated ends of their transcription units. The bTP-1 genes also differ from the bovine IFN-alpha II in the organization of the promoter regions upstream from the transcription start site. Nevertheless, computer-aided analysis of the primary polypeptide sequences of oTP-1 and bTP-1 indicates that the molecules are likely to have approximately the same shapes and dimensions as all other IFN-alpha molecules. It remains to be determined whether they have unique biological properties which distinguish them from other IFN-alpha molecules.
绵羊和牛的滋养层蛋白-1（oTP-1和bTP-1）分别被强烈认为是抗黄体溶解因子，并且分别在绵羊和牛中负责母体对妊娠的识别。它们都是属于IFN-α家族的干扰素，但它们的长度（172个残基，而大多数IFN-α为166个残基）使它们属于一个不同寻常的亚类（IFN-α II）。滋养层组织产生的oTP-1和bTP-1的各种同工型似乎部分源自多个mRNA的翻译，而这些mRNA本身是不同基因的产物。这些基因与其他IFN-α的基因一样，没有内含子。然而，基于其总体一级序列以及转录单位3'-非翻译末端的高度保守性，oTP-1和bTP-1的基因在IFN-α II中形成了一个独特的亚组。bTP-1基因在转录起始位点上游的启动子区域的组织上也与牛IFN-α II不同。尽管如此，对oTP-1和bTP-1的一级多肽序列进行计算机辅助分析表明，这些分子可能具有与所有其他IFN-α分子大致相同的形状和尺寸。它们是否具有使其与其他IFN-α分子区分开来的独特生物学特性还有待确定。
