A Novel Role for Progesterone Receptor Membrane Component 1 (PGRMC1): A Partner and Regulator of Ferrochelatase.
A Novel Role for Progesterone Receptor Membrane Component 1 (PGRMC1): A Partner and Regulator of Ferrochelatase.
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孕激素受体膜成分1（PGRMC1）的新作用：铁螯合酶的伴侣和调节剂。
DOI：
10.1021/acs.biochem.6b00756
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发表时间：
2016-09-20
期刊：
影响因子：
2.9
通讯作者：
Medlock AE
中科院分区：
文献类型：
--
作者：
Piel RB 3rd;Shiferaw MT;Vashisht AA;Marcero JR;Praissman JL;Phillips JD;Wohlschlegel JA;Medlock AE
血红素是一种含铁的辅因子，对多种细胞过程和基本活动（如氧转运）至关重要。为了更好地了解血红素合成的手段，在红细胞生成过程中进行调节，亲和纯化结合质谱（MS）进行鉴定推定的蛋白质伴侣与亚铁螯合酶（FECH），血红素生物合成途径中的末端酶相互作用。在这些实验中鉴定了孕酮受体膜组分1（PGRMC 1）和孕酮受体膜组分2（PGRMC 2）。这些相互作用通过相互亲和纯化，然后通过MS分析和免疫印迹进行验证。在体外和HEK 293 T细胞（一种非红系细胞系）中证实了PGRMC 1和FECH之间的相互作用。当用PGRMC 1的小分子抑制剂AG-205处理作为红系分化的公认模型的细胞时，相对于未处理的细胞，观察到血红蛋白化降低。在体外血红素转移实验表明，纯化的PGRMC 1能够捐赠血红素脱辅基细胞色素b5。在PGRMC 1的存在下，体外测量的FECH活性以剂量依赖性方式降低。FECH和PGRMC 1之间的相互作用是最强的FECH的构象与产品的释放，这表明PGRMC 1可能通过控制血红素释放调节FECH的活性。总体而言，这些数据说明了PGRMC 1通过与FECH的相互作用在调节血红素合成中的作用，并表明PGRMC 1可能是血红素伴侣或传感器。
Heme is an iron containing cofactor essential for multiple cellular processes and fundamental activities such as oxygen transport. To better understand the means by which heme synthesis is regulated during erythropoiesis, affinity purification coupled with mass spectrometry (MS) was carried out to identify putative protein partners interacting with ferrochelatase (FECH), the terminal enzyme in the heme biosynthetic pathway. Both Progesterone Receptor Membrane Component 1 (PGRMC1) and Progesterone Receptor Membrane Component 2 (PGRMC2) were identified in these experiments. These interactions were validated by reciprocal affinity purification followed by MS analysis and immunoblotting. The interaction between PGRMC1 and FECH was confirmed in vitro and in HEK293T cells, a non-erythroid cell line. When cells that are recognized models for erythroid differentiation were treated with a small molecule inhibitor of PGRMC1, AG-205, there was an observed decrease in hemoglobinization relative to untreated cells. In vitro heme transfer experiments showed that purified PGRMC1 was able to donate heme to apo-cytochrome b5. In the presence of PGRMC1 in vitro measured FECH activity decreased in a dose dependent manner. Interactions between FECH and PGRMC1 were strongest for the conformation of FECH associated with product release suggesting that PGRMC1 may regulate FECH activity by controlling heme release. Overall, the data illustrate a role for PGRMC1 in regulating heme synthesis via interactions with FECH and suggest that PGRMC1 may be a heme chaperone or sensor.