The A and B forms of the chicken progesterone receptor arise by alternate initiation of translation of a unique mRNA

Biochem Biophys Res Commun. 1987 Dec 16;149(2):493-501. doi: 10.1016/0006-291x(87)90395-0.


In order to establish the origin of the A and B proteins of the chicken progesterone receptor we have expressed its cDNA in vivo in heterologous cells and in vitro in reticulocyte cell lysates. The A and B proteins were expressed from a single cDNA both in heterologous receptor negative cells and in a cell-free system. Both proteins bind progesterone and are indistinguishable from chick oviduct authentic A and B proteins in terms of size, immunoreactivity and hormone binding properties. Truncated mRNA's which lack the receptor B protein translation signal are capable of generating the receptor A protein by initiation of translation at a second internal start site. We conclude from these data that the chicken progesterone receptor A and B proteins arise most likely by alternate initiation of translation from a single mRNA transcript.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Chickens
  • Gene Expression Regulation
  • Protein Biosynthesis*
  • RNA, Messenger / metabolism*
  • Receptors, Progesterone / biosynthesis*
  • Receptors, Progesterone / genetics
  • Receptors, Progesterone / immunology
  • Transcription, Genetic


  • RNA, Messenger
  • Receptors, Progesterone