Ellinwood N M, McCue J M, Gordy P W, Bowen R A
Department of Physiology, Colorado State University, Fort Collins 80523, USA.
J Interferon Cytokine Res. 1998 Sep;18(9):745-55. doi: 10.1089/jir.1998.18.745.
Mx proteins are GTPases that are stringently induced in cells from many vertebrates on exposure to type I interferons (IFNs), and expression of some Mx proteins potently inhibits replication of specific viruses. Two cDNAs encoding bovine Mx proteins were isolated from an endometrial phage library. The open reading frames (ORFs) of these two clones predict proteins of 654 (Mxl) and 648 (Mxl-a) residues. Both possess the tripartite GTPase domains, dynamin signature, and leucine zipper motifs conserved in all other Mx proteins identified. The bovine protein sequences show highest identity to ovine Mx (93%) and are substantially similar to human MxA (73%) and mouse Mx1 (63%). Based on differences between the two bovine clones in the coding and 3'-untranslated regions, it was concluded that they represent two alleles of one gene, and heterozygous and homozygous cattle were identified. Expression of Mx mRNA was rapidly induced in cultured bovine cells by treatment with IFN.
Mx蛋白是一种GTP酶，在许多脊椎动物的细胞中，当暴露于I型干扰素（IFN）时会被严格诱导，并且一些Mx蛋白的表达能有效抑制特定病毒的复制。从子宫内膜噬菌体文库中分离出两个编码牛Mx蛋白的cDNA。这两个克隆的开放阅读框（ORF）预测的蛋白质分别有654个（Mxl）和648个（Mxl-a）残基。两者都具有三方GTP酶结构域、发动蛋白特征以及在所有其他已鉴定的Mx蛋白中保守的亮氨酸拉链基序。牛的蛋白质序列与绵羊Mx的一致性最高（93%），并且与人类MxA（73%）和小鼠Mx1（63%）有很大的相似性。基于两个牛克隆在编码区和3'非翻译区的差异，得出它们代表一个基因的两个等位基因的结论，并且鉴定出了杂合和纯合的牛。用IFN处理培养的牛细胞后，Mx mRNA的表达迅速被诱导。
