Pru J K, Austin K J, Haas A L, Hansen T R
Department of Animal Science, University of Wyoming, Laramie, Wyoming 82071, USA.
Biol Reprod. 2001 Nov;65(5):1471-80. doi: 10.1095/biolreprod65.5.1471.
The 1-8 family (1-8U, 1-8D, Leu-13/9-27) of interferon (IFN)-inducible genes encodes proteins that are components of multimeric complexes involved with transduction of antiproliferative and homotypic adhesion signals. Human 1-8 family members are highly similar and are regulated by type 1 and type 2 IFNs. Because the bovine uterus is bathed in conceptus-derived IFN tau during early pregnancy, it was hypothesized that members of the 1-8 family were upregulated in the bovine uterus during early pregnancy. Oligonucleotide primers were designed based on human and rat 1-8U and Leu-13 cDNAs and used in reverse transcription polymerase chain reactions to amplify bovine cDNAs from endometrial RNA. The bovine 1-8U cDNA was sequenced, found to be 84% identical to the human 1-8U, and used to screen a bovine endometrial cDNA library to isolate the full-length 1-8U and Leu-13 cDNAs. The inferred amino acid sequences of bovine 1-8U and Leu-13 were 72% and 73% identical to their respective human counterparts. Bovine 1-8U and Leu-13 retain an amino acid motif that is conserved in other 1-8 family members and in some ubiquitin-conjugating enzymes (E2s). This motif is critical for function of E2s in covalently linking ubiquitin to targeted proteins. Northern blotting revealed that bovine endometrial 1-8U and Leu-13 mRNAs were upregulated on Day 15 of pregnancy (P < 0.0001) and continued to accumulate through Day 18 of pregnancy (P < 0.05) when compared with endometrium from nonpregnant cows. The bovine 1-8U and Leu-13 mRNAs were also upregulated (P < 0.05) by IFN tau (25 nM) within 3 h, continued to accumulate through 12 h, and reached a plateau at 12-24 h in cultured bovine endometrial cells. In situ hybridization revealed that mRNAs encoding 1-8 family members were heavily localized to glandular epithelium but also were present to a lesser extent in the luminal epithelium and stroma. The temporal upregulation of 1-8U and Leu-13 mRNAs by pregnancy and IFN tau and tissue distribution of these mRNAs paralleled closely that of the ubiquitin homolog, IFN-stimulated gene product 17. These IFN-induced proteins probably work together to prepare the endometrium for adhesion of the developing conceptus.
干扰素（IFN）诱导基因的1-8家族（1-8U、1-8D、Leu-13/9-27）编码的蛋白质是多聚体复合物的组成成分，这些复合物参与抗增殖和同型黏附信号的转导。人类1-8家族成员高度相似，受1型和2型干扰素调控。由于在妊娠早期牛子宫浸泡在源自孕体的干扰素τ中，因此推测1-8家族成员在妊娠早期的牛子宫中表达上调。基于人类和大鼠的1-8U及Leu-13 cDNA设计寡核苷酸引物，并用于逆转录聚合酶链反应，以从子宫内膜RNA中扩增牛cDNA。对牛1-8U cDNA进行测序，发现其与人类1-8U的同源性为84%，并用于筛选牛子宫内膜cDNA文库，以分离全长1-8U和Leu-13 cDNA。牛1-8U和Leu-13的推导氨基酸序列与其各自人类对应物的同源性分别为72%和73%。牛1-8U和Leu-13保留了一个在其他1-8家族成员和一些泛素结合酶（E2s）中保守的氨基酸基序。该基序对于E2s将泛素共价连接到靶向蛋白质的功能至关重要。Northern印迹分析显示，与未怀孕母牛的子宫内膜相比，妊娠第15天时牛子宫内膜1-8U和Leu-13 mRNA表达上调（P<0.0001），并在妊娠第18天时持续积累（P<0.05）。在培养的牛子宫内膜细胞中，干扰素τ（25 nM）在3小时内也使牛1-8U和Leu-13 mRNA表达上调（P<0.05），持续积累至12小时，并在12 - 24小时达到平台期。原位杂交显示，编码1-8家族成员的mRNA主要定位于腺上皮，但在腔上皮和基质中也有少量存在。妊娠和干扰素τ对1-8U和Leu-13 mRNA的时间性上调以及这些mRNA的组织分布与泛素同源物、干扰素刺激基因产物17的情况密切平行。这些干扰素诱导的蛋白质可能共同作用，使子宫内膜为发育中的孕体着床做好准备。
