Recombinant Rat Kappa-type opioid receptor (Oprk1)
Shipped with Ice Packs 
In Stock 
Description
Functional Roles in Physiology
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Pain Perception: Mediates dynorphin-induced analgesia by reducing neurotransmitter release in spinal cord pathways .
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Neurotransmitter Regulation: Inhibits presynaptic calcium currents and enhances potassium conductance, dampening nociceptive signaling .
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Addiction Pathways: Genetic variations correlate with alcohol dependence and opioid addiction susceptibility .
Peripheral Neuronal Distribution
Single-cell RT-PCR studies in rodents revealed:
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Primary Afferents: Oprk1 is expressed in 50–60% of colon- and bladder-innervating afferents but only 7% of muscle afferents .
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Peptidergic Neurons: Co-expressed with calcitonin gene-related peptide (CGRP), substance P (Tac1), and TRPV1, marking a subset involved in inflammatory pain .
Transcriptional Profiling
Oprk1-positive peptidergic neurons show elevated expression of:
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Tac1 (substance P)
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Trpv1 (heat/capsaicin receptor)
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Gfrα3 (GDNF receptor)
This suggests specialized roles in nociception and neuroimmune interactions .
Pharmacological Assays
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Ligand Binding: Used to screen KOR agonists/antagonists (e.g., U69593) via radiolabeled diprenorphine displacement .
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cAMP Inhibition: Quantifies receptor activity by measuring forskolin-induced cAMP reduction .
Antibody Development
Polyclonal antibodies (e.g., Bioss bs-1094R) target epitopes in the C-terminal domain for immunohistochemistry and Western blotting .
Pathway Involvement
Limitations and Considerations
Product Specs
Form
Lyophilized powder
Note: We will prioritize shipping the format currently in stock. However, if you have a specific format requirement, please indicate it in your order notes. We will fulfill your request to the best of our ability.
Note: We will prioritize shipping the format currently in stock. However, if you have a specific format requirement, please indicate it in your order notes. We will fulfill your request to the best of our ability.
Lead Time
Delivery time
may vary depending on the purchasing method and location. Please consult your local distributor
for specific delivery timeframes.
Note: Our proteins are typically shipped with standard blue ice packs. If you require dry ice shipping, please notify us in advance. Additional fees will apply.
Note: Our proteins are typically shipped with standard blue ice packs. If you require dry ice shipping, please notify us in advance. Additional fees will apply.
Notes
Repeated freezing and thawing is not recommended. Store working aliquots at 4°C for up to one week.
Reconstitution
We recommend centrifuging the vial briefly prior to opening to ensure all contents settle to the bottom. Reconstitute the protein in sterile, deionized water to a concentration of 0.1-1.0 mg/mL. For long-term storage, we suggest adding 5-50% glycerol (final concentration) and aliquoting at -20°C/-80°C. Our standard glycerol concentration is 50%, which can be used as a reference point.
Shelf Life
Shelf life is influenced by multiple factors, including storage conditions, buffer composition, temperature, and the inherent stability of the protein itself.
Generally, the shelf life of liquid protein is 6 months at -20°C/-80°C. For lyophilized protein, the shelf life is 12 months at -20°C/-80°C.
Generally, the shelf life of liquid protein is 6 months at -20°C/-80°C. For lyophilized protein, the shelf life is 12 months at -20°C/-80°C.
Storage Condition
Store at -20°C/-80°C upon receipt. Aliquoting is recommended for multiple uses. Avoid repeated freeze-thaw cycles.
Tag Info
The tag type will be determined during the manufacturing process.
The tag type is decided during production. If you have a specific tag type preference, please inform us. We will prioritize the development of your requested tag.
Synonyms
Oprk1; Ror-d; Kappa-type opioid receptor; K-OR-1; KOR-1
Buffer Before Lyophilization
Tris/PBS-based buffer, 6%
Trehalose.
Datasheet
Please contact us to get it.
