Seladin-1 expression in rat adrenal gland: effect of adrenocorticotropic hormone treatment.
Seladin-1 (KIAA0018) gene is the seventh most highlyexpressed gene in the adult adrenal gland, along with genes coding for steroidogenic enzymes. The aim of the present study was to investigate the localization of the Seladin-1 protein in control and ACTH-treated rat adrenal glands and to verify whether Seladin-1 is involved in secretion. Immunofluorescence studies revealed that Seladin-1 was localized principally in the zona fasciculata, cytoplasm, and nucleus. Expression of Seladin-1 was increased by ACTH treatment, in vivo and in culture conditions. Subcellular fractionation offasciculata cells showed that Seladin-1 was mainly present in the nucleus, membrane, and cytoskeleton fractions and, to a lesser extent, in the cytosol. ACTH treatment decreased Seladin-1 expression in the cytosol, with a concomitant increase in the nuclear fraction. In the glomerulosa and fasciculata cells in culture, ACTH induced a relocalization of Seladin-1 into specific nuclear regions. This ACTH-induced relocalization was abrogated by the pre-treatment of cells with 75 nM U18666A (an inhibitor of Seladin-1). In addition, fasciculata cells exhibited an increase in the basal level of steroid secretion when cultured in the presence of U18666A (25 and 75 nM), although ACTH-induced secretion was decreased. In summary, the present study demonstrates that the protein expression of Seladin-1 is more abundant in fasciculata cells than in glomerulosa cells and that the ACTH treatment increases both expression and nuclear localization of the protein. Results also suggest that depending on its cellular localization, the Delta24-reductase activity of Seladin-1 may play a major role in steroid secretion in the adrenal gland.
Battista
Marie-Claude
MC
Service of Endocrinology, Department of Medicine, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, 3001, Sherbrooke, Quebec, Canada.
Roberge
Claude
C
Otis
Mélissa
M
Gallo-Payet
Nicole
N
D000311:Adrenal Glands / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000450:Aldosterone / Q000032:analysis / Q000378:metabolism; D000736:Androstenes / Q000494:pharmacology; D000818:Animals; D015153:Blotting, Western / Q000379:methods; D002467:Cell Nucleus / Q000737:chemistry; D049109:Cell Proliferation; D002478:Cells, Cultured; D003345:Corticosterone / Q000032:analysis / Q000378:metabolism; D003593:Cytoplasm / Q000737:chemistry; D017931:DNA Primers; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005455:Fluorescent Antibody Technique; D015870:Gene Expression / Q000187:drug effects; D007106:Immune Sera / Q000302:isolation & purification; D009419:Nerve Tissue Proteins / Q000032:analysis* / Q000235:genetics / Q000276:immunology; D044925:Oxidoreductases Acting on CH-CH Group Donors / Q000032:analysis* / Q000235:genetics / Q000276:immunology; D011897:Random Allocation; D051381:Rats; D011919:Rats, Inbred Strains; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015383:Zona Fasciculata / Q000737:chemistry
D000736:Androstenes; D017931:DNA Primers; D004791:Enzyme Inhibitors; D007106:Immune Sera; D009419:Nerve Tissue Proteins; C006261:3-beta-(2-(diethylamino)ethoxy)androst-5-en-17-one; D000450:Aldosterone; D000324:Adrenocorticotropic Hormone; C000600134:DHCR24 protein, rat; D044925:Oxidoreductases Acting on CH-CH Group Donors; D003345:Corticosterone