Recombinant Bovine Short-chain dehydrogenase/reductase 3 (DHRS3)
Description
Introduction to DHRS3
DHRS3, also known as retinal short-chain dehydrogenase/reductase 1 (retSDR1), belongs to the short-chain dehydrogenase/reductase (SDR) family of enzymes . This protein family catalyzes the oxidation/reduction of various substrates, including retinoids and steroids . DHRS3 has received significant attention in developmental biology due to its essential role in regulating the levels of retinoic acid, a crucial morphogen that influences numerous developmental processes including embryonic patterning and organogenesis .
The bovine variant of DHRS3 shares significant structural and functional homology with its counterparts in other mammalian species, making it a valuable model for studying retinoid metabolism across species . As a key enzyme in vitamin A metabolism, DHRS3 contributes to the fine balance of retinoic acid levels, which is critical for normal development, as both excess and deficiency of retinoic acid can lead to developmental abnormalities .
Protein Structure and Classification
Bovine DHRS3 is classified under EC 1.1.1.300 and is recognized as a member of the SDR16C family of enzymes . The UniProt ID for bovine DHRS3 is O77769, providing a standardized reference for this protein in biological databases . Unlike many other SDR family members that prefer NADP as a cofactor, DHRS3 has a unique preference for the phosphorylated NAD cofactor, which influences its function as a reductase in intact cells .
Genetic Information
The DHRS3 gene in bovine species encodes for the DHRS3 protein. While the search results don't specify the exact chromosomal location of bovine DHRS3, comparative genomics indicates conservation across mammalian species . The protein shares structural similarities with DHRS3 proteins from other species, including humans, mice, and other mammals, indicating evolutionary conservation of this important enzyme .
Catalytic Function
DHRS3 functions primarily as a retinaldehyde reductase, catalyzing the conversion of all-trans-retinaldehyde back to retinol (vitamin A) . This reaction represents a critical regulatory step in the metabolism of vitamin A, as it controls the availability of retinaldehyde for oxidation to retinoic acid . By reducing retinaldehyde levels, DHRS3 effectively limits the production of retinoic acid, providing a mechanism to prevent excessive retinoic acid formation during embryonic development .
Enzymatic Pathway and Interactions
Within the retinoid metabolic pathway, DHRS3 acts in opposition to retinol dehydrogenase 10 (RDH10), which catalyzes the oxidation of retinol to retinaldehyde . This opposing action creates a regulatory mechanism that helps maintain appropriate levels of retinaldehyde, the precursor to retinoic acid . Recent studies have shown that DHRS3 and RDH10 can form a protein complex in which DHRS3 becomes enzymatically active, leading to increased conversion of retinaldehyde to retinol . This interaction appears to be specific to RDH10 and DHRS3, as other related enzymes do not show this mutually activating interaction .
Role in Development
Studies on DHRS3-deficient animal models have demonstrated the crucial role of this enzyme in embryonic development . Mice lacking DHRS3 show a 40% increase in retinoic acid levels and 60% and 55% decreases in retinol and retinyl esters, respectively, compared to wild-type littermates . These alterations in retinoid metabolism lead to various developmental defects, including abnormalities in cardiac outflow tract formation, skeletal development, and palatogenesis . Similar developmental defects have been observed in other model organisms with disrupted DHRS3 function, highlighting the evolutionary conservation of DHRS3's role in development .
Tissue Expression Patterns
While bovine-specific expression data is limited in the search results, studies in other species indicate that DHRS3 is expressed in multiple embryonic and adult tissues . Expression patterns are dynamically regulated during development, with specific expression in tissues where retinoic acid signaling plays important roles .
Regulation of Expression
DHRS3 expression is regulated by multiple factors, with retinoic acid itself being a key regulator . This creates a negative feedback loop where increased retinoic acid levels induce DHRS3 expression, which then reduces retinaldehyde availability for retinoic acid synthesis . This feedback mechanism is crucial for maintaining retinoic acid homeostasis during development .
