Recombinant Human Succinate dehydrogenase [ubiquinone] cytochrome b small subunit, mitochondrial (SDHD)
Description
Structure and Functional Characteristics
SDHD is a 159-amino acid transmembrane protein (1–159 aa) that forms a heterodimer with SDHC to anchor the SDH complex (Complex II) to the inner mitochondrial membrane . Key structural and functional features include:
The SDHC/SDHD dimer binds ubiquinone and transfers electrons via a [3Fe-4S] iron-sulfur cluster, enabling succinate oxidation in the TCA cycle and linking the citric acid cycle to oxidative phosphorylation .
Applications in Research
Recombinant SDHD is used in diverse experimental contexts:
Genetic and Clinical Significance
SDHD mutations are strongly associated with familial paragangliomas and pheochromocytomas. Key findings include:
Founder Mutations
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p.Cys11X (c.33C>A): A common founder mutation in European populations, linked to hereditary paragangliomas .
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Haplotype Analysis: Identical mutations in unrelated families suggest a shared ancestral origin (e.g., Poland) .
Promoter Mutations in Melanoma
Recurrent promoter mutations (e.g., C523T, C544T) disrupt GABPA/B1 transcription factor binding, reducing SDHD expression and correlating with poor prognosis .
| Mutation | Effect on SDHD Expression | Clinical Association |
|---|---|---|
| C523T | Loss of GABPA binding | Melanoma progression |
| C544T | Impaired transcriptional activation | Reduced survival rates |
Recombinant Production and Purification
SDHD is produced via heterologous expression systems, with variations in methodology:
Role in Inflammation and ROS
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SDHD activity oxidizes succinate to fumarate, suppressing HIF-1α stabilization and IL-1β production in macrophages .
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Inhibition of SDHB/SDHC/SDHD increases mitochondrial ROS, promoting tumor growth, while SDHA inhibition has opposing effects .
Challenges in Cell Modeling
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Human SDHD-related paraganglioma cells are difficult to culture long-term due to mitochondrial dysfunction .
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Rodent models (e.g., RS0 cell line) require hypoxic conditions and stem cell factors for survival .
Comparative Analysis of Recombinant Variants
| Source | Expression System | Tag | Key Use Case |
|---|---|---|---|
| Abcam (ab116859) | Wheat germ | None | SDS-PAGE, ELISA |
| Creative BioMart | E. coli | N-terminal His | Structural studies |
| MyBioSource | Mammalian cells | Protein A | Antibody production |
Future Directions
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Therapeutic Targeting: Exploiting SDHD’s role in tumorigenesis for cancer therapies.
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Structural Biology: Resolving the atomic structure of SDHC/SDHD dimerization.
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Epigenetic Studies: Investigating promoter mutations beyond melanoma (e.g., other cancers).
Product Specs
Note: We prioritize shipping the format currently in stock. However, if you have specific format requirements, please indicate them during order placement. We will accommodate your request if possible.
Note: All proteins are shipped with standard blue ice packs by default. If dry ice shipping is required, please inform us in advance as additional fees will apply.
Generally, the shelf life of liquid form is 6 months at -20°C/-80°C. The shelf life of lyophilized form is 12 months at -20°C/-80°C.
