Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
Cells. 2022 Nov 4;11(21):3496. doi: 10.3390/cells11213496.
: The 14-3-3 protein family is known to interact with many proteins in non-cardiac cell types to regulate multiple signaling pathways, particularly those relating to energy and protein homeostasis; and the 14-3-3 network is a therapeutic target of critical metabolic and proteostatic signaling in cancer and neurological diseases. Although the heart is critically sensitive to nutrient and energy alterations, and multiple signaling pathways coordinate to maintain the cardiac cell homeostasis, neither the structure of cardiac 14-3-3 protein interactome, nor potential functional roles of 14-3-3 protein-protein interactions (PPIs) in heart has been explored. : To establish the comprehensive landscape and characterize the functional role of cardiac 14-3-3 PPIs. : We evaluated both RNA expression and protein abundance of 14-3-3 isoforms in mouse heart, followed by co-immunoprecipitation of 14-3-3 proteins and mass spectrometry in left ventricle. We identified 52 proteins comprising the cardiac 14-3-3 interactome. Multiple bioinformatic analyses indicated that more than half of the proteins bound to 14-3-3 are related to mitochondria; and the deduced functions of the mitochondrial 14-3-3 network are to regulate cardiac ATP production via interactions with mitochondrial inner membrane proteins, especially those in mitochondrial complex I. Binding to ribosomal proteins, 14-3-3 proteins likely coordinate protein synthesis and protein quality control. Localizations of 14-3-3 proteins to mitochondria and ribosome were validated via immunofluorescence assays. The deduced function of cardiac 14-3-3 PPIs is to regulate cardiac metabolic homeostasis and proteostasis. : Thus, the cardiac 14-3-3 interactome may be a potential therapeutic target in cardiovascular metabolic and proteostatic disease states, as it already is in cancer therapy.
14-3-3 蛋白家族已知与许多非心肌细胞类型的蛋白相互作用，调节多种信号通路，特别是与能量和蛋白质稳态相关的信号通路；14-3-3 网络是癌症和神经疾病中关键代谢和蛋白质稳态信号的治疗靶点。尽管心脏对营养和能量变化非常敏感，并且多种信号通路协同作用以维持心肌细胞稳态，但心脏 14-3-3 蛋白相互作用组的结构，以及 14-3-3 蛋白-蛋白相互作用（PPIs）在心脏中的潜在功能作用都尚未被探索。
为了建立全面的图景并描述心脏 14-3-3 PPI 的功能作用。
我们评估了小鼠心脏中 14-3-3 同工型的 RNA 表达和蛋白丰度，随后在左心室进行 14-3-3 蛋白的共免疫沉淀和质谱分析。我们鉴定了 52 种组成心脏 14-3-3 相互作用组的蛋白质。多种生物信息学分析表明，与 14-3-3 结合的蛋白质中有一半以上与线粒体有关；并且推断出的线粒体 14-3-3 网络的功能是通过与线粒体内膜蛋白相互作用来调节心脏的 ATP 产生，特别是那些在线粒体复合物 I 中的蛋白。与核糖体蛋白的结合，14-3-3 蛋白可能协调蛋白质合成和蛋白质质量控制。通过免疫荧光测定验证了 14-3-3 蛋白在线粒体和核糖体上的定位。心脏 14-3-3 PPI 的推断功能是调节心脏代谢稳态和蛋白质稳态。
因此，心脏 14-3-3 相互作用组可能是心血管代谢和蛋白质稳态疾病状态的潜在治疗靶点，就像在癌症治疗中一样。