In addition to retinoic acid, other factors that regulate DHRS3 expression include vitamin A status, with DHRS3 expression being sensitive to dietary changes in vitamin A levels . This nutritional regulation further contributes to the maintenance of appropriate retinoid metabolism under varying conditions .
Production Methods
Recombinant bovine DHRS3 is typically produced using bacterial (E. coli) or mammalian expression systems . The production process involves cloning the bovine DHRS3 gene or a portion of it into an appropriate expression vector, transforming the host cells, inducing protein expression, and purifying the resulting protein . The recombinant protein may be produced with various tags (such as His-tag) to facilitate purification and detection .
Basic Research Applications
Recombinant bovine DHRS3 serves as a valuable tool in basic research focused on retinoid metabolism and developmental biology . It provides a means to study the enzymatic properties of DHRS3 in controlled in vitro settings, offering insights into its catalytic mechanisms and substrate specificity . Additionally, recombinant DHRS3 can be used in protein-protein interaction studies to investigate its associations with other enzymes involved in retinoid metabolism, such as RDH10 .
Comparative Studies
The availability of recombinant DHRS3 from multiple species, including bovine, enables comparative studies to explore evolutionary conservation and species-specific differences in retinoid metabolism . These comparative analyses contribute to our understanding of the fundamental mechanisms of vitamin A metabolism across different taxonomic groups .
Drug Discovery and Development
Recombinant bovine DHRS3 can serve as a target for drug discovery efforts aimed at modulating retinoid metabolism . Given the importance of retinoic acid signaling in various biological processes, including development, immune function, and cancer, compounds that modulate DHRS3 activity could have therapeutic potential . In particular, the recent finding that DHRS3 regulates melanoma cell differentiation suggests potential applications in cancer research .
Evolutionary Conservation
Phylogenetic analyses have shown that DHRS3 represents an evolutionarily ancient enzyme, with homologs found in invertebrate chordates, non-chordate deuterostomes, and protostomes . This broad distribution suggests that the common ancestor of protostome and deuterostome animals (Urbilaterian) possessed a DHRS3-similar enzyme . The bovine DHRS3, like its counterparts in other vertebrates, shares key structural features that distinguish DHRS3 from other SDR family members .
Functional Conservation
Despite some species-specific differences, the fundamental function of DHRS3 in regulating retinoid metabolism appears to be conserved across species . Studies in various model organisms, including mice, zebrafish, and Xenopus, have consistently demonstrated the critical role of DHRS3 in preventing excessive retinoic acid formation during embryonic development .
Species-Specific Variations
While the core function of DHRS3 is conserved, species-specific variations in regulation, expression patterns, and protein-protein interactions may exist . These variations could reflect adaptations to different developmental programs or environmental conditions . Investigating these species-specific differences using recombinant proteins from various species, including bovine, can provide insights into the evolutionary adaptations of retinoid metabolism .
Product Specs
Note: We prioritize shipping the format currently in stock. However, if you have specific requirements for the format, please specify them during order placement, and we will accommodate your needs.
Note: All proteins are shipped with standard blue ice packs. If you require dry ice shipping, please inform us in advance, as additional charges will apply.
Generally, the shelf life of liquid form is 6 months at -20°C/-80°C. Lyophilized form has a shelf life of 12 months at -20°C/-80°C.
Target Background
Q&A
Basic Research Questions
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What is the primary enzymatic function of DHRS3 in retinoid metabolism?
DHRS3 functions as a retinaldehyde-specific reductase that converts retinaldehyde (retinal) back to retinol (vitamin A), effectively decreasing the rate of retinoic acid biosynthesis . This enzymatic activity is critical for maintaining proper retinoic acid levels during development, as demonstrated by studies showing that DHRS3 is essential for preventing formation of excess all-trans-retinoic acid (ATRA) during embryonic development .
Methodologically, researchers can assess DHRS3 function by measuring changes in retinol, retinaldehyde, and retinoic acid levels using HPLC analysis after experimental manipulation of DHRS3 expression. DHRS3-null embryos exhibit approximately 4-fold lower levels of retinol and retinyl esters compared to wild-type, with membrane-associated retinaldehyde reductase activities decreased by approximately 4-fold .
