Synthesis and processing of ovine trophoblast protein-1 and bovine trophoblast protein-1, conceptus secretory proteins involved in the maternal recognition of pregnancy | Academic Article individual record

Ovine and bovine trophoblast protein-1 (oTP-1 and bTP-1) are newly discovered proteins produced by embryonic tissues for a limited period in early gestation. They appear to act as agents that prevent regression of the corpus luteum during early pregnancy in the ewe and cow. Ovine TP-1 [mol wt (Mr), 17,000] consists of three or four isoelectric variants (pi 5.4â€5.7), whereas bTP-1, which cross-reacts with antiserum to oTP-1, is found as two predominant Mr classes (Mr, 22,000 and 24,000), each with several isoelectric variants (in the pi range 6.3â€6.8). Cell-free translation of ovine conceptus mRNA yields pre-oTP-1 of 21,000 Mr which is processed to a 17,000 Mr form in the presence of canine pancreatic microsomes. However, preoTP- 1 also consists of three or four isoelectric variants, assumed to have arisen by translation of multiple mRNA species. Ovine TP-1 is not glycosylated. When bovine conceptus mRNA is translated, a group of four or five isoforms of pre-bTP-1 are generated, each with a Mr of 19,000. In the presence of microsomes the Mr shifts upward to about 21,500. Bovine conceptuses cultured in presence of either [ 3 H]glucosamine or [ 3 H]mannose incorporate label into both size classes of bTP-1 (Mr, 22,000 and 24,000). Culture in presence of [ 35 S]methionine and tunicamycin gave rise to a nonglycosylated form of bTP-1 with an apparent Mr of 18,000. Treatment of [ 35 S]methionine-labeled bTP-1 with either endoglycosidase-H or peptide:N-glycosidase F yielded products with Mr of 17,000 and 16,000, respectively. bTP-1, although functionally and structurally related to oTP-1, appears to be a glycoprotein carrying at least two Asn-linked oligosaccharides. Th e two Mr classes of bTP-1 arise as a result of differences in either the number or structure of the carbohydrate chains. Like oTP-1, bTP-1 is probably translated from multiple mRNA species. © 1988 by The Endocrine Society.

author list (cited authors)
Anthony, R. V., Helmer, S. D., Sharif, S. F., Roberts, R. M., Hansen, P. J., Thatcher, W. W., & Bazer, F. W.
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  • RNA
  • Trophoblasts
  • Pregnancy Proteins
  • Pregnancy
  • Pregnancy, Animal
  • Organ Culture Techniques
  • Female
  • Cattle
  • Interferon Type I
  • RNA, Messenger
  • Animals
  • Protein Biosynthesis
  • Sheep
  • Molecular Weight
  • Species Specificity
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