Recombinant Cercopithecus mitis Melanocyte-stimulating hormone receptor (MC1R)
Description
Introduction to Cercopithecus mitis MC1R
The Melanocyte-stimulating hormone receptor, commonly referred to as MC1R, is a G protein-coupled receptor that plays a crucial role in regulating melanocyte proliferation, differentiation, and melanin production. In Cercopithecus mitis (Blue monkey), this receptor maintains structural homology with other primate MC1R proteins while exhibiting species-specific variations that reflect evolutionary adaptations. The recombinant form of this protein enables researchers to study its properties outside the cellular environment, offering insights into its structure-function relationships and potential applications in comparative biology and biomedical research .
MC1R is positively coupled to adenylyl cyclase and serves as a key determinant of pigmentation, skin phototype, and skin cancer risk in various species. When activated, MC1R stimulates melanogenesis and increases the ratio of strongly photoprotective eumelanins (black pigments) to poorly photoprotective pheomelanin pigments (yellowish pigments) . This regulatory function makes MC1R proteins valuable subjects for comparative studies across different primate species, including the Blue monkey (Cercopithecus mitis).
Taxonomic Context and Conservation
Cercopithecus mitis belongs to the Old World monkey family Cercopithecidae, which includes several closely related species also represented in the available research literature. The conservation of MC1R across these species provides valuable insights into the evolution of pigmentation systems in primates and the functional constraints on this important signaling protein. Comparative studies involving related species such as Cercopithecus diana (Diana monkey), Cercopithecus neglectus (De Brazza's monkey), and more distantly related primates like Leontopithecus chrysomelas (Golden-headed lion tamarin) help elucidate the evolutionary history of this receptor .
Expression Systems and Purification
While the specific expression system for Cercopithecus mitis MC1R is not explicitly detailed in the search results, similar recombinant MC1R proteins from related species are typically expressed in bacterial systems such as E. coli. For instance, recombinant MC1R proteins from Cercopithecus diana and Leontopithecus chrysomelas are produced in E. coli expression systems with N-terminal His tags to facilitate purification . By analogy, it is reasonable to infer that similar approaches may be employed for the recombinant production of Cercopithecus mitis MC1R.
The purification process typically involves affinity chromatography based on the tag incorporated into the recombinant protein. The resulting purified protein is typically characterized by techniques such as SDS-PAGE to confirm purity and Western blotting to verify identity.
Functional Characteristics of MC1R
Understanding the biological function of MC1R provides context for research applications of the recombinant Cercopithecus mitis protein. While specific functional studies of the Cercopithecus mitis MC1R are not detailed in the search results, insights can be drawn from research on homologous proteins in other species.
Signaling Pathways and Regulation
MC1R functions as a G protein-coupled receptor that activates adenylyl cyclase upon binding of melanocortin peptides, leading to increased intracellular cAMP levels. This signaling cascade triggers downstream effects on melanocyte function, including melanin synthesis and pigment production .
The regulation of MC1R signaling involves complex mechanisms including desensitization and internalization. Research on human MC1R indicates that these processes are mediated by G protein-coupled receptor kinases (GRKs), specifically GRK2 and GRK6. While GRK2 and GRK6 both contribute to desensitization, GRK6 specifically mediates receptor internalization through phosphorylation of residues in the cytosolic C-terminus of MC1R . These regulatory mechanisms are likely conserved to some degree in Cercopithecus mitis MC1R, given the evolutionary conservation of MC1R structure and function across primate species.
Role in Pigmentation and Evolutionary Significance
MC1R plays a crucial role in determining pigmentation patterns through its regulation of melanin synthesis. Activation of MC1R leads to increased production of eumelanin (black/brown pigment) relative to pheomelanin (yellow/red pigment), influencing skin and hair color . In humans, certain MC1R variants are associated with red hair and increased skin cancer risk, highlighting the receptor's significance in photoprotection and adaptation to environmental conditions.
The conservation of MC1R across primate species, including Cercopithecus mitis, reflects its fundamental importance in regulating pigmentation. Species-specific variations in MC1R sequence may contribute to the diverse pigmentation patterns observed across primates, representing adaptations to different ecological niches and selective pressures.
Research Applications of Recombinant Cercopithecus mitis MC1R
Recombinant Cercopithecus mitis MC1R offers numerous research applications in comparative biology, evolutionary studies, and potentially in biomedical research. These applications leverage the protein's structural integrity and functional properties to address diverse scientific questions.
Comparative Studies of Primate MC1R Evolution
The availability of recombinant MC1R proteins from multiple primate species, including Cercopithecus mitis, enables comparative studies of receptor structure, function, and evolution. Such studies can identify conserved features that reflect fundamental functional constraints and variable regions that may contribute to species-specific adaptations in pigmentation systems .