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What expression vectors are recommended for producing recombinant DHRS3?
For successful expression of recombinant DHRS3, several vector systems have been validated in the literature:
For constitutive expression:
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pIRES2 DsRed-Express2 vector has been successfully used for DHRS3 expression in neuroblastoma cell lines
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pCMV-Tag4a vector with C-terminal FLAG tag has been employed for detection and purification purposes
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pIRESneo vector has been utilized for untagged DHRS3 expression
For inducible expression:
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The Retro-X Tet-On Advanced System provides temporal control over DHRS3 expression, which is particularly useful as prolonged high-level expression can lead to cellular senescence and death in some cell lines
When designing expression constructs, researchers should consider:
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N-terminal 3xFLAG tags have been successfully used without compromising DHRS3 function
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PCR amplification using primers that incorporate appropriate restriction sites (such as EcoRI, SalI, or BamHI) facilitates directional cloning into expression vectors
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What phenotypes are observed when DHRS3 expression is altered in model systems?
Alteration of DHRS3 expression produces distinct developmental phenotypes that reflect its crucial role in retinoid metabolism:
DHRS3 knockout/knockdown effects:
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In mouse models, homozygous DHRS3 deletion leads to embryonic lethality, demonstrating its essential role in development
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In Xenopus, DHRS3 morphants exhibit significant reduction in head diameter
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Expression of neuroectoderm marker genes (en2, krox2, and hoxb3) is abolished or suppressed on the injected side in DHRS3 morphants
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Disruption of the brachyury expression ring at the dorsal blastopore lip and reduction in the migration distance of goosecoid is observed
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Increased concentration of all-trans-retinoic acid is measured in DHRS3 morphants
DHRS3 overexpression effects:
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In neuroblastoma cell lines, DHRS3 overexpression leads to morphological changes resembling cellular senescence, including enlargement and flattening of cells
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Accumulation of lipid droplets is observed, particularly in NH12 and SK-N-SH neuroblastoma cell lines
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Cell growth rate is suppressed in SK-N-SH and NH12 cell lines with DHRS3 induction
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Cell death occurs when DHRS3 is expressed at high levels for more than 6 days
These phenotypes provide valuable readouts for validating recombinant DHRS3 activity in experimental systems.
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Where is recombinant DHRS3 protein localized within cells?
Recombinant DHRS3 exhibits specific subcellular localization patterns that are important for its function:
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When expressed in neuroblastoma cell lines, DHRS3 is primarily localized to the plasma membrane, endoplasmic reticulum (ER), and nucleus
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In NH12 and SK-N-SH cells, DHRS3 expression leads to an accumulation of lipid droplets (LDs)
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Shortly after transfection, DHRS3 is distributed throughout the cytoplasm, but after prolonged expression (>5 days), it translocates specifically to the membrane surface of lipid droplets
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Electron microscopy confirms the presence of small vesicles containing DHRS3 in the cytoplasm, consistent with lipid droplet association
For visualizing recombinant DHRS3:
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Immunofluorescence using anti-DHRS3 antibodies (such as anti-DHRS3, 15393-1AP from ProteinTech) at 1:200 dilution has been validated
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Tagged versions with FLAG epitopes facilitate detection using commercially available anti-FLAG antibodies
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Co-staining with lipid-specific dyes such as Lipid Tox helps confirm association with lipid droplets
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How is DHRS3 expression regulated in response to retinoic acid?
