Organic compounds -- part of the class 532-570 series – Organic compounds – Carbohydrates or derivatives
Reexamination Certificate
1994-06-16
2002-11-26
Ulm, John (Department: 1646)
Organic compounds -- part of the class 532-570 series
Organic compounds
Carbohydrates or derivatives
C435S069100, C435S252300, C435S320100, C536S024310
Reexamination Certificate
active
06486310
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention is generally in the area of dopamine receptors, and is specifically a gene encoding a dopamine D
4
receptor, its flanking 5′ and 3′ sequences, and its derived cDNA, and methods of use thereof in screening for compounds having selective effects on the cardiovasculature and retinal tissues through interactions with the dopamine D
4
receptor.
Dopamine is an important neurotransmitter in the central nervous system (CNS), where it is thought to be involved in a variety of functions including motor coordination, reproductive regulation, and generation of emotions. A distinct peripheral dopaminergic system is thought to exist, although it is less well characterized. CNS dopamine receptors have historically been divided into two major classes, D
1
and D
2
, which can be distinguished by pharmacological, functional, and physical characteristics (Kebabian and Calne, (1979) “Multiple receptors for dopamine”
Nature
277:93-96; Hamblin et al., (1984) “Interactions of agonists with D
2
dopamine receptors: evidence for a single receptor population existing in multiple agonist affinity-states in rat striatal membranes”
Biochem. Pharmacol.
33:877-887; Seeman et al., (1985) “Conversion of dopamine receptors from high to low affinity for dopamine”
Biochem. Pharmacol.
34:151-154; Niznik, (1987) “Dopamine receptors: molecular structure and function”
Mol. Cell. Endocrinol.
54:1-22). Peripheral dopamine receptors have been divided into DA1 and DA2 subgroups, which share some but not all pharmacological characteristics with their CNS counterparts (Goldberg and Kohli, (1987) “Identification and characterization of dopamine receptors in the cardiovascular system”
Cardiologia
32:1603-1607; Kohli et al., (1989) “Dopamine receptors in the stellate ganglion of the dog” Eur. J. Pharmacol. 164:265-272; Brodde, (1990) “Physiology and pharmacology of cardiovascular catecholamine receptors; implications for treatment of chronic heart failure”
Am. Heart J.
120:1565-1572).
Molecular cloning techniques have revealed a diversity of CNS receptor subtypes in each class. All are members of the G protein-coupled receptor gene superfamily and have seven potential transmembrane (Tm) spanning domains. In contrast to most members of the G-protein coupled receptor gene family, the D
2
-like genes have multiple exons separated by introns both in the coding and non-coding regions. Further diversity is generated by alternative splicing.
Prototypic D
2
ligand binding and signal transduction characteristics have been found for D
2
(Bunzow et al., (1988) “Cloning and expression of a rat D
2
dopamine receptor cDNA”
Nature
336:783-787) and D
3
(Sokoloff et al., (1990) “Molecular cloning and characterization of a novel dopamine receptor (D
3
) as a target for neuroleptics”
Nature
347:146-151) receptors. The recently reported human D
4
receptor also has a D
2
-like pharmacological profile (Van Tol et al., (1991) “Cloning of the gene for a human dopamine D
4
-receptor with high-affinity for the antipsychotic clozapine”
Nature
350-610-614). Two distinct D
1
receptors have also been cloned, called D
1
(Sunahara et al., (1990) “Human dopamine D
1
receptor encoded by an intronless gene on chromosome 5
” Nature
347:80-83; Zhou et al., (1990) “Cloning and expression of human and rat D
1
dopamine receptors”
Nature
347:76-80; Monsma et al., (1990) “Molecular cloning and expression of a D
1
dopamine receptor linked to adenylyl cyclase activation”
Proc. Natl. Acad. Sci. USA
87:6723-6727; Dearry et al., (1990) “Molecular cloning and expression of the gene for a human D
1
dopamine receptor”
Nature
347:72-76) and D
5
(Sunahara et al., (1991) “Cloning of the gene for a human dopamine D
5
receptor with higher affinity for dopamine than D
1
” Nature
350:614-619). To date no peripheral dopamine receptor has been cloned, although it has been suggested that there is a low level of expression of D
3
in kidney (Sokoloff et al., 1990).