Sequence comparisons across species can reveal signatures of natural selection acting on different regions of the MC1R protein, providing insights into the evolutionary forces shaping pigmentation diversity in primates. The high sequence similarity observed between Cercopithecus mitis MC1R and homologs from related species suggests strong functional constraints on receptor structure, particularly in domains essential for ligand binding and signal transduction.
Functional Assays and Drug Discovery
Recombinant MC1R proteins serve as valuable tools for in vitro functional assays, including ligand binding studies, signal transduction analyses, and investigations of receptor-protein interactions. These assays can characterize the pharmacological properties of the receptor, including its responses to natural ligands and synthetic compounds.
In drug discovery contexts, recombinant MC1R proteins can be used for screening potential therapeutic compounds targeting the melanocortin system. Although the primary applications would likely involve human MC1R, comparative studies with recombinant MC1R from other primates, including Cercopithecus mitis, can provide valuable insights into receptor-ligand interactions and species-specific responses to potential therapeutics.
Product Specs
Note: We will prioritize shipping the format currently in stock. However, if you have specific format requirements, please indicate them when placing the order. We will fulfill your request accordingly.
Note: All our proteins are shipped with standard blue ice packs by default. If you require dry ice shipping, please inform us in advance, as additional fees will apply.
Generally, the shelf life of the liquid form is 6 months at -20°C/-80°C. The shelf life of the lyophilized form is 12 months at -20°C/-80°C.
Target Background
Q&A
What is the phylogenetic context of Cercopithecus mitis MC1R within primate evolution?
Cercopithecus mitis (gentle monkey) represents an important primate model with several subspecies including the recently described C. m. manyaraensis. Phylogenetic analyses based on mitochondrial DNA show that C. mitis forms three main clades, with C. m. manyaraensis clustering within the youngest clade (internal divergences between 1.01 and 0.42 Ma). Sister lineages include C. m. boutourlinii, C. m. albotorquatus, C. m. albogularis, and C. m. monoides . Understanding this evolutionary context is essential when studying MC1R function in this species, as receptor variations may reflect adaptive responses to different environmental pressures across the evolutionary history of these subspecies.
How does the protein structure of C. mitis MC1R differ from human MC1R?
While the search results don't directly compare C. mitis and human MC1R structures, research on MC1R across species suggests conservation of key functional domains with species-specific variations. MC1R belongs to the G-protein coupled receptor family with seven transmembrane domains. Species-specific differences typically occur in the N-terminal domain and intracellular loops which affect ligand binding properties and downstream signaling pathways . These structural differences can significantly impact experimental approaches when working with the recombinant protein.
What are the recommended expression systems for recombinant C. mitis MC1R production?
For optimal expression of functional recombinant C. mitis MC1R, mammalian expression systems are generally preferred to maintain proper post-translational modifications, particularly palmitoylation which has been shown to be critical for MC1R function . HEK293 or CHO cell lines are commonly used for GPCR expression. When selecting an expression system, researchers should consider:
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Need for post-translational modifications
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Required protein yield
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Downstream functional assays
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Potential interference from endogenous receptors
What genotyping protocols are most reliable for MC1R variant identification?
Based on established methodologies for MC1R genotyping, restriction fragment length polymorphism (RFLP) techniques using Taqα1 restriction enzyme have proven effective for identifying MC1R variants in multiple species . PCR conditions should include:
| Gene | Annealing temperature | Primer sequences (Forward and Reverse) |
|---|---|---|
| MC1R | 63°C | Forward: 5′ CCT CGG GCT GAC CAC CAA CCA GAC GGG GCC 3′ |
| Reverse: 5′ CCA TGG AGC CGC AGA TGA GCA CAT 3′ |
The resulting MC1R products can be visualized by electrophoresis on a 1% agarose gel, with fragments of 150 and 200 base pairs indicating specific variant patterns . For C. mitis MC1R, similar approaches can be adapted with species-specific primers designed based on the known sequence.
How can functional activity of recombinant C. mitis MC1R be reliably measured?
Functional activity of recombinant MC1R can be assessed through multiple complementary approaches:
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cAMP accumulation assays: Measure cAMP levels after stimulation with α-MSH or other MC1R agonists, as MC1R activation leads to increased cAMP via adenylyl cyclase .
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Calcium mobilization assays: Monitor intracellular calcium release upon receptor activation using fluorescent calcium indicators.
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Receptor binding assays: Quantify binding affinities of various ligands using radioligand competition assays.
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Forskolin response tests: Forskolin increases cAMP levels and has been shown to improve nucleotide excision repair (NER) function and DNA repair in MC1R studies .
Each assay should include appropriate positive and negative controls to confirm receptor functionality.
What statistical approaches are recommended for analyzing MC1R variant data across populations?
When analyzing MC1R variant data, researchers should implement:
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Hardy-Weinberg equilibrium testing to verify if variant frequencies depart from expected distributions in control populations .
