Open AccessIdentification and characterization of the minimal androgen‐regulated kidney‐specific kidney androgen‐regulated protein gene promoter
Author(s) -
Fan Liqiang,
Hardy Dianne O,
Catteral James F,
Zhao Jian,
Li Suxia
Publication year - 2008
Publication title -
acta biochimica et biophysica sinica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.771
H-Index - 57
eISSN - 1745-7270
pISSN - 1672-9145
DOI - 10.1111/j.1745-7270.2008.00482.x
Subject(s) - androgen , androgen receptor , dihydrotestosterone , reporter gene , biology , kidney , transfection , microbiology and biotechnology , basal (medicine) , endocrinology , medicine , gene , gene expression , biochemistry , genetics , hormone , prostate cancer , cancer , insulin
The kidney androgen‐regulated protein ( Kap ) gene is tissue specific and regulated by androgen in mouse kidney proximal tubule cells (PTCs). In the present study, we aimed to identify the minimal PTC‐specific androgen‐regulated Kap promoter and analyze its androgen response elements (AREs). A deletion series of the Kap 1542 promoter/luciferase constructs were assayed in opossum kidney (OK) PTCs in the presence or absence of 15 nM dihydrotestosterone (DHT). Kap 1542 and Kap 637 had low activity and no androgen induction; Kap 224 had a basal activity that was 4‐ to 5‐fold higher than that of Kap 1542, but was only slightly induced by DHT. Kap 147 had a basal activity that was 2‐ to 3‐fold higher than that of Kap 1542 and was induced by DHT 4‐ to 6‐fold. Kap 77 abolished basal promoter activity but was still induced by DHT. Results showed that, in vitro , Kap 147 was a minimal androgen‐regulated promoter. Transient transfection in different cells demonstrated that Kap 147 specifically initiated reporter gene expression in PTCs. Sequence analysis revealed two potential AREs located at positions −124 and −39 of Kap 147. Mutational assays showed that only the ARE at −124 was involved in androgen response in OK cells. Electrophoretic mobility shift assay also verified −124 ARE bound specifically to androgen receptor. In conclusion, we defined the minimal Kap 147 promoter that may be a good model for the study of kidney PTC‐specific expression and molecular mechanisms that lead to an androgen‐specific responsiveness in vivo.