RFX2 is a potential transcriptional regulatory factor for histone H1t and other genes expressed during the meiotic phase of spermatogenesis
RFX2 is a potential transcriptional regulatory factor for histone H1t and other genes expressed during the meiotic phase of spermatogenesis
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DOI：
10.1095/biolreprod.104.032268
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发表时间：
2004-11-01
影响因子：
3.6
通讯作者：
Kistler, MK
中科院分区：
文献类型：
--
作者：
Horvath, GC;Kistler, WS;Kistler, MK
H1t是在粗线期中晚期精母细胞中合成的一种新的连接蛋白变体。它的调控区域是有趣的，因为发育特异性表达已经在一个无处不在的表达启动子上留下了印象。利用竞争性带移分析和特异性抗血清，我们现在已经证明H1t-60 CCTAGG回文基序区域与RFX转录调节因子家族的成员结合。睾丸特异性结合复合体含有RFX2，可能是同型二聚体。从睾丸和躯体器官获得的其他dna -蛋白复合物含有RFX1，主要作为异源二聚体。Western blots证实RFX2在成年睾丸中的表达显著增强，RFX2在高富集的晚期粗线精母细胞和圆形精母细胞中表达同样显著。小鼠睾丸免疫组化显示，RFX2在粗粒精母细胞中表达强烈，在早期圆形精母细胞中表达较高，仅在核凝聚前表达下降。最大表达量与H1t的出现密切相关。相比之下，生殖细胞中的RFX1免疫反应性仅在晚期圆形精子中检测到。使用睾丸核提取物或体外合成的RFX2，还鉴定了小鼠层粘连蛋白C2和Sgy启动子的rfx特异性带复合物。这些结果引起人们的关注，RFX2作为一个转录因子，在减数分裂和精子早期发育过程中具有明显的基因表达调控潜力。
H1t is a novel linker histone variant synthesized in mid- to late pachytene spermatocytes. Its regulatory region is of interest because developmentally specific expression has been impressed on an otherwise ubiquitously expressed promoter. Using competitive band-shift assays and specific antisera, we have now shown that the H1t-60 CCTAGG palindrome motif region binds members of the RFX family of transcriptional regulators. The testis-specific binding complex contains RFX2, probably as a homodimer. Other DNA-protein complexes obtained from testis as well as somatic organs contain RFX1, primarily as a heterodimer. Western blots confirmed that RFX2 expression is greatly enhanced in adult testis and that RFX2 is equally prominent in highly enriched populations of late pachytene spermatocytes and round spermatids. Immunohistochemistry carried out on mouse testis showed that RFX2 is strongly expressed in pachytene spermatocytes, remains high in early round spermatids, and declines only in advance of nuclear condensation. Maximum expression correlates well with the appearance of H1t. In contrast, RFX1 immunoreactivity in germ cells was only detected in late round spermatids. RFX-specific band complexes were also identified for both the mouse lamin C2 and Sgy promoters, using either testis nuclear extracts or in vitro-synthesized RFX2. These results call attention to RFX2 as a transcription factor with obvious potential for the regulation of gene expression during meiosis and the early development of spermatids.