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Multivariate logistic regression models that include relevant covariates such as:
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Assessment of heterogeneity using Q-statistic and I² metrics, with statistical significance typically set at p≤0.10 .
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Sensitivity analyses and meta-regression by factors such as:
For C. mitis population studies, additional considerations for geographical distribution and subspecies variation should be incorporated into statistical models.
How do MC1R variants correlate with coat color phenotypes in Cercopithecus mitis compared to other primates?
While specific data on C. mitis coat color genetics is limited in the search results, research on MC1R in other mammals provides insight into potential relationships. In horses, MC1R genotypes show clear associations with coat color, with the E allele related to black pigmentation and the e allele to red/brown pheomelanin expression . The allele frequencies in one study were 0.395 for E and 0.605 for e at MC1R .
For C. mitis, researchers should investigate whether similar genotype-phenotype relationships exist for the distinctive blue/gray coloration and white throat patch characteristic of these monkeys. Comparative analysis with other primates could reveal convergent or divergent evolutionary patterns in MC1R function.
What evolutionary pressures may have influenced MC1R variation in Cercopithecus mitis subspecies?
The distribution of C. mitis across different ecological zones in Africa suggests that MC1R variants may reflect adaptation to different UV radiation exposures and predation pressures. The clustering of C. m. manyaraensis within the youngest clade indicates recent evolutionary divergence . Researchers should examine:
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Correlation between habitat type and MC1R variants
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UV radiation levels across the geographic range
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Predator composition in different habitats
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Potential sexual selection pressures on coat color
These factors would contribute to understanding the adaptive significance of MC1R variants in C. mitis evolution.
How can recombinant C. mitis MC1R be utilized in comparative oncology research?
Given the established link between MC1R variants and skin cancer risk in humans , recombinant C. mitis MC1R offers valuable research opportunities in comparative oncology. Researchers could:
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Compare DNA repair efficiency between human and C. mitis MC1R variants following UV damage
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Investigate differences in signaling pathways activated by MC1R stimulation across primate species
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Develop in vitro models to test whether C. mitis MC1R confers different levels of protection against UV-induced DNA damage
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Explore potential interactions between MC1R and other cancer-related genes such as BRAF
These approaches could provide insight into species-specific cancer susceptibilities and potential novel preventive strategies.
What are the implications of palmitoylation status on recombinant C. mitis MC1R function?
Palmitoylation has been identified as a critical post-translational modification for MC1R function, with reduced palmitoylation associated with red hair color variants in humans . For recombinant C. mitis MC1R research:
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Investigate whether palmitoylation sites are conserved between human and C. mitis MC1R
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Examine if palmitoylation status affects receptor trafficking to the cell membrane
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Determine whether palmitoylation influences ligand binding affinity and signal transduction
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Explore if regulation of palmitoylation could modify MC1R activity as has been shown in other models where it reduced melanoma risk
Understanding these modifications is crucial for producing functionally relevant recombinant proteins.
How do receptor agonists and antagonists differentially affect recombinant C. mitis MC1R compared to human MC1R?
Differential responses to MC1R agonists and antagonists between species can provide insights into receptor evolution and species-specific signaling mechanisms. Researchers should investigate:
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Binding affinities of α-MSH and synthetic analogues to recombinant C. mitis MC1R
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Differences in downstream signaling cascade activation
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Potential species-specific antagonists that could serve as research tools
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Comparative responses to forskolin, which has been shown to increase cAMP levels and improve NER function and DNA repair in MC1R studies
These investigations would contribute to understanding primate-specific adaptations in melanocortin signaling.
What are common obstacles in achieving functional expression of recombinant C. mitis MC1R and how can they be overcome?
Common challenges in recombinant GPCR expression include:
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Low expression levels: Optimize codon usage for the host expression system and consider using fusion tags to improve expression and solubility.
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Improper folding: Include chaperone co-expression systems and optimize growth temperatures (typically lower temperatures slow protein synthesis and improve folding).
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Inadequate post-translational modifications: Ensure the expression system can perform relevant modifications, particularly palmitoylation which affects MC1R function .
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Receptor aggregation: Use stabilizing agents in buffers and consider insertion of thermostabilizing mutations identified through comparative sequence analysis.
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Endogenous receptor interference: Select cell lines with minimal endogenous melanocortin receptor expression or use knockout cell lines when evaluating receptor function.
How should researchers address sequence variations when designing primers for C. mitis MC1R amplification?
When designing primers for C. mitis MC1R amplification:
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Align MC1R sequences from multiple Cercopithecus subspecies to identify conserved regions
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Design primers in regions with high sequence conservation
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Consider using degenerate primers to account for potential polymorphisms
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Validate primers using in silico PCR to check for potential off-target amplification
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Optimize annealing temperatures empirically, starting with temperatures around 58-63°C as used in other MC1R studies
If multiple subspecies are being studied, verified primers for each subspecies may be necessary to account for sequence divergence.
