Literature summary for 1.3.5.1 extracted from

Moosavi, B.; Zhu, X.; Yang, W.; Yang, G.
Genetic, epigenetic and biochemical regulation of succinate dehydrogenase function (2020), Biol. Chem., 401, 319-330 .

Inhibitors

Inhibitors	Comment	Organism	Structure
additional information	direct effectors are either deactivators such as oxaloacetate or activators such as substrates, anions, reduced quinone, ATP, and reduction	Homo sapiens
oxaloacetate	the interaction between SDH and oxaloacetate renders the enzyme inactive, while the interaction between the activator and enzyme prevent such interaction with oxaloacetate	Homo sapiens

Localization

Localization	Comment	Organism	GeneOntology No.	Textmining
mitochