Endocrinology, Vol 123, 1274-1280, Copyright © 1988 by Endocrine Society

ARTICLES

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

RV Anthony, SD Helmer, SF Sharif, RM Roberts, PJ Hansen, WW Thatcher and FW Bazer
Department of Animal Science, University of Missouri, Columbia 65211.

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 5.4-5.7), 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 6.3-6.8). Cell-free translation of ovine conceptus mRNA yields pre-oTP-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 [3H]glucosamine or [3H]mannose incorporate label into both size classes of bTP-1 (Mr, 22,000 and 24,000). Culture in presence of [35S]methionine and tunicamycin gave rise to a nonglycosylated form of bTP-1 with an apparent Mr of 18,000. Treatment of [35S]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. The 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.

This article has been cited by other articles:

				T. Ezashi, P. Das, R. Gupta, A. Walker, and R. M. Roberts The Role of Homeobox Protein Distal-Less 3 and Its Interaction with ETS2 in Regulating Bovine Interferon-Tau Gene Expression-Synergistic Transcriptional Activation with ETS2 Biol Reprod, July 1, 2008; 79(1): 115 - 124. [Abstract] [Full Text] [PDF]

				M. L. Mussard, C. R. Burke, E. J. Behlke, C. L. Gasser, and M. L. Day Influence of premature induction of a luteinizing hormone surge with gonadotropin-releasing hormone on ovulation, luteal function, and fertility in cattle J Anim Sci, April 1, 2007; 85(4): 937 - 943. [Abstract] [Full Text] [PDF]

				M. D. Glover and G. E. Seidel Jr Increased Messenger RNA for Allograft Inflammatory Factor-1, LERK-5, and a Novel Gene in 17.5-Day Relative to 15.5-Day Bovine Embryos Biol Reprod, September 1, 2003; 69(3): 1002 - 1012. [Abstract] [Full Text] [PDF]

				A. D. Ealy, S. F. Larson, L. Liu, A. P. Alexenko, G. L. Winkelman, H. M. Kubisch, J. A. Bixby, and R. M. Roberts Polymorphic Forms of Expressed Bovine Interferon-{{tau}} Genes: Relative Transcript Abundance during Early Placental Development, Promoter Sequences of Genes and Biological Activity of Protein Products Endocrinology, July 1, 2001; 142(7): 2906 - 2915. [Abstract] [Full Text] [PDF]

				G. D. Niswender, J. L. Juengel, P. J. Silva, M. K. Rollyson, and E. W. McIntush Mechanisms Controlling the Function and Life Span of the Corpus Luteum Physiol Rev, January 1, 2000; 80(1): 1 - 29. [Abstract] [Full Text] [PDF]

				G. L. Winkelman, R. M. Roberts, A. James Peterson, A. P. Alexenko, and A. D. Ealy Identification of the Expressed Forms of Ovine Interferon-Tau in the Periimplantation Conceptus: Sequence Relationships and ComparativeBiological Activities Biol Reprod, December 1, 1999; 61(6): 1592 - 1600. [Abstract] [Full Text]