Target Background
- In a study of 25 Mexican patients with carotid body tumors, 4 exhibited a heterozygous p81L SDHD (11q23) gene mutation. This occurrence is higher than the rate observed in the U.S. population and might explain the elevated incidence of this pathology in Mexico. PMID: 29681642
- Mutations in any of the five genes encoding the succinate dehydrogenase or mitochondrial complex II lead to corresponding familial syndromes characterized by the presence of pheochromocytomas and paragangliomas—REVIEW. PMID: 28924001
- A targeted familial genetic test should be considered from the age of 18 years for individuals with a mother carrying a germline SDHD mutation. An initial medical workup, including imaging, is recommended for SDHD-positive mutation carriers. PMID: 27856506
- Loss of the SDHD gene is associated with paragangliomas. PMID: 28099933
- Promoter mutations appear to be infrequent in CM, but lower SDHD expression might correlate with poorer prognostic features in CM. PMID: 28662141
- GABPA/B1 act as critical ETS transcription factors that dysregulate SDHD expression in the context of highly recurrent promoter mutations in melanoma. PMID: 28108517
- Mortality rates and survival in a Dutch cohort of SDHD variant carriers do not differ significantly from the general Dutch population. PMID: 25758995
- Melanomas harbor recurrent SDHD promoter mutations, primarily occurring as C>T alterations in UV-exposed melanomas. PMID: 26327518
- Loss of SDH activity results in metabolic alterations affecting non-essential amino acids. PMID: 26522426
- Metabolic sensors via Sirt3 optimize cellular reserve respiratory capacity by activating mitochondrial complex II, enhancing cell survival after hypoxic conditions. PMID: 26225774
- Evidence suggests that double pathogenic mutations in the succinate dehydrogenase complex subunit D (SDHD) gene are associated with the aggressive paraganglioma syndrome type 1 (PGL1) phenotype. PMID: 25819804
- It is proposed that SDHD mutation might contribute to the overexpression of miR-101 in malignant tumors, making miR-101 a potential diagnostic biomarker for differentiating malignant and benign pheochromocytoma. PMID: 25973039
- Hereditary pheochromocytoma / paraganglioma linked to SDHD gene mutations exhibits a more aggressive course, often involving both adrenal glands, a higher recurrence rate, and earlier onset of disease manifestations. PMID: 26591561
- Autosomal dominant susceptibility for Paraganglioma is influenced by imprinting, and mutations in the SDHD gene cause Paragangliomas only when the mutation is inherited from the father. PMID: 24973967
- SDHD deletions have been observed in a group of unrelated patients presenting with developmental delay and partial monosomy at chromosome 11. PMID: 25735893
- SDHD mutations are associated with protein and nuclear and mitochondrial genomic instability, leading to increased reactive oxygen species production in a yeast model. PMID: 25328978
- A recessive homozygous p.Asp92Gly SDHD mutation causes prenatal cardiomyopathy and a severe mitochondrial complex II deficiency. PMID: 26008905
- This study is the first to report hereditary paraganglioma-pheochromocytoma syndromes with both SDHD and RET mutations. PMID: 24375508
- Genotype-phenotype correlations were assessed in a large Dutch cohort of SDHD mutation carriers, evaluating potential differences in clinical phenotypes caused by specific SDHD gene mutations. PMID: 23586964
- Genome sequencing was performed simultaneously on all subunits (SDHA, SDHB, SDHC, and SDHD) in a larger series of KIT/PDGFRA wild-type GIST to determine the frequency of mutations and explore their biological roles. PMID: 23612575
- Findings demonstrate that maternal transmission of SDHD mutations can, in rare instances, contribute to tumorigenesis. PMID: 25300370
- Loss of heterozygosity was observed in over 50% of von Hippel-Lindau-associated pheochromocytomas, correlating with a significant decrease (p < 0.05) in both SDHAF2 and SDHD mRNA expression, suggesting a potential pathogenic role. PMID: 24322175
- Asymptomatic carriers of an SDHD mutation are at a significantly elevated risk for occult parasympathetic paraganglioma. PMID: 22948026
- The high prevalence of the G12S polymorphism of the SDHD gene in patients with multiple endocrine neoplasia type 2A raises questions about its potential role as a genetic modifier, but further research is needed to confirm this hypothesis. PMID: 22584711
- Ten distinct SDHD mutations were identified in paraganglioma cases. PMID: 22566194
- No mutations were found in the SDHD gene in cases of pheochromocytoma and abdominal paraganglioma in Western Sweden. PMID: 22270996
- The first kindred with a germline SDHD pathogenic mutation was described, exhibiting inherited paragangliomas and acromegaly due to a GH-producing pituitary adenoma. PMID: 22170724
- Two missense mutations at the start codon of the SDHD gene, including p.Met1Val (c.1A>G) and p.Met1Ile (c.3G>C), might be mutation hotspots in Chinese patients with familial head and neck paragangliomas. PMID: 21945342
