Pregnancy and interferon-tau upregulate gene expression of members of the 1-8 family in the bovine uterus.
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.
Pru
J K
JK
Department of Animal Science, University of Wyoming, Laramie, Wyoming 82071, USA.
Austin
K J
KJ
Haas
A L
AL
Hansen
T R
TR
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002417:Cattle / Q000235:genetics*; D018076:DNA, Complementary / Q000737:chemistry; D005260:Female; D005786:Gene Expression Regulation; D017403:In Situ Hybridization; D007370:Interferon Type I / Q000494:pharmacology*; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000494:pharmacology*; D012333:RNA, Messenger / Q000032:analysis; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014599:Uterus / Q000378:metabolism*
D018076:DNA, Complementary; C080082:IFITM3 protein, human; D007370:Interferon Type I; D008565:Membrane Proteins; D011257:Pregnancy Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C020947:interferon tau