DHRS3 participates in a feedback regulatory loop with retinoic acid signaling:
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DHRS3 expression is upregulated by all-trans-retinoic acid (atRA) exposure, as demonstrated in animal cap assays where exogenous atRA elevated DHRS3 expression
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In situ hybridization shows that DHRS3 expression domains are intensified and expanded, covering almost the entire neural plate after atRA treatment
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This upregulation creates a negative feedback loop: increased retinoic acid induces DHRS3 expression, which then reduces retinaldehyde availability for retinoic acid synthesis
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Similar expansion patterns are observed with other retinoic acid-responsive genes like cyp26a1
For experimental purposes, this regulatory relationship means:
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Recombinant DHRS3 expression systems may be influenced by endogenous retinoic acid levels in the host cells
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Pre-treatment with retinoic acid can be used to boost expression of recombinant DHRS3 driven by its native promoter
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Analysis of DHRS3 function should account for this feedback regulation when interpreting results
Advanced Research Questions
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What experimental approaches can measure enzymatic activity of recombinant DHRS3?
Measuring the enzymatic activity of recombinant DHRS3 requires specialized approaches that account for its unique properties:
| Assay Type | Methodology | Key Considerations | Detection Method |
|---|---|---|---|
| Direct enzyme assays | Incubation of purified recombinant DHRS3 with all-trans-retinaldehyde and NADPH cofactor | Requires protection from light; oxygen-free conditions recommended | HPLC with UV detection for retinol formation |
| Coupled enzyme systems | Co-expression of DHRS3 with RDH10 to account for their reciprocal activation | More physiologically relevant; mimics in vivo conditions | LC-MS/MS for sensitive detection of retinoid metabolites |
| Cell-based activity assays | Measurement of retinoid profiles in cells expressing recombinant DHRS3 | Accounts for cellular context but includes contribution of endogenous enzymes | HPLC or LC-MS/MS analysis of cell extracts |
| Competitive substrate assays | Measurement of DHRS3 activity in competition with ALDH1A2 for retinaldehyde | Mimics the competition occurring in vivo | Simultaneous measurement of retinol and retinoic acid formation |
Important methodological considerations:
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DHRS3 shows optimal activity when co-expressed with RDH10, as they reciprocally activate each other
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Membrane-associated fractions should be isolated for maximum activity, as DHRS3 is primarily membrane-bound
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NADPH must be supplied as the essential cofactor for the reduction reaction
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Activity is significantly reduced in DHRS3-null embryos, with membrane-associated retinaldehyde reductase activities decreased by approximately 4-fold
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How does the reciprocal relationship between DHRS3 and RDH10 impact experimental design with recombinant proteins?
The discovery that DHRS3 and RDH10 reciprocally activate each other has profound implications for experimental design:
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DHRS3 requires RDH10 for full enzymatic activity as a retinaldehyde reductase
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In turn, DHRS3 activates the retinol dehydrogenase activity of RDH10
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This mutually activating relationship allows for precise control over retinoic acid biosynthesis
Experimental recommendations based on this relationship:
| Experimental Condition | Expected Outcome | Experimental Consideration |
|---|---|---|
| DHRS3 expressed alone | Suboptimal retinaldehyde reductase activity | May underestimate true enzymatic potential |
| DHRS3 co-expressed with RDH10 | Enhanced retinaldehyde reductase activity | More accurately reflects physiological activity |
| DHRS3 knockout/knockdown | Decreased retinaldehyde reductase activity and decreased retinol dehydrogenase activity | Phenotypes reflect both direct and indirect effects |
| Reconstitution experiments | Restoration of both enzymatic activities | Requires careful titration of both proteins |
Researchers should:
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Design co-expression systems for recombinant DHRS3 and RDH10 when studying enzymatic activity
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Consider protein-protein interaction studies (co-immunoprecipitation, proximity ligation assays) to investigate the mechanism of mutual activation
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Account for the reciprocal relationship when interpreting phenotypes in knockout/knockdown models
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What are the optimal conditions for expressing recombinant DHRS3 in mammalian cell systems?