- A unique combination of demographic, geographical, and historical factors in Trentino, Italy, has resulted in the oldest and largest SDHD founder effect characterized to date, transforming a rare disease (paraganglioma syndrome type 1) into an endemic condition. PMID: 22456618
- The data provide molecular evidence for imprinting at a boundary element flanking the SDHD locus, suggesting that epigenetic suppression of the maternal allele is the underlying mechanism for the imprinted penetrance of SDHD mutations. PMID: 21862453
- The majority of patients (83%) carried mutations in SDHD, with the p.Asp92Tyr Dutch founder mutation in SDHD alone accounting for 72% of all patients with HNPGL. PMID: 21561462
- Pheochromocytoma formation can occur after maternal transmission of SDHD. Tumor formation in SDHD mutation carriers requires the loss of the wild-type SDHD allele and maternal 11p15, leading to a predominant (though not exclusive) inheritance pattern after paternal SDHD transmission. PMID: 21937622
- A mutation linked to familial paraganglioma was identified as a deletion at the c.165_169 + 14del sequence. PMID: 21619495
- Research discovered a founder effect in Chinese head and neck paraganglioma patients carrying the SDHD c.3G>C mutation. PMID: 21792967
- An analysis of SDHD mutations was conducted in patients with pheochromocytomas and paragangliomas. PMID: 20505258
- These data describe a large SDHD deletion at the genomic sequence level, indicating that gross SDHD deletions could be a founder paraganglioma mutation in specific populations. PMID: 20111059
- Both the risk of developing paraganglioma and phaeochromocytoma, as well as the risk of associated symptoms, were investigated in 243 family members carrying the SDHD.D92Y founder mutation. PMID: 19584903
- The R22X mutation of the SDHD gene in hereditary paraganglioma completely eliminates the enzymatic activity of complex II in the mitochondrial respiratory chain and activates the hypoxia pathway. PMID: 11605159
- Alterations in the SDHD gene are implicated in the tumorigenesis of both midgut carcinoids and Merkel cell carcinomas. PMID: 12007193
- The identification of novel mutations in patients with phaeochromocytoma and/or paraganglioma was reported. PMID: 12111639
- A germline mutation in SDHD is associated with parasympathetic paraganglioma. PMID: 12114404
- Hereditary paraganglioma caused by the SDHD M1I mutation was observed in a second Chinese family, suggesting a founder effect. PMID: 12782822
- SDHD may play a role in colorectal and gastric cancers as a distinct type of tumor suppressor. PMID: 12883710
- Deletions of chromosome 11 regions, including the deletion of PGL1 and PGL2 loci, can lead to a severe phenotype, as exemplified by the development of paraganglioma. PMID: 15066320
- The presence of a germline mutation in the succinate dehydrogenase subunit D (SDHD) gene was reported. PMID: 15365827
- Germline mutations on the SDHD gene were found in patients with pheochromocytoma or functional paraganglioma. PMID: 16314641
- Pseudo-hypoxia can be observed in SDH-suppressed cells in the absence of oxidative stress and in the presence of effective antioxidant treatment. PMID: 16797480
- The prevalence of paragangliomas in carriers of D92Y mutations is at least 2.5%. PMID: 17227803
- The genes most commonly implicated, SDHD and SDHB, also predispose to phaeochromocytoma. SDHD demonstrates a complex inheritance pattern—tumors do not develop if the mutation is inherited from the mother. PMID: 17298303
- The mutation was not found in Chinese patients with sporadic pheochromocytoma/paraganglioma. PMID: 17526943
Q&A
What is the biological role of SDHD in mitochondrial function?
Succinate dehydrogenase (SDH), also known as complex II of the mitochondrial electron transport chain, plays a dual role in cellular metabolism by participating in both the citric acid cycle and oxidative phosphorylation. The SDHD subunit specifically anchors the SDH complex to the inner mitochondrial membrane and facilitates electron transfer from succinate to ubiquinone (coenzyme Q) during oxidative phosphorylation . This process is critical for ATP production and cellular energy homeostasis. Additionally, SDHD contributes to stabilizing the larger SDH complex, ensuring its structural integrity .
How is recombinant human SDHD protein produced?
Recombinant human SDHD protein is typically expressed in systems such as wheat germ extract or bacterial systems to ensure high yield and functionality. The protein spans amino acids 1–159 and retains its membrane-anchoring properties necessary for experimental applications such as SDS-PAGE, ELISA, and Western blotting . The choice of expression system is guided by the need for post-translational modifications and structural fidelity required for functional studies.
What are the implications of SDHD mutations in human diseases?
