DNA demethylation-dependent AR recruitment and GATA factors drive Rhox5 homeobox gene transcription in the epididymis.
Mammalian male fertility depends on the epididymis, a highly segmented organ that promotes sperm maturation and protects sperm from oxidative damage. Remarkably little is known about how gene expression is controlled in the epididymis. A candidate to regulate genes crucial for epididymal function is reproductive homeobox gene on X chromosome (RHOX)5, a homeobox transcription factor essential for optimal sperm motility that is expressed in the caput region of the epididymis. Here, we report the identification of factors that control Rhox5 gene expression in epididymal cells in a developmentally regulated and region-specific fashion. First, we identify GATA transcription factor-binding sites in the Rhox5 proximal promoter (Pp) necessary for Rhox5 expression in epididymal cells in vitro and in vivo. Adjacent to the GATA sites are androgen-response elements, which bind to the nuclear hormone receptor androgen receptor (AR), and are responsible for the AR-dependent expression of Rhox5 in epididymal cells. We provide evidence that AR is recruited to the Pp in a region-specific and developmentally regulated manner in the epididymis that is dictated not only by differential AR availability but differential methylation of the Pp. Site-specific methylation of the Pp cytosine and guanine separated by one phosphate, most of which overlap with androgen-response elements, inhibited both AR occupancy at the Pp and Pp-dependent transcription in caput epididymal cells. Together, our data support a model in which DNA methylation, AR, and GATA factors collaborate to dictate the unique developmental and region-specific expression pattern of the RHOX5 homeobox transcription factor in the caput epididymis, which in turn controls the expression of genes critical for promoting sperm motility and function.
Department of Biochemistry and Molecular Biology, The University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030, USA.
Anjana
A
Bhardwaj
Hye-Won
HW
Song
Marcy
M
Beildeck
Stefanie
S
Kerkhofs
Ryan
R
Castoro
Sreenath
S
Shanker
Karel
K
De Gendt
Kichiya
K
Suzuki
Frank
F
Claessens
Jean Pierre
JP
Issa
Marie-Claire
MC
Orgebin-Crist
Miles F
MF
Wilkinson
D000728:Androgens / Q000502:physiology; D000818:Animals; D002460:Cell Line; D019175:DNA Methylation; D004822:Epididymis / Q000378:metabolism*; D050980:GATA Transcription Factors / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D008156:Luciferases / Q000096:biosynthesis / Q000235:genetics; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009928:Organ Specificity; D011944:Receptors, Androgen / Q000235:genetics / Q000378:metabolism*; D020218:Response Elements; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic
D000728:Androgens; D050980:GATA Transcription Factors; D018398:Homeodomain Proteins; D011944:Receptors, Androgen; C490383:Rhox5 protein, rat; D014157:Transcription Factors; D008156:Luciferases