Binding of RFX2 and NF-Y to the testis-specific histone H1t promoter may be required for transcriptional activation in primary spermatocytes.
The testis-specific linker histone H1t is transcribed exclusively in pachytene spermatocytes during spermatogenesis. The H1t promoter contains two imperfect inverted repeats which together comprise the X-box motif that is known to bind the transcription factor regulatory factor X (RFX). Out of all the histone H1 family promoters this motif appears only in the H1t promoter and may contribute to H1t tissue-specific expression. We show by Western blotting, EMSA, ChIP analysis, and real-time RT-PCR that the rat H1t X-box is bound by RFX2 in vivo in spermatocytes. We demonstrate that transcription factor NF-Y binds to the CCAAT-box motif that is located downstream and adjacent to the X-box and that testis NF-Y interacts either directly or indirectly with RFX2. Furthermore, we show that both the X-box and CCAAT-box are required for promoter activity and that co-expression of RFX2 greatly enhances testis histone H1t promoter activity in the GC-1spg germinal cell line.
VanWert
Jane M
JM
Research Service (151), Overton Brooks Veterans Administration Medical Center, Shreveport, Louisiana 71101-4295, USA.
Wolfe
Steven A
SA
Grimes
Sidney R
SR
D020816:Amino Acid Motifs; D000818:Animals; D023081:CCAAT-Binding Factor / Q000378:metabolism*; D002843:Chromatin / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005822:Genetic Vectors; D006657:Histones / Q000378:metabolism*; D008297:Male; D011401:Promoter Regions, Genetic; D051381:Rats; D017207:Rats, Sprague-Dawley; D000071701:Regulatory Factor X Transcription Factors; D013090:Spermatocytes / Q000166:cytology / Q000378:metabolism*; D013091:Spermatogenesis; D013737:Testis / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*; D015533:Transcriptional Activation
D023081:CCAAT-Binding Factor; D002843:Chromatin; D004268:DNA-Binding Proteins; D006657:Histones; C101059:RFX2 protein, human; D000071701:Regulatory Factor X Transcription Factors; D014157:Transcription Factors; C402244:nuclear factor Y