Characterization of the adrenal-specific antigen IZA (inner zone antigen) and its role in the steroidogenesis
Autor: | Yasuki Nonaka, Hiroshi Takemori, Gavin P. Vinson, Yoshiko Katoh, Mitshuhiro Okamoto, Junko Doi, Li Min, Nanao Horike, Farah S. Raza, Hatano Osamu |
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Rok vydání: | 2004 |
Předmět: |
Receptors
Steroid Molecular Sequence Data Biology Biochemistry Endocrinology Zona fasciculata Antigen Adrenal Cortex Hormones Complementary DNA Progesterone receptor medicine Animals Humans Amino Acid Sequence Molecular Biology PGRMC1 Expression vector Sequence Homology Amino Acid Adrenal cortex Membrane Proteins Ligand (biochemistry) Molecular biology Zona Reticularis medicine.anatomical_structure Adrenal Cortex Zona Fasciculata Receptors Progesterone |
Zdroj: | Molecular and cellular endocrinology. 215(1-2) |
ISSN: | 0303-7207 |
Popis: | Inner zone antigen (IZA) is a protein specifically expressed in the zona fasciculata and reticularis of the adrenal cortex. The cDNA encoding IZA was found to be identical to that encoding the previously reported putative membrane-associated progesterone receptor (MPR) and the TCDD-induced 25 kDa protein (25-Dx). From its structure, MPR was classed as a member of a protein family containing a haem-binding domain, and progesterone was proposed to be a ligand of this domain. Indeed, when GST-tagged IZA was expressed in Escherichia coli and purified, the purified GST–IZA had a brown colour with maximum absorbance at 400 nm. The addition of dithionate shifted the absorbance peak to 420 nm, suggesting a haem-binding function. The possible role of IZA in steroidogenesis has been addressed, and the inhibition of adrenal steroidogenesis by the addition of an anti-IZA monoclonal antibody has been reported. When COS-7 cells were transformed with plasmids for appropriate steroidogenic enzymes in the presence or absence of an IZA expression plasmid and tested for their steroidogenic activities, 21-hydroxylation of progesterone was found to be specifically activated by IZA overexpression, suggesting the involvement of IZA in progesterone metabolism. Taken together, the available evidence suggests that IZA may have an important role in the functions of the adrenal zona fasciculata and reticularis. |
Databáze: | OpenAIRE |
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