Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Hospital Research Centre, Winnipeg, MB, R2H 2A6, Canada.
J Steroid Biochem Mol Biol. 2019 Jul;191:105376. doi: 10.1016/j.jsbmb.2019.105376. Epub 2019 May 5.
Progesterone (P4) is a major steroid hormone that has important effects on metabolism. The progesterone receptor membrane component 1 (PGRMC1) is a non-canonical P4 binding protein. The biological functions affected by PGRMC1 include cholesterol/steroid biosynthesis and metabolism, iron homeostasis and heme trafficking, autophagy, regulation of cell cycle and proliferation, cell migration and invasion. PGRMC1 has been an attractive target for therapeutic intervention in cancer and neurodegenerative disorders due to its biological role in promoting cell survival. P4 has been used in a number of clinical applications and is considered neuroprotective. The involvement of PGRMC1 in P4-mediated regulation of cellular glucose metabolism is not well studied. PGRMC1 is a 21 kDa protein but complex post-translational modifications (PTMs) lead to the existence of several high molecular mass proteins whose molecular function, intracellular distribution, and physiological relevancies are not fully known. Therefore, in this study, P4-PGRMC1-mediated cellular glucose metabolism and PTMs of PGRMC1 were studied using wild-type and CRISPR/Cas9 mediated PGRMC1 knockout (KO) human embryonic kidney-derived (HEK293) cell lines. A 70 kDa (p70) and 100 kDa (p100) PGRMC1 proteins were identified that are predominantly associated with endoplasmic reticulum/mitochondria and nuclear fractions in the cells, respectively. Phosphorylation, acetylation, ubiquitination, and sumoylation of native PGRMC1 under serum starvation were identified which provided an explanation for the higher molecular masses. This study indicates that P4-PGRMC1 signaling caused a rapid increase in glycolysis in the presence of oxygen (aerobic glycolysis) and a corresponding decrease in cellular respiration, known as the Warburg effect. Further, it was demonstrated that the P4-induced increase in glycolysis is associated with rapid proteasomal degradation of the p70 and reduction of the nuclear p100 protein level. P4 treatment also caused significant alteration in the dynamics of PGRMC1 PTMs and its association with potential interacting proteins. Overall, this study provides a hitherto unknown aspect of P4-PGRMC1 mediated signaling that changes basic cellular metabolism in HEK293 cells.
孕酮（P4）是一种重要的类固醇激素，对代谢有重要影响。孕激素受体膜成分 1（PGRMC1）是非典型的 P4 结合蛋白。受 PGRMC1 影响的生物学功能包括胆固醇/类固醇生物合成和代谢、铁稳态和血红素转运、自噬、细胞周期和增殖的调节、细胞迁移和侵袭。由于其促进细胞存活的生物学作用，PGRMC1 一直是癌症和神经退行性疾病治疗干预的有吸引力的靶点。P4 已在许多临床应用中得到应用，并被认为具有神经保护作用。PGRMC1 在 P4 介导的细胞葡萄糖代谢调节中的作用尚未得到充分研究。PGRMC1 是一种 21kDa 的蛋白质，但复杂的翻译后修饰（PTMs）导致存在几种高分子质量的蛋白质，其分子功能、细胞内分布和生理相关性尚不完全清楚。因此，在这项研究中，使用野生型和 CRISPR/Cas9 介导的 PGRMC1 敲除（KO）人胚肾衍生（HEK293）细胞系研究了 P4-PGRMC1 介导的细胞葡萄糖代谢和 PGRMC1 的 PTMs。鉴定出 70kDa（p70）和 100kDa（p100）PGRMC1 蛋白，它们主要分别与细胞内的内质网/线粒体和核部分相关联。在血清饥饿下鉴定出天然 PGRMC1 的磷酸化、乙酰化、泛素化和 sumoylation，为较高的分子量提供了解释。这项研究表明，P4-PGRMC1 信号在有氧条件下（有氧糖酵解）导致糖酵解的快速增加，同时细胞呼吸相应减少，这被称为沃伯格效应。此外，研究表明，P4 诱导的糖酵解增加与快速蛋白酶体降解 p70 和减少核 p100 蛋白水平有关。P4 处理还导致 PGRMC1 PTMs 的动态及其与潜在相互作用蛋白的关联发生显著改变。总的来说，这项研究提供了 P4-PGRMC1 介导的信号转导的一个未知方面，改变了 HEK293 细胞的基本细胞代谢。
