The Glial Cell-Derived Neurotrophic Factor (GDNF)-responsive Phosphoprotein Landscape Identifies Raptor Phosphorylation Required for Spermatogonial Progenitor Cell Proliferation
The Glial Cell-Derived Neurotrophic Factor (GDNF)-responsive Phosphoprotein Landscape Identifies Raptor Phosphorylation Required for Spermatogonial Progenitor Cell Proliferation
复制标题
胶质细胞源性神经营养因子 (GDNF) 响应性磷酸蛋白景观鉴定了精原祖细胞增殖所需的 Raptor 磷酸化
DOI：
10.1074/mcp.m116.065797
复制
发表时间：
2017-06-01
影响因子：
7
通讯作者：
Wu, Xin
中科院分区：
文献类型：
--
作者：
Wang, Min;Guo, Yueshuai;Wu, Xin
干细胞的细胞因子依赖性更新是组织稳态和再生的基本要求。精原祖细胞（SPC），包括干细胞支持终身精子发生和男性生育力，但关键的磷酸化事件，调节命运的决定SPC仍然没有得到解决。在这里，我们描述了定量质谱为基础的蛋白质组学和磷酸化蛋白质组学分析的SPC持续刺激与胶质细胞源性神经营养因子（GDNF），支持SPC增殖的外在因素。刺激的SPC含有3382个磷酸化蛋白和12141个磷酸化位点。其中，325个差异磷酸化蛋白和570个GDNF触发的磷酸化位点高度富集ERK 1/2，GSK 3，CDK 1和CDK 5磷酸化基序。我们验证了GDNF/ERK 1/2信号传导的抑制会损害SPC的增殖并增加G2/M细胞周期停滞。值得注意的是，我们发现SPC的增殖需要mTORC 1组分Raptor在Ser（863）的磷酸化。Raptor在小鼠生殖细胞中的组织特异性缺失导致精子发生受损和精原细胞的进行性丧失，但在体外，Raptor在SPC中的过度表达增加了Raptor的磷酸化，诱导了SPC在培养中更快的生长。这些研究结果涉及以前未描述的信号网络在管理的命运决定的SPC，这是必不可少的精子发生的理解和潜在的后果的致病性侮辱男性不育症。
Cytokine-dependent renewal of stem cells is a fundamental requisite for tissue homeostasis and regeneration. Spermatogonial progenitor cells (SPCs) including stem cells support life-long spermatogenesis and male fertility, but pivotal phosphorylation events that regulate fate decisions in SPCs remain unresolved. Here, we described a quantitative mass-spectrometry-based proteomic and phosphoproteomic analyses of SPCs following sustained stimulation with glial cell-derived neurotrophic factor (GDNF), an extrinsic factor supporting SPC proliferation. Stimulated SPCs contained 3382 identified phosphorylated proteins and 12141 phosphorylation sites. Of them, 325 differentially phosphorylated proteins and 570 phosphorylation sites triggered by GDNF were highly enriched for ERK1/2, GSK3, CDK1, and CDK5 phosphorylating motifs. We validated that inhibition of GDNF/ERK1/2-signaling impaired SPC proliferation and increased G2/M cell cycle arrest. Significantly, we found that proliferation of SPCs requires phosphorylation of the mTORC1 component Raptor at Ser(863). Tissue-specific deletion of Raptor in mouse germline cells results in impaired spermatogenesis and progressive loss of spermatogonia, but in vitro increased phosphorylation of Raptor by raptor over-expression in SPCs induced a more rapidly growth of SPCs in culture. These findings implicate previously undescribed signaling networks in governing fate decision of SPCs, which is essential for the understanding of spermatogenesis and of potential consequences of pathogenic insult for male infertility.