Van Tol et al. (1991) reported the isolation of a human D
4
receptor with a high affinity for the neuroleptic drug clozapine. Multiple variants of this dopamine receptor were also reported by Van Tol, et al., (1992)
Nature
358, 149-154. These receptors were also the subject of PCT WO 92/10571 by State of Oregon. Although the function of these particular receptors was not identified, they are assumed to be important in binding drugs having anti-psychotic activity.
It is an object of the present invention to provide the gene, its flanking 5′ and 3′ sequences and the derived cDNA encoding another dopamine D
4
receptor present in rat cells.
It is a further object of the present invention to provide methods for expression and screening of compounds binding the new dopamine D
4
receptor.
It is another object of the present invention to provide a method for screening for compounds having cardiovascular activity and effects on retinal tissue which specifically bind to dopamine D
4
receptors.
It is still another object of the present invention to provide a means and method for modulation of the morphology of cells expressing D
4
receptors, and other dopamine receptors, by stimulation or inhibition of the receptors via exposure of the cells to specific compounds.
SUMMARY OF THE INVENTION
A gene, its 5′ and 3′ flanking sequences and the derived cDNA encoding a rat D
4
dopamine receptor that is predominantly located in the cardiovascular and retinal systems is disclosed. The gene has been expressed in transfected mammalian cells and demonstrated to preferentially bind dopamine antagonists such as clozapine.
The gene and/or cDNA is useful as a probe for related D
4
dopamine receptors. Expressed in appropriate cell lines, it is useful as an in vitro screen for drugs which specifically bind to the receptor. Drugs that specifically bind to the receptor are then screened using standard methodology in rats, mice or dogs, for the physiological effects. Antibodies to the protein are useful in immunocyto chemical studies, identification and isolation via flow sorting of D4 expressing cell types, and in blocking or modifying the effects of D4 agonists and/or antagonists.
Stimulation or inhibition of the D
4
receptor, D
2
receptor, or D
3
receptor, either in cells naturally expressing the receptor or which have been transfected with cDNAs or genes encoding anyone or more of several dopamine receptors, has been demonstrated to allow modification of the cell morphology. In one example, the number and extent of branching of neurites in cells transfected with dopamine receptors is increased significantly by exposure to compounds selectively binding to the receptors.
REFERENCES:
Benes, F.M., et al., “Quantitative Cytoarchitectural Studies of the Cerebral Cortex of Schizophrenics”, 43Arch. Gen. Psychiatry31-35 (1986).
Brodde, O., “Physiology and Pharmacology of Cardiovascular Catecholamine Receptors: Implications for Treatment of Chronic Heart Failure”. 120American Heart Journal1565-1572 (1990).
Bunzow, J.R., et al., “Cloning and Expression of a Rat D2Dopamine Receptor cDNA”, 336 Nature 783-787 (1988).
Chan, Y., et al., “The Nucleotide Sequence of a Rat 18 S Ribosomal Ribonucleic Acid Gene and a Proposal for the Secondary Structure of 18 S Ribosomal Ribonucleic Acid”, 259The Journal of Biological Chemistry224-230 (1984).
Chen, C. and H. Okayama, “High-efficiency Transformation of Mammalian Cells by Plasmid DNA”, 7Molecular and Cellular Biology2745-2752 ((1987).
Chen E.Y. and P. H. Seeburg, “Supercoil Sequencing: A Fast and Simple Method for Sequencing Plasmid DNA”, 4DNA165-170 (1985).
Choi, H.K., et al., “Immortalization of Embryonic Mesencephalic Dopaminergic Neurons by Somatic Cell Fusion”, 552Brain Research67-76 (1991).
Chomczynski, P. and N. Sacchi, “Single-step Method of RNA Isolation by Acid Guanidinium Thiocyanate-Phenol-Chloroform Extraction”, 162Analytical Biochemistry156-159 (1987).
Cohen, A.I., et al., “Photoreceptors of Mouse Retinas Possess D4Receptors Coupled to Adenylate Cyclase”, 89Proc. Natl. Ac
O'Malley Karen L.
Todd Richard D.
Holland & Knight LLP
Ulm John
Washington University
LandOfFree
Gene encoding the rat dopamine D4 receptor does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Gene encoding the rat dopamine D4 receptor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Gene encoding the rat dopamine D4 receptor will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2969923