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The transactivation‐competent carboxyl‐terminal domain of AF‐9 is expressed within a sexually dimorphic transcript in rat pituitary
Author(s) -
Morgan Helen,
Smith Martin,
Burke Zoe,
Carter David
Publication year - 2000
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.14.9.1109
Subject(s) - transactivation , biology , open reading frame , anterior pituitary , gene , complementary dna , gene expression , messenger rna , population , microbiology and biotechnology , genetics , endocrinology , peptide sequence , hormone , medicine , environmental health
We have investigated the biological role of the cellular counterpart of the leukemogenic AF‐9 gene by cloning the rat AF‐9 (rAF‐9) cDNA and defining the regulation of an anterior pituitary‐specific rAF‐9 transcript that is expressed in a sexually dimorphic manner. Expression of this transcript is down‐regulated after puberty in females and can be subsequently up‐regulated in adults by ovariectomy. Hormone replacement studies have provided direct evidence that rAF‐9 mRNA expression is suppressed by estrogen. Mapping the 1.9 kb anterior pituitary transcript has shown that it corresponds in size to the rAF‐9 cDNA clone, which contains an open reading frame (ORF) that is truncated compared with the human AF‐9 ORF, but encodes a previously defined transcriptional activation domain. Thus, the cellular AF‐9 gene is alternatively expressed in a manner that reflects the presence of translocated, functionally active (oncogenic) AF‐9 sequences in leukemias. Using a novel antisera raised against a rAF‐9 peptide, we have also demonstrated tissue‐ and sex‐specific expression of a nuclear 41 kDa anterior pituitary protein and have localized this protein to a major population of growth hormone synthesizing cells. By localizing the expression and defining the physiological regulation of rAF‐9, our studies have provided novel insights into the AF‐9 gene that will facilitate an understanding of both oncogenic and endocrine roles.—Morgan, H., Smith, M., Burke, Z., Carter, D. The transactivation‐competent carboxyl‐terminal domain of AF‐9 is expressed within a sexually dimorphic transcript in rat pituitary. FASEB J. 14, 1109–1116 (2000)