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Browsing by Subject "Spermatogenesis"
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Item Epigenetic regulator Cfp1 safeguards male meiotic progression by regulating meiotic gene expression(Springer Nature, 2022) Ki, Byeong Seong; Shim, Sung Han; Park, Chanhyeok; Yoo, Hyunjin; La, Hyeonwoo; Lee, Ok-Hee; Kwon, Youngjoo; Skalnik, David G.; Okada, Yuki; Yoon, Ho-Geun; Kim, Jin-Hoi; Hong, Kwonho; Choi, Youngsok; Biology, School of ScienceMeiosis occurs specifically in germ cells to produce sperm and oocytes that are competent for sexual reproduction. Multiple factors are required for successful meiotic entry, progression, and termination. Among them, trimethylation of histone H3 on lysine 4 (H3K4me3), a mark of active transcription, has been implicated in spermatogenesis by forming double-strand breaks (DSBs). However, the role of H3K4me in transcriptional regulation during meiosis remains poorly understood. Here, we reveal that mouse CXXC finger protein 1 (Cfp1), a component of the H3K4 methyltransferase Setd1a/b, is dynamically expressed in differentiating male germ cells and safeguards meiosis by controlling gene expression. Genetic ablation of mouse CFP1 in male germ cells caused complete infertility with failure in prophase I of the 1st meiosis. Mechanistically, CFP1 binds to genes essential for spermatogenesis, and its loss leads to a reduction in H3K4me3 levels and gene expression. Importantly, CFP1 is highly enriched within the promoter/TSS of target genes to elevate H3K4me3 levels and gene expression at the pachytene stage of meiotic prophase I. The most enriched genes were associated with meiosis and homologous recombination during the differentiation of spermatocytes to round spermatids. Therefore, our study establishes a mechanistic link between CFP1-mediated transcriptional control and meiotic progression and might provide an unprecedented genetic basis for understanding human sterility.Item Phosphatase of regenerating liver 2 (PRL2) deficiency impairs Kit signaling and spermatogenesis(ASBMB, 2014-02-07) Dong, Yuanshu; Zhang, Lujuan; Bai, Yunpeng; Zhou, Hong-Ming; Campbell, Amanda M.; Chen, Hanying; Yong, Weidong; Zhang, Wenjun; Zeng, Qi; Shou, Weinian; Zhang, Zhong-Yin; Department of Biochemistry & Molecular Biology, IU School of MedicineThe Phosphatase of Regenerating Liver (PRL) proteins promote cell signaling and are oncogenic when overexpressed. However, our understanding of PRL function came primarily from studies with cultured cell lines aberrantly or ectopically expressing PRLs. To define the physiological roles of the PRLs, we generated PRL2 knock-out mice to study the effects of PRL deletion in a genetically controlled, organismal model. PRL2-deficient male mice exhibit testicular hypotrophy and impaired spermatogenesis, leading to decreased reproductive capacity. Mechanistically, PRL2 deficiency results in elevated PTEN level in the testis, which attenuates the Kit-PI3K-Akt pathway, resulting in increased germ cell apoptosis. Conversely, increased PRL2 expression in GC-1 cells reduces PTEN level and promotes Akt activation. Our analyses of PRL2-deficient animals suggest that PRL2 is required for spermatogenesis during testis development. The study also reveals that PRL2 promotes Kit-mediated PI3K/Akt signaling by reducing the level of PTEN that normally antagonizes the pathway. Given the strong cancer susceptibility to subtle variations in PTEN level, the ability of PRL2 to repress PTEN expression qualifies it as an oncogene and a novel target for developing anti-cancer agents.Item Role of phosphatase of regenerating liver 1 (PRL1) in spermatogenesis(SpringerNature, 2016-09-26) Bai, Yunpeng; Zhou, Hong-Ming; Zhang, Lujuan; Dong, Yuanshu; Zeng, Qi; Shou, Weinian; Zhang, Zhong-Yin; Department of Biochemistry & Molecular Biology, IU School of MedicineThe PRL phosphatases are oncogenic when overexpressed but their in vivo biological function is less well understood. Previous gene deletion study revealed a role for PRL2 in spermatogenesis. We report here the first knockout mice lacking PRL1, the most related homolog of PRL2. We found that loss of PRL1 does not affect spermatogenesis and reproductive ability of male mice, likely due to functional compensation by the relatively higher expression of PRL2 in the testes. However, PRL1-/-/PRL2+/- male mice show testicular atrophy phenotype similar to PRL2-/- mice. More strikingly, deletion of one PRL1 allele in PRL2-/- male mice causes complete infertility. Mechanistically, the total level of PRL1 and PRL2 is negatively correlated with the PTEN protein level in the testis and PRL1+/-/PRL2-/- mice have the highest level of PTEN, leading to attenuated Akt activation and increased germ cell apoptosis, effectively halting spermatozoa production. These results provide the first evidence that in addition to PRL2, PRL1 is also required for spermatogenesis by downregulating PTEN and promoting Akt signaling. The ability of the PRLs to suppress PTEN expression underscores the biochemical basis for their oncogenic potential.