Expression Region
1-380
Protein Length
Full length protein
Species
Rattus norvegicus (Rat)
Target Names
Target Protein Sequence
MESPIQIFRGEPGPTCAPSACLLPNSSSWFPNWAESDSNGSVGSEDQQLEPAHISPAIPV
IITAVYSVVFVVGLVGNSLVMFVIIRYTKMKTATNIYIFNLALADALVTTTMPFQSAVYL
MNSWPFGDVLCKIVISIDYYNMFTSIFTLTMMSVDRYIAVCHPVKALDFRTPLKAKIINI
CIWLLASSVGISAIVLGGTKVREDVDVIECSLQFPDDEYSWWDLFMKICVFVFAFVIPVL
IIIVCYTLMILRLKSVRLLSGSREKDRNLRRITKLVLVVVAVFIICWTPIHIFILVEALG
STSHSTAVLSSYYFCIALGYTNSSLNPVLYAFLDENFKRCFRDFCFPIKMRMERQSTNRV
RNTVQDPASMRDVGGMNKPV
Uniprot No.
Target Background
Function
The kappa-type opioid receptor (Oprk1) is a G-protein coupled receptor that functions as a receptor for endogenous alpha-neoendorphins and dynorphins, but exhibits low affinity for beta-endorphins. It also serves as a receptor for various synthetic opioids and the psychoactive diterpene salvinorin A. Ligand binding triggers a conformational change, initiating signaling via guanine nucleotide-binding proteins (G proteins) and modulating the activity of downstream effectors, including adenylate cyclase. This signaling cascade leads to the inhibition of adenylate cyclase activity. Oprk1 also inhibits neurotransmitter release by reducing calcium ion currents and increasing potassium ion conductance. It plays a significant role in pain perception and mediates reduced physical activity in response to synthetic opioid treatment. Additionally, it contributes to the regulation of salivation upon exposure to synthetic opioids. Oprk1 may also play a role in arousal and the regulation of autonomic and neuroendocrine functions.
Gene References Into Functions
- Pre- and postsynaptic colocalization of the kappa opioid receptor and D2R suggests a role for the kappa opioid receptor in potentiating both the D2R inhibitory autoreceptor function and the inhibitory action of D2R on efferent medium spiny neurons. Kappa opioid receptor co-activation accelerates D2R sensitization by contributing to a decrease in dopamine release in the nucleus accumbens. PMID: 28531297
- Utilizing selective agonists and antagonists, it was demonstrated that kappa-opioid receptor stimulation normalizes endothelial ultrastructure and function in hyperlipidemic conditions. The mechanism involves preserving eNOS phosphorylation through activation of the PI3K/Akt signaling pathway and downregulation of iNOS expression/activity. PMID: 27226238
- These findings indicate that kappa opioid receptors may exhibit heightened responsiveness following social isolation, potentially leading to hypodopaminergia and contributing to an increased drive to consume ethanol. PMID: 26860203
- Hypertension was found to increase the expression of Kappa Opioid receptors and heterodimerization of apelin receptors and Kappa Opioid receptors, while reducing pERK1/2 in the left ventricle. PMID: 28987634
- Triazole 1.1 retained the antinociceptive and antipruritic efficacies of a conventional KOR agonist, but it did not induce sedation or reductions in dopamine release in mice. Moreover, it did not produce dysphoria as determined by intracranial self-stimulation. PMID: 27899527
- This study presents compelling evidence for a novel and unique neuromodulatory role for Kappa opioid receptors. PMID: 28163104
- It is suggested that mixed cardiac ion channel blockade may mediate the antiarrhythmic actions of the kappa-opioid receptor antagonist PD117,302. PMID: 26086860
- In conclusion, kappa-opioid receptors in the IL modulate pressor and tachycardiac responses caused by RS, suggesting a facilitatory role of this structure in this aversive situation. PMID: 25641629
- A brief stressor produces changes in the reward circuitry lasting several days. Our findings reveal roles for glucocorticoid receptors and kappaORs as mediators of the lasting effects of stress on synaptic plasticity. PMID: 24957331
- This study demonstrates that Oprk1 and Melanin-concentrating hormone colocalize in neurons in the lateral hypothalamus (LH) and zona incerta (ZI), while MCHR1 mRNA is widely expressed throughout the brain. PMID: 24978951
- These results, along with those reported previously, suggest that morphine dependence may be associated with regionally specific changes in kappa-opioid receptor expression in the mesocorticolimbic system. PMID: 24219160
- Kappa opioid receptor expression is reduced in stressed subjects but does not contribute to age differences in ethanol-induced conditioned taste aversion. PMID: 23276674
- The present study demonstrates the importance of k-ORs in the attenuation of pulmonary artery hypertension during hypoxia. PMID: 23838631
- Negative affective states induced by alcohol withdrawal are partially mediated by kappa-opioid receptors. PMID: 23212453
