STUDIES OF PROTEINS INVOLVED IN DENTINOGENESIS

牙本质发生相关蛋白质的研究

基本信息

批准号：
7847898
负责人：
Chunlin Qin
金额：
$ 1.47万
依托单位：
TEXAS A&M UNIVERSITY HEALTH SCIENCE CTR
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-06-01 至 2010-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7847898
关键词：
Adenoviruses Affect Anabolism Animals Apatites Bacteria Biochemical Biological Biological Process Cell Culture Techniques Cell Line Cell membrane Cell surface Cells Cleaved cell Code Collaborations Complementary DNA Culture Media DSPP gene Data Defect Dental Dentin Dentin Formation Dentinogenesis Due Process Edetic Acid Enzymes Eukaryotic Cell Event Extracellular Matrix Extracellular Matrix Proteins Failure Familial hypophosphatemic bone disease Feedback Gel Gelatin Genes Growth Hydroxyapatites Immunohistochemistry Immunoprecipitation Impairment In Situ Hybridization In Vitro Incubated Kinetics Knock-out Knockout Mice Label Laboratories Laboratory culture Lead Length Mediating Messenger RNA Michigan Minerals Modeling Molecular Weight Mus Mutate Mutation New York Nodule Odontoblasts Operative Surgical Procedures Organ Culture Techniques Osteoblasts Osteoclasts Osteocytes Osteogenesis Osteoid PHEX protein Peptide Hydrolases Phenotype Physiologic pulse Play Process Property Protein Chemistry Proteins Proteoglycan Proteolysis Proteolytic Processing Radiolabeled Reaction Recombinants Reporting Role Sequence Analysis Series Siblings Site Special Hospitals Surface System Techniques Testing Time Tissues Tooth structure Transgenic Organisms Undifferentiated base bone demineralization dentin matrix protein 1 design dimyristoylphosphatidylinositol enzyme substrate falls improved in vivo inorganic phosphate insight member mineralization overexpression preference radiotracer research study

项目摘要

DESCRIPTION (provided by applicant): This proposal is based on the overall hypothesis that non-collagenous extracellular matrix (ECM) proteins play vital roles in the formation of dentin by odontoblasts and in the homeostatic mechanisms of formation and breakdown of bone by osteoblasts, osteocytes and osteoclasts. Specifically, we are focusing upon the biological functions of dentin matrix protein 1 (DMP1) and dentin sialophosphoprotein (DSPP). The importance of these two proteins in mineralized tissue formation is supported by a number of experiments showing that mice lacking genes coding for DMP1 and DSPP display defects in bone and/or dentin mineralization. It is well known that DSPP is proteolytically processed into DSP and DPP, found in the ECM of dentin. Recent data from our laboratory indicate that DPM1 is processed into 37K and 57K fragments, present in the ECM of bone and dentin. Our detailed sequence analyses show that four cleavage sites in DMP1 and two in DSPP are X-Asp bonds, strongly suggesting that these two proteins are processed by the same proteinase. We hypothesize that this proteinase is PHEX protein, that is predominantly expressed in bone and tooth and that has a strong preference for cleavage at the NH2-terminus of aspartyl residue. This idea is supported by observations that the bony and dental defects of Dmp1 and Dspp knock-out mice are similar to those of X-linked hypophosphatemic rickets caused by mutations of the PHEX gene. Based on these findings, we propose the following hypotheses: DMPI and DSPP are inactive precursors that are proteolytically processed by cleavage of selected X-Asp bonds during or after secretion. These proteolytic reactions, catalyzed by PHEX proteinase, release functional components, 37K and/or 57K fragments (in the case of DMP1), and DSP and/or DPP (from DSPP). These processing events play significant, crucial roles in the conversion of osteoid to bone and predentin to dentin. Failure to process these two proteins during PHEX deficiency gives rise to abnormal phenotypes similar to those when Dmp1 or Dspp genes are mutated or knocked out. To test these hypotheses, we propose the following Specific Aims: 1. To determine if PHEX protein is the enzyme responsible for catalyzing the proteolytic processing of DMP1 and DSPP. 2. To study the effects of 37K and 57K fragments on mineralization. 3. To study the biosynthesis and secretion of DMP1, 37K and 57K fragments.

描述（由申请人提供）：该提案基于总体假设，即非胶质细胞外基质（ECM）蛋白蛋白在牙本质细胞以及骨骼形成和骨骼的稳态机制中起着至关重要的作用。具体而言，我们专注于牙本质基质蛋白1（DMP1）和乙蛋白唾液磷蛋白（DSPP）的生物学功能。这两种蛋白质在矿化组织形成中的重要性得到了许多实验，表明缺乏编码DMP1和DSPP的基因的小鼠在骨骼和/或牙本质矿化中显示缺陷。众所周知，DSPP在牙本质的ECM中被蛋白水解处理为DSP和DPP。我们实验室的最新数据表明，DPM1被处理成37K和57K片段，存在于骨骼和牙本质的ECM中。我们的详细序列分析表明，DMP1中的四个切割位点，DSPP中的两个是X-ASP键，强烈表明这两种蛋白质是由相同的蛋白酶处理的。我们假设该蛋白酶是PHEX蛋白，主要在骨和牙齿中表达，并且在Aspartyl残基的NH2-末端具有很强的偏爱。观察到DMP1和DSPP敲除小鼠的骨缺损和牙齿缺损的观察支持了这一想法。基于这些发现，我们提出了以下假设：DMPI和DSPP是不活跃的前体，它们在分泌过程中或分泌后通过所选X-ASP键的切割来蛋白水解处理。这些蛋白水解反应是由PHEX蛋白酶催化的，释放功能成分，37K和/或57K片段（对于DMP1），DSP和/或DPP（来自DSPP）。这些加工事件在骨质转化为骨骼和牙本质为牙本质的转化中起着重要的至关重要的作用。在pHEx缺乏症中，未能处理这两种蛋白质会导致异常表型与DMP1或DSPP基因突变或撞倒时相似。为了检验这些假设，我们提出以下特定目的：1。确定PHEX蛋白是否是负责催化DMP1和DSPP的蛋白水解加工的酶。 2。研究37K和57K片段对矿化的影响。 3。研究DMP1、37K和57K片段的生物合成和分泌。