2qjb
Crystal structure analysis of BMP-2 in complex with BMPR-IA variant IA/IBCrystal structure analysis of BMP-2 in complex with BMPR-IA variant IA/IB
Structural highlights
Disease[BMR1A_HUMAN] Defects in BMPR1A are a cause of juvenile polyposis syndrome (JPS) [MIM:174900]; also known as juvenile intestinal polyposis (JIP). JPS is an autosomal dominant gastrointestinal hamartomatous polyposis syndrome in which patients are at risk for developing gastrointestinal cancers. The lesions are typified by a smooth histological appearance, predominant stroma, cystic spaces and lack of a smooth muscle core. Multiple juvenile polyps usually occur in a number of Mendelian disorders. Sometimes, these polyps occur without associated features as in JPS; here, polyps tend to occur in the large bowel and are associated with an increased risk of colon and other gastrointestinal cancers.[1] [2] [3] [4] [5] Defects in BMPR1A are a cause of Cowden disease (CD) [MIM:158350]. CD is an autosomal dominant cancer syndrome characterized by multiple hamartomas and by a high risk for breast, thyroid and endometrial cancers.[6] [7] Defects in BMPR1A are the cause of hereditary mixed polyposis syndrome 2 (HMPS2) [MIM:610069]. Hereditary mixed polyposis syndrome (HMPS) is characterized by atypical juvenile polyps, colonic adenomas, and colorectal carcinomas.[8] Note=A microdeletion of chromosome 10q23 involving BMPR1A and PTEN is a cause of chromosome 10q23 deletion syndrome, which shows overlapping features of the following three disorders: Bannayan-Zonana syndrome, Cowden disease and juvenile polyposis syndrome.[9] Function[BMP2_HUMAN] Induces cartilage and bone formation. [BMR1A_HUMAN] On ligand binding, forms a receptor complex consisting of two type II and two type I transmembrane serine/threonine kinases. Type II receptors phosphorylate and activate type I receptors which autophosphorylate, then bind and activate SMAD transcriptional regulators. Receptor for BMP-2 and BMP-4. Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedBone morphogenetic proteins regulate many developmental processes during embryogenesis as well as tissue homeostasis in the adult. Signaling of bone morphogenetic proteins (BMPs) is accomplished by binding to two types of serine/threonine kinase transmembrane receptors termed type I and type II. Because a large number of ligands signal through a limited number of receptors, ligand-receptor interaction in the BMP superfamily is highly promiscuous, with a ligand binding to various receptors and a receptor binding many different BMP ligands. In this study we investigate the interaction of BMP-2 with its two high affinity type I receptors, BMP receptors IA (BMPR-IA) and BMPR-IB. Interestingly, 50% of the residues in the BMP-2 binding epitope of the BMPR-IA receptor are exchanged in BMPR-IB without a decrease in binding affinity or specificity for BMP-2. Our structural and functional analyses show that promiscuous binding of BMP-2 to both type I receptors is achieved by inherent backbone and side-chain flexibility as well as by variable hydration of the ligand-receptor interface enabling the BMP-2 surface to adapt to different receptor geometries. Despite the high degree of amino acid variability found in BMPR-IA and BMPR-IB binding equally to BMP-2, three single point missense mutations in the ectodomain of BMPR-IA cannot be tolerated. In juvenile polyposis syndrome these mutations have been shown to inactivate BMPR-IA. On the basis of our biochemical and biophysical analyses, we can show that the mutations, which are located outside the ligand binding epitope, alter the local or global fold of the receptor, thereby inactivating BMPR-IA and causing a loss of the BMP-2 tumor suppressor function in colon epithelial cells. Structure analysis of bone morphogenetic protein-2 type I receptor complexes reveals a mechanism of receptor inactivation in juvenile polyposis syndrome.,Kotzsch A, Nickel J, Seher A, Heinecke K, van Geersdaele L, Herrmann T, Sebald W, Mueller TD J Biol Chem. 2008 Feb 29;283(9):5876-87. Epub 2007 Dec 26. PMID:18160401[10] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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