| Calcium-sensing receptor 2 (car2) and methods for using -> Monitor Keywords |
|
|
  Calcium-sensing receptor 2 (car2) and methods for usingUSPTO Application #: 20080064764Title: Calcium-sensing receptor 2 (car2) and methods for using Abstract: The current disclosure provide a novel human calcium sensing receptor named CaR2 and the nucleotide sequence that encodes the receptor. The disclosure further provides antibodies specific for CaR2. Also disclosed are methods of identifying modulators of the receptor and methods of using the identified modulators to treat calcium receptor mediated conditions. (end of abstract)
Agent: Lahive & Cockfield, LLP - Boston, MA, US Inventors: George Mbella Ekema, Pieter W. Faber, Benjamin Philip Faga, Gregory B. Foust, John J. Harrington, Paul David Jackson, Robert W. Mays USPTO Applicaton #: 20080064764 - Class: 514789000 (USPTO) Related Patent Categories: Drug, Bio-affecting And Body Treating Compositions, Miscellaneous (e.g., Hydrocarbons, Etc.) The Patent Description & Claims data below is from USPTO Patent Application 20080064764. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present application is a continuation of U.S. patent application Ser. No. 10/283,842, filed Oct. 29, 2002 (currently pending), which claims the benefit of priority of U.S. Provisional Patent Application No. 60/421,941, filed on Oct. 28, 2002 and which is related to U.S. patent application Ser. No. 10/283,656, filed on Oct. 29, 2002, the entire contents of each of which are incorporated by reference herein. BACKGROUND OF THE INVENTION [0002] Calcium is one of the most important regulatory molecules in the body because of its diverse intracellular and extracellular roles (bone mineralization; cofactor for adhesion molecules, clotting factors and additional proteins) (Brown, E. M., et al. (1999) Vitamin. Horm. 55, 1-71). For example, intracellular calcium, particularly the cytosolic free calcium concentration, is an important second messenger and cofactor for proteins and enzymes regulating a diverse set of key cellular processes. Intracellular calcium is utilized in the regulation of neurotransmission, motility, homornal secretion and cellular proliferation. Extracellular calcium serves as a cofactor for adhesion molecules, clotting factors, and other proteins; regulates neuronal excitability; and is an essential part of the mineral phase of bone. The skeleton provides a structural framework that protects critical bodily structures and facilitates locomotion. [0003] As a consequence of its critical roles the level of extracellular calcium (Ca.sup.++.sub.0) needs to be precisely regulated. The essential mechanism through which the metabolism of Ca.sup.++.sub.0 is maintained is regulation of dietary intake and absorption, in combination with Ca.sup.++ handling in the microenvironments of the renal tubules and the skeleton. [0004] The relatively recent identification of a calcium sensing receptor from bovine parathyroid (CaR) provided important information as to the signaling mechanism through which the body maintains Ca.sup.++ homeostasis. CaR is 1085 amino acid residues in length and is a member of the G-protein coupled receptor family. CaR is made up of three distinct domains; an amino terminal hydrophilic domain; a central core domain, containing 7 transmembrane helices; and a carboxy terminal hydrophobic domain (for a review see, Chattopadhyah, N. (2000) Int. J. Biochem. & Cell Biol. 32, 789-804). [0005] Whereas CaR function can explain most Ca.sup.++.sub.0 sensing (based on an approximate physiological Ca.sup.++ concentration of 1 mM and a CaR EC.sub.50 of 4.1 mM), this molecule does not adequately explain Ca.sup.++.sub.0-sensing in the essential kidney and bone environments where local concentrations can be as high as 40 mM. In kidney, raising peritubular but not luminal Ca.sup.++.sub.0 diminishes Ca.sup.++ reabsorption in the thick ascending limb of Henle's loop. In bone, raising Ca.sup.++ stimulates the function of bone-forming osteoblasts (Quarles, L. D. (1997) J. Bone Miner. Res. 12, 1971-1974) and inhibits bone resorption by osteoclasts (Zaidi, M., et al. (1989) Biochem. Biophys. Res. Commun. 