Successful expression of recombinant DHRS3 in mammalian cells requires optimization of several parameters:
| Expression System | Cell Lines | Vector | Induction/Expression Time | Special Considerations |
|---|---|---|---|---|
| Constitutive | SK-N-SH, NH12, TGW neuroblastoma | pIRES2 DsRed-Express2, pCMV-Tag4a | 3-5 days for optimal expression | Cell morphology changes observed after expression |
| Inducible | SK-N-SH, NH12 | Retro-X Tet-On Advanced | Expression begins 6h post-induction; optimal at 3-5 days | Prolonged expression (>6 days) leads to cell death |
| Transient | HEK293, COS-7 | pCMV-based vectors | 24-72h post-transfection | Higher expression but shorter duration |
Protein detection and validation methods:
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Western blotting using anti-DHRS3 antibodies (15393-1AP, ProteinTech) at 1:200 dilution
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For tagged constructs, anti-FLAG M2 antibodies effectively detect exogenous DHRS3
Important considerations:
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DHRS3 expression leads to accumulation of lipid droplets, especially in NH12 and SK-N-SH cells
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Cellular morphology changes resembling senescence (enlargement and flattening) occur following expression
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Cell migration is reduced in DHRS3-expressing cells, as demonstrated by gap-closure assays
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Co-expression with RDH10 enhances enzymatic activity and may be necessary for functional studies
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How can gene-expression analysis be used to validate recombinant DHRS3 activity?
Gene expression analysis provides valuable insights into the functional activity of recombinant DHRS3:
Research has shown that DHRS3 overexpression significantly alters the expression of numerous genes:
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In SK-N-SH cells with DHRS3 overexpression, 23 genes were more than 10-fold upregulated and 211 genes were more than 10-fold downregulated
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Key upregulated genes include ELFN1, TAC3, SMOC1, and NME1-NME2
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Significant downregulation was observed in genes involved in cell differentiation and cell adhesion, including LIF, CD44, COL3A1, COL5A1, THBS1, and THBS2
Methodological approaches for validating recombinant DHRS3 activity through gene expression analysis:
| Technique | Application | Advantages | Key Markers |
|---|---|---|---|
| RNA sequencing | Genome-wide expression profiling | Comprehensive, quantitative, discovers novel transcripts | Compare to established DHRS3 expression signatures |
| qRT-PCR | Targeted gene expression analysis | High sensitivity, good for validating specific markers | DHRS3, CYP26A1, NROB1, retinoid metabolism genes |
| Microarray | Medium-throughput gene expression | Well-established technology, cost-effective | Pattern matching with known DHRS3 response genes |
| In situ hybridization | Spatial expression analysis | Maps expression in tissues/embryos | neuroectoderm markers (en2, krox2, hoxb3) |
| Reporter assays | Functional readout of signaling | Direct measure of pathway activity | Retinoic acid response elements (RARE) reporters |
When validating recombinant DHRS3 activity:
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Compare expression profiles to established signatures from DHRS3 overexpression studies
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Focus on known retinoic acid-responsive genes as indicators of altered retinoid metabolism
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Use pathway analysis tools (GeneMANIA, IPA, Strand STS) to identify affected biological processes
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What methodological approaches can detect interactions between recombinant DHRS3 and other proteins?
Understanding DHRS3 interactions with other proteins, particularly RDH10, is crucial for comprehending its function:
| Technique | Application | Resolution | Key Considerations |
|---|---|---|---|
| Co-immunoprecipitation | Physical interaction detection | Protein complex level | Requires antibodies or epitope tags; may disrupt weak interactions |
| Proximity ligation assay | In situ protein interaction | Subcellular localization | Visualizes interactions in their native cellular context |
| FRET/BRET | Real-time interaction dynamics | Nanometer resolution | Requires fluorescent/bioluminescent tagging; can detect transient interactions |
| Split-protein complementation | Direct interaction validation | Binary readout | Good for confirming specific interactions; may stabilize transient interactions |
| Crosslinking mass spectrometry | Interaction interface mapping | Amino acid resolution | Identifies specific residues involved in interactions |
When studying DHRS3 interactions:
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The DHRS3-RDH10 interaction is of particular importance due to their reciprocal activation
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Membrane localization of DHRS3 may require specialized approaches for solubilization while preserving interactions
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Lipid droplet association may mediate certain protein-protein interactions
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Changes in protein localization after expression (such as movement to lipid droplets) should be monitored, as this may affect interaction partners
Consider that:
