Work

Evolution of Placenta-Specific Gene Expression: Comparison of the Equine and Human Gonadotropin α-Subunit Genes

Year: 1991

Type: article

Abstract: Primate and equine species are thought to be unique among mammals in synthesizing placental gonadotropin glycoprotein hormones. Human chorionic gonadotropin (CG) and equine pregnant mare's serum gonadotropin (PMSG) are produced in placenta by the specific activation of a glycoprotein hormone alpha-subunit gene and a corresponding beta-subunit gene. The evolutionary mechanisms for the apparently independent acquisition of tissue specificity were investigated by cloning the 5' flanking region of the equine alpha-subunit gene and comparing the DNA elements and trans-acting factors involved in placental expression. We find that though the equine gene is expressed and induced by cAMP, it does not contain the elements known to confer tissue-specific expression to the human gene, the cAMP response element (CRE) and the trophoblast-specific element (TSE), nor does it bind to the trans-acting factors CREB and TSEB. Instead, an additional factor (alpha-ACT) is found which binds to the equine and human, but not the murine, alpha-subunit genes in a region between the positions of the CRE and TSE and confers cAMP responsiveness.

Source: Molecular Endocrinology

DOI: 10.1210/mend-5-2-243

Authors: David J. Steger, Joachim Altschmied, Marita Buscher, Pamela L. Mellon

Institutions: Salk Institute for Biological Studies, University of California San Diego

Language: English

Topic: Genomics and Chromatin Dynamics

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: bronze

Funders: National Institutes of Health, Eunice Kennedy Shriver National Institute of Child Health and Human Development

Awards: GLYCOPROTEIN HORMONE A SUBUNIT GENE TRANSCRIPTION, G5064782656, G5271433374, Molecular Mechanisms of Gonadotrope Differentiation