Mutations in SDHD are associated with various pathologies, including hereditary paragangliomas and pheochromocytomas. These mutations disrupt the electron transport chain, leading to succinate accumulation, which acts as an oncogenic metabolite by inhibiting prolyl hydroxylases and stabilizing hypoxia-inducible factors (HIFs) . This dysregulation contributes to tumorigenesis and has been implicated in clear cell renal cell carcinoma (ccRCC) as well .
How can SDHD activity be measured experimentally?
SDHD activity can be assessed using enzymatic assays that monitor succinate oxidation or electron transfer to ubiquinone. ELISA kits designed for succinate dehydrogenase quantification provide a sensitive method for measuring enzyme levels in various biological samples, including serum, plasma, and tissue lysates . These assays often incorporate controls to account for potential confounding factors such as sample hemolysis or freeze-thaw cycles.
What are key variables to consider when studying SDHD function?
In experimental designs involving SDHD, researchers must define independent variables such as genetic mutations or pharmacological inhibitors affecting SDH activity. Dependent variables typically include measures of electron transport efficiency, ATP production rates, or succinate accumulation . Extraneous variables like mitochondrial membrane integrity and sample preparation protocols should be controlled rigorously to ensure valid results.
How can experimental treatments be optimized for studying SDHD?
Experimental treatments may involve manipulating SDHD expression levels through genetic engineering or using inhibitors targeting specific components of the electron transport chain. For example, succinate analogs can be employed to study competitive inhibition at the active site of SDH . Treatments should be validated using dose-response curves and time-course studies to establish optimal conditions.
What methods can be used to study SDHD interactions within the electron transport chain?
Co-immunoprecipitation followed by mass spectrometry can identify protein-protein interactions involving SDHD within complex II. Additionally, cryo-electron microscopy provides structural insights into how SDHD anchors the complex to the mitochondrial membrane . These methods require careful optimization of buffer conditions and cross-linking agents to preserve native interactions.
How does succinate accumulation influence epigenetic regulation?
Succinate accumulation due to impaired SDH activity inhibits α-ketoglutarate-dependent dioxygenases involved in DNA demethylation and histone modification processes . This epigenetic modulation has been linked to oncogenesis in cancers such as ccRCC. Advanced studies often employ chromatin immunoprecipitation sequencing (ChIP-seq) or methylation-specific PCR to investigate these changes.
What are the challenges in modeling SDHD-related diseases in vitro?
Modeling diseases associated with SDHD mutations requires systems that accurately recapitulate mitochondrial dysfunction and metabolic alterations observed in vivo. Primary challenges include maintaining mitochondrial integrity during cell culture and replicating tissue-specific phenotypes . Organoid models derived from patient tissues have emerged as promising tools for addressing these limitations.
How do multifocality and metastasis correlate with specific SDH mutations?
Meta-analyses have demonstrated that multifocal tumors are significantly correlated with SDHD mutations, while distant metastases are more commonly associated with mutations in other subunits like SDHB . These findings highlight the importance of subtype-specific analyses when studying tumor progression mechanisms.
How should samples be prepared for studying recombinant human SDHD?
Sample preparation protocols vary depending on the type of biological material used (e.g., serum, plasma, tissue lysates). For instance:
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Serum samples should be clotted at room temperature before centrifugation.
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Plasma samples require anticoagulants such as EDTA or heparin during collection.
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Tissue homogenates may involve sonication steps followed by centrifugation at high speeds .
Proper storage conditions (e.g., -80°C) are critical for preserving sample integrity.
What controls are necessary for validating experimental results involving SDHD?
Controls should include untreated samples or samples expressing wild-type SDHD alongside those expressing mutant forms. Negative controls lacking key reagents (e.g., substrates or antibodies) help identify non-specific signals . Replicates across multiple experimental runs ensure reproducibility.
How can publication bias be minimized in meta-analyses involving SDHD?
Publication bias can be assessed using funnel plots and Egger's regression tests during meta-analyses . Researchers should include studies from diverse populations and settings to improve generalizability.
What statistical methods are suitable for analyzing SDHD-related data?
Common statistical techniques include regression analyses for correlating mutation types with clinical outcomes and ANOVA for comparing enzyme activity across experimental groups . Advanced methods like Bayesian inference may be employed for more nuanced interpretations.
