A luminal kinase regulates sarcoplasmic reticulum calcium cycling

管腔激酶调节肌浆网钙循环

• 批准号: 9258219
• 负责人: Adam J Pollak
• 金额: $ 5.71万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-03-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9258219
• 关键词: Adult; Affect; Arrhythmia; Binding; Biochemistry; Bone Development; Buffers; Calcium; Calcium Binding; Calcium-Binding Proteins; Calsequestrin; Cardiac; Cardiac Myoblasts; Cardiac Myocytes; Cardiovascular system; Cell Line; Cell Nucleus; Cell physiology; Cells; Cellular biology; Clinical; Communities; Complement; Cytosol; DNA Sequence Alteration; Data; Defect; Development; Disease; Dyes; Familial hypophosphatemic bone disease; Family; Genetic; Golgi Apparatus; Harvest; Heart; Heart Diseases; Histidine; Human; Knock-out; Knockout Mice; Label; Laboratories; Lead; Malignant Neoplasms; Metabolism; Modeling; Monitor; Mus; Muscle; Muscle Cells; Mutation; Myocardium; Organelles; Pathway interactions; Phosphoproteins; Phosphorylation; Phosphorylation Site; Phosphotransferases; Physiological; Physiological Processes; Play; Process; Property; Protein Kinase; Proteins; Rattus; Regulation; Reporting; Role; Sarcoplasmic Reticulum; Signal Transduction; Site; Spectrophotometry; Sudden Death; Testing; Tooth structure; Trees; Ventricular; Work; base; biomineralization; bone; casein kinase; cell type; comparative; experimental study; genetic regulatory protein; heart function; in vivo; interdisciplinary approach; interest; member; new therapeutic target; novel; phosphoproteomics; prevent; protein protein interaction; secretory protein; uptake

Project Summary/Abstract Protein phosphorylation by kinases is a ubiquitous cellular process and many diseases can be attributed to alterations in kinase function. Our laboratory recently discovered a kinase, Fam20C, which uniquely resides within the lumen of the secretory pathway. Its phosphorylation of secreted proteins is important for biomineralization of Ca2+ for bone and teeth formation, and mutations to Fam20C cause deadly defects to bone development and hypo-phosphatemic rickets. Recently, we showed that Fam20C is involved in several other physiological processes, including cancer development, and its myriad diverse roles are only beginning to be elucidated and appreciated. In fact, Fam20C is responsible for >90% of the secreted phosphoproteome. In our preliminary data here, we identified two Fam20C substrates, histidine-rich calcium binding protein (HRC) and calsequestrin 2 (CSQ2). They both reside within the lumen of the sarcoplasmic reticulum (SR), a secretory pathway organelle within cardiac muscle cells, which stores Ca2+ for muscle excitation-contraction. Proper heart function relies on precise Ca2+ cycling through the SR, and alterations to this process can cause heart disease, which is the world deadliest disease. A genetic mutation to HRC that causes heart disease has been previously identified. We show here that the mutation blocks Fam20C phosphorylation at that site. Furthermore, CSQ2 is also phosphorylated by Fam20C. The identity of a luminal SR kinase has been highly speculated, but never accurately reported. We hypothesize that Fam20C phosphorylation will regulate Ca2+ cycling through the SR. We will use a combination of biochemistry, cell biology, mouse genetics, and mass spectrophotometry to demonstrate this. With the development of a Fam20C specific cardiac mouse knockout, we will determine Fam20C's physiologic role in SR Ca2+ cycling. We will also use mass spectrophotometry to define the Fam20C dependent SR phosphoproteome. We anticipate that our experiments will reveal novel factors that control normal and diseased heart function, and will likely lead to new therapeutic targeting strategies.

项目摘要/摘要 蛋白被激酶磷酸化是一个普遍存在的细胞过程，许多疾病可能是 可归因于激酶功能的改变。我们实验室最近发现了一种名为Fam20C的激酶，它 唯一地驻留在分泌途径的管腔内。它对分泌蛋白的磷酸化是 钙离子对骨骼和牙齿形成的生物矿化以及Fam20C突变的重要作用 致命的骨骼发育缺陷和低血磷性软骨病。最近，我们展示了 Fam20C参与了其他几个生理过程，包括癌症的发生，以及它的 无数不同的角色才刚刚开始被阐明和欣赏。事实上，Fam20C是 负责~gt；90%的分泌型磷蛋白质组。 在我们的初步数据中，我们确定了两种FAM20C底物，富含组氨酸的钙结合 蛋白质(HRC)和钙调蛋白2(CSQ2)。它们都位于肌浆管腔内。 网状结构(SR)是心肌细胞内的一种分泌途径细胞器，为肌肉储存钙离子 兴奋收缩。正常的心脏功能依赖于在SR中精确的钙循环，以及 这一过程的改变可能会导致心脏病，这是世界上最致命的疾病。一种基因 之前已经发现了会导致心脏病的HRC基因突变。我们在这里表明， 突变会阻止该位点的Fam20C磷酸化。此外，CSQ2还被磷酸化 Fam20C。流明SR激酶的身份一直被高度推测，但从来没有准确的报道。 我们推测，Fam20C的磷酸化将通过SR调节钙循环。我们会 使用生物化学、细胞生物学、小鼠遗传学和质量分光光度法相结合的方法 展示一下这一点。随着Fam20C特异性心脏小鼠基因敲除的开发，我们将 确定Fam20C在肌质网钙循环中的生理作用。我们还将使用质量分光光度法来 定义依赖Fam20C的SR磷酸化蛋白质组。我们预计我们的实验将揭示 控制正常和疾病心脏功能的新因素，并可能导致新的治疗方法 目标策略。