Department of Biology of the Cell Nucleus, Institute of Molecular Genetics of the Czech Academy of Sciences, v.v.i., Prague 142 20, Czech Republic.
Department of Epigenetics of the Cell Nucleus, Institute of Molecular Genetics of the Czech Academy of Sciences, v.v.i., Division BIOCEV, Vestec 252 50, Czech Republic.
Int J Mol Sci. 2018 Sep 10;19(9):2679. doi: 10.3390/ijms19092679.
One of the most studied phosphoinositides is phosphatidylinositol 4,5-bisphosphate (PIP2), which localizes to the plasma membrane, nuclear speckles, small foci in the nucleoplasm, and to the nucleolus in mammalian cells. Here, we show that PIP2 also localizes to the nucleus in prophase I, during the gametogenesis of hermaphrodite. The depletion of PIP2 by type I PIP kinase (PPK-1) kinase RNA interference results in an altered chromosome structure and leads to various defects during meiotic progression. We observed a decreased brood size and aneuploidy in progeny, defects in synapsis, and crossover formation. The altered chromosome structure is reflected in the increased transcription activity of a tightly regulated process in prophase I. To elucidate the involvement of PIP2 in the processes during the development, we identified the PIP2-binding partners, leucine-rich repeat (LRR-1) protein and proteasome subunit beta 4 (PBS-4), pointing to its involvement in the ubiquitin⁻proteasome pathway.
研究最多的磷酸肌醇之一是磷脂酰肌醇 4,5-二磷酸（PIP2），它定位于质膜、核斑点、核质中的小焦点和哺乳动物细胞核仁。在这里，我们表明 PIP2 在有性生殖过程中的前期 I 也定位于核内。通过 I 型 PIP 激酶（PPK-1）激酶 RNA 干扰耗尽 PIP2 会导致染色体结构改变，并导致减数分裂过程中的各种缺陷。我们观察到后代的繁殖力下降和非整倍体、联会和交叉形成缺陷。改变的染色体结构反映在前期 I 中严格调控过程的转录活性增加。为了阐明 PIP2 在发育过程中的作用，我们鉴定了 PIP2 的结合伴侣，富含亮氨酸重复（LRR-1）蛋白和蛋白酶体亚基β4（PBS-4），表明其参与了泛素-蛋白酶体途径。
