Cloning, expression and regulation of chicken ovalbumin upstream promoter transcription factors (COUP-TFII and EAR-2) in the rat anterior pituitary gland

• Published in: Neuroendocrinology Vol. 82; no. 5-6; p. 233
• Main Authors: Raccurt, Mireille, Smallwood, Sébastien, Mertani, Hichem C, Devost, Dominic, Abbaci, Khédidja, Boutin, Jean-Marie, Morel, Gérard
• Format: Journal Article
• Language: English
• Published: Switzerland 01-01-2005
• Subjects: Amino Acid Sequence; Animals; Blotting, Western; Cell Differentiation - physiology; Cell Proliferation; Cloning, Molecular; COUP Transcription Factor II - analysis; COUP Transcription Factor II - genetics; COUP Transcription Factor II - immunology; COUP Transcription Factor II - physiology; DNA, Complementary - analysis; DNA, Complementary - genetics; Electrophoresis, Polyacrylamide Gel; Female; Gene Expression Regulation - physiology; Immunohistochemistry; Male; Molecular Sequence Data; Pituitary Gland, Anterior - chemistry; Pituitary Gland, Anterior - cytology; Pituitary Gland, Anterior - metabolism; Pituitary Gland, Anterior - physiology; Pregnancy; Pregnancy, Animal - genetics; Pregnancy, Animal - physiology; Prolactin - analysis; Prolactin - genetics; Prolactin - physiology; Rats; Rats, Wistar; Receptors, Steroid - analysis; Receptors, Steroid - genetics; Receptors, Steroid - immunology; Receptors, Steroid - physiology; Transcription Factors - analysis; Transcription Factors - genetics; Transcription Factors - immunology; Transcription Factors - physiology
• ISSN: 0028-3835
• DOI: 10.1159/000092752

Chicken ovalbumin upstream promoter transcription factors (COUP-TF)-II (NR2F2) and EAR-2 (NR2F6) are structurally related orphan members of the nuclear receptors superfamily. There are growing evidences that these factors play important roles during processes of differentiation and proliferation of several tissues. To better understand their role in the differentiated adult rat pituitary gland, we cloned COUP-TFII and EAR-2 cDNAs from an anterior pituitary cDNA library. Subsequently, we raised and characterized specific antibodies to the N-terminal domain of both nuclear receptors. We next examined their cellular and subcellular distribution in the pituitary gland and determined their regulation during pregnancy. COUP-TFII and EAR-2 pituitary genes display, respectively, 90 and 100% homologies with their human and mouse homologues. Cellular expression of both nuclear receptors was mainly detected in the lactotropes of male and female rats, with a prominent distribution in the nuclear compartment for EAR-2, and interestingly both proteins were significantly upregulated in pituitaries of pregnant vs. cycling female rats. Thus, our results have characterized cloning of rat pituitary COUP-TFII and EAR-2 genes, demonstrated that they are both specifically expressed in lactotropes, and strongly suggested that they may play an important role in modulating prolactin (PRL) gene expression during pregnancy.