- Systemic activation of mu-receptors, but not delta- or kappa-receptors, is capable of switching rapid- to shallow-breathing rats into a long-lasting apneic state. PMID: 22796630
- Kappa-opioid receptors influence the stretch-induced electrophysiological changes and play an antiarrhythmic role in cardiac arrhythmia following myocardial infarction. PMID: 22735633
- The kappa opioid receptor system is involved in regulating stress-related behaviors associated with ethanol. PMID: 22487769
- Activation of peripheral KORs directly blocks inflammatory hyperalgesia through stimulation of the nNOS/NO signaling pathway, which is likely stimulated by PI3Kgamma/AKT signaling. PMID: 22316281
- Data suggest that DOR-KOR heteromers exist in rat primary sensory neurons and that KOR antagonists can act as modulators of DOR agonist responses, most likely through allosteric interactions between the protomers of the DOR-KOR heteromer. PMID: 22072818
- Dysregulation of kappa-opioid receptor systems contributes to the excessive self-administration observed in alcohol-dependent animals. PMID: 21338616
- The results of this study suggested that recovery from immobilization stress may alter striatal oprk1 mRNA in male rats. PMID: 21723305
- Findings suggest that fear conditioning and extinction dynamically regulate KOR expression in the BLA. PMID: 21531393
- Reduction of kappa-opioid receptor (KOR)/ mu-opioid receptor (MOR) by estrogen receptor blockade or spinal aromatase inhibition shifts spinal morphine antinociception from KOR dependent to KOR independent. PMID: 21849544
- This research provides evidence for mRNA transport and regulation of presynaptic protein synthesis of nonstructural proteins like KOR in primary sensory neurons. PMID: 17167054
- The kappa-opioid receptor system does not function in an adult-like manner during the late preweanling period. A potential explanation is that the coupling between kappa-opioid receptors and their second messengers is not fully mature by PD 17. PMID: 20435099
- The nucleus accumbens and piriform cortex are identified as brain regions in which modifications in KOR function may differentiate the Wistar Kyoto strain from Sprague Dawley rats. PMID: 19924112
- Phosphorylation of serine 369 mediates KOR desensitization and internalization. PMID: 12815037
- Long-term effects on brain opioid receptor(kappa) following short periods of maternal separation in rats. PMID: 12842289
- Immunoblotting analysis of kappa-opioid receptors from butorphanol-withdrawal rats showed significant increases in 11 of 21 brain regions examined. PMID: 14580956
- Both negative and positive functional interactions between delta, mu, and kappa opioid receptors regulate the influence of MET on H(2)O(2) and NO production in rat peritoneal macrophages. PMID: 15467355
- Oprk1 is expressed in the cerebellar cortex. PMID: 15778854
- Our results point to an involvement of KOR and nNOS in the same intracellular network that controls the development of morphine tolerance and dependence. PMID: 15950775
- Regional changes in the mRNA for and protein levels of the kappa-opioid receptor highlight highly specialized roles for this receptor in the development of physical dependence on and the expression of withdrawal from butorphanol dependence. PMID: 16130146
- Endogenous opioids modulate the pressor response to intracerebral AngII; this effect is primarily mediated through endogenous Oprk1 agonists rather than Oprm1; alteration of baroreceptor sensitivity by angII is modulated by endogenous kappa opioids. PMID: 17980907
- Kappa-ORs offer cardioprotection primarily when activated prior to, not after, reperfusion. PMID: 18500486
- These data contribute to the growing body of literature demonstrating that kappa opioid receptors can modulate diverse afferent signaling to the locus caeruleus. PMID: 19009591
- The present study provides evidence that the antidipsogenic effect observed in rats following third ventricle injections of IL-1beta depends on the functional integrity of a brain kappa-opioid-dependent component. PMID: 19217659
- This study provides evidence for the first time of the precise location of kappa-ORs in PAs and PASMCs of rats and that hypoxia upregulates expression of kappa-ORs. PMID: 19462402
- The kappa-opioid receptor in the anteroventral preoptic region is crucial for the reduction of body temperature during hypoxia. PMID: 19545549
- Findings suggest that antinociception induced by activation of kappa opioid receptors in the TMJ region is mediated by the L-arginine/NO/cGMP pathway in both sexes. PMID: 19567249
Database Links
Protein Families
G-protein coupled receptor 1 family
Subcellular Location
Cell membrane; Multi-pass membrane protein.
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