183, 1461-1465. [0006] G-protein-coupled, seven transmembrane receptors (GPCRs or 7.TM. receptors) comprise the largest superfamily of proteins in the body (approximately 750 human members based on the analysis of the rough draft of the human genome). The diversity amongst endogenous ligands is exceptional, including biogenic amines, peptides, glycoproteins, lipids, nucleotides, ions and proteases. As a consequence, GPCRs are potential targets for intervention in many disease areas and, not surprisingly, they represent the most important target class of proteins for drug discovery to date, with over 30% of clinically marketed drugs being active at this receptor family. As these drugs exhibit their activity upon less than 10% of all known GPCRs, it can be foreseen that this family has the potential to yield many more clinically relevant targets. Identification of the expression pattern and correct activating ligand are crucial in formulating hypotheses about biological function and pharmacological relevance of novel GPCRs. [0007] GPCRs can be structurally classified into three major subfamilies that include the receptors related to the "light receptor" rhodopsin and the .beta..sub.2-adrenergic receptor (family A), the receptors related to the glucagon receptor (family B) and the receptors related to the metabotropic neurotransmitter receptors (family C). Family C comprises three subgroups of GPCRs, with Group I including the metabotropic glutamate receptors 1-8, Group II including the Calcium-sensing receptor (CaR) and a multigene family of putative pheromone, taste and odorant receptors, and Group III including GABA.sub.B receptors. Generally, these subgroups show .gtoreq.20% homology in their seven-transmembrane regions and posses extracellular ligand-binding domains (ECD) that are homologous to the bacterial periplasmic nutrient-binding proteins (PBPs). [0008] OC is a vitamin K-dependent bone calcium binding protein also called bone gla protein (BGP). OC is a unique non collagenous protein of the extra cellular matrix of bone that is synthesized by the bone forming cells, the osteoblasts. Human OC is a relatively small protein composed of 49 amino acids and having a molecular weight of 5,800 daltons. OC was first discovered in the bones of chicken and bovine. Over 20 years ago, the human OC was isolated and its amino acid sequence was determined ((1980) The Journal of Biological Chemistry, Vol 255, No. 18, pp. 8685-8691). OC inhibits hydroxyapatite formation in vitro and is modulated by the calcium regulating hormone 1,25-dihydroxyvitamin D, but until the current study, its precise physiological functions remained unknown. [0009] In view of the importance of calcium in both normal and pathological conditions, there is a ongoing need for the identification and biological characterization of additional members of the GPCR family in order to elucidate those members which are valuable drug targets, as well as prognostic and diagnostic markers for a variety of pathological processes. SUMMARY OF THE INVENTION [0010] The present invention is based, at least in part, on the identification and characterization of a novel human GPCR that structurally belongs to family C Group II. Following ectopic expression in mammalian cells, this GPCR was exposed to a wide variety of potential ligands and found to be activated by Ca.sup.++. The receptor was termed Calcium-sensing Receptor 2 (CaR2). [0011] CaR2 has been found to be expressed in environments where there are high levels of calcium. Immunohistochemical analysis has shown expression of CaR2 in bone, kidney, prostate, salivary, glands, testis, thymus, brain, trachea and thyroid. The present invention shows that OC synergistically activates CaR2. [0012] Accordingly, OC is a novel drug target for conditions associated with CaR2. Therefore, the methods disclosed herein are useful for treatment of conditions associated with the above-mentioned tissues, including, but not limited to, extracellular calcium concentration, metabolic conditions associated with CaR2 or OC, osteoporosis, sperm motility and viability, regulation of calcium flux in the kidneys, kidney stone formation, regulation of calcium flux in the prostate, promotion of osteoblast proliferation, e.g., for the production of osteoblasts for medical use, metastasis of cancers, cancers, e.g., breast, renal, prostate and bone cancers, regulation of bone mineralization, bone overgrowth modulation of bone healing, e.g, dental caries, osteoporosis, and other bone formation diseases, and detection of a subset of cells, e.g., for forensic analysis. [0013] The invention is also based, at least in part, on the discovery that CaR2 is modulated by OC(OC). OC is the most abundant non-collagenous protein of the extracellular matrix and is synthesized primarily by osteoblasts. Accordingly, CaR2 is a target for conditions associated with the formation and breakdown of the extracellular matrix, and conditions associated with aberrant expression of OC. [0014] Accordingly, in one aspect, this invention provides isolated nucleic acid molecules encoding CaR2 polypeptides or biologically active portions thereof, as well as nucleic acid fragments suitable as primers or hybridization probes for the detection of CaR2-encoding nucleic acids. [0015] In one embodiment, the invention features an isolated nucleic acid molecule that includes the nucleotide sequence set forth in SEQ ID NO:1. In another embodiment, the invention features an isolated nucleic acid molecule that encodes a polypeptide including the amino acid sequence set forth in SEQ ID NO:2. [0016] In still other embodiments, the invention features isolated nucleic acid molecules including nucleotide sequences that are substantially identical (e.g., 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical) to the nucleotide sequence set forth as SEQ ID NO:1. The invention further features isolated nucleic acid molecules including at least 50, 100, 150, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1500. 2000, 2500, 2600, 2700, 2800, or 2900 contiguous nucleotides of the nucleotide sequence set forth as SEQ ID NO:1. In another embodiment, the invention features isolated nucleic acid molecules which encode a polypeptide including an amino acid sequence that is substantially identical (e.g., 60% identical) to the amino acid sequence set forth as SEQ ID NO:2. The present invention also features nucleic acid molecules which encode allelic variants of the polypeptide having the amino acid sequence set forth as SEQ ID NO:2. In addition to isolated nucleic acid molecules encoding full-length polypeptides, the present invention also features nucleic acid molecules which encode fragments, for example, biologically active or antigenic fragments, of the full-length polypeptides of the present invention (e.g., fragments including at least 10 contiguous amino acid residues of the amino acid sequence of SEQ ID NO:2). In still other embodiments, the invention features nucleic acid molecules that are complementary to, antisense to, or hybridize under stringent conditions to the isolated nucleic acid molecules described herein. [0017] In another aspect, the invention provides vectors including the isolated nucleic acid molecules described herein (e.g., CaR2-encoding nucleic acid molecules). Such vectors can optionally include nucleotide sequences encoding heterologous polypeptides. Also featured are host cells including such vectors (e.g., host cells including vectors suitable for producing CaR2 nucleic acid molecules and polypeptides). [0018] The invention further provides nucleic acid constructs comprising the nucleic acid molecules described herein. In a preferred embodiment, the nucleic acid molecules of the invention are operatively linked to a regulatory sequence. [0019] In another aspect, the invention features isolated CaR2 polypeptides and/or biologically active or antigenic fragments thereof. Exemplary embodiments feature a polypeptide including the amino acid sequence set forth as of SEQ ID NO:2, a polypeptide including an amino acid sequence at least 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence set forth as of SEQ ID NO:2, a polypeptide encoded by a nucleic acid molecule including a nucleotide sequence at least 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96% 97%, 98%, 99%% identical to the nucleotide sequence set forth as SEQ ID NO:1. Also featured are fragments of the full-length polypeptides described herein (e.g., fragments including at least 10, 25, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 600, 700, 800, or 900 contiguous amino acid residues of the sequence set forth as of SEQ ID NO:2) as well as allelic variants of the polypeptide having the amino acid sequence set forth as SEQ ID NO:2. [0020] The CaR2 polypeptides and/or biologically active or antigenic fragments thereof, are useful, for example, as reagents or targets in assays applicable to treatment and/or diagnosis of calcium associated conditions. In one embodiment, a CaR2 polypeptide or fragment thereof, has a CaR2 activity. [0021] Accordingly, it is an object of the invention to provide methods wherein CaR2 polypeptides are useful as reagents or targets in calcium sensing receptor assays that are applicable to treatment and diagnosis of conditions related to calcium flux, or related to, CaR2. Continue reading... Full patent description for Calcium-sensing receptor 2 (car2) and methods for using Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Calcium-sensing receptor 2 (car2) and methods for using patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Calcium-sensing receptor 2 (car2) and methods for using or other areas of interest. ### Previous Patent Application: Novel hair growth compositions and methods for treating hair loss or related claims Next Patent Application: Apparatus for enhancing solubility Industry Class: Drug, bio-affecting and body treating compositions ### FreshPatents.com Support Thank you for viewing the Calcium-sensing receptor 2 (car2) and methods for using patent info. IP-related news and info Results in 1.97268 seconds Other interesting Feshpatents.com categories: Qualcomm , Schering-Plough , Schlumberger , Seagate , Siemens , Texas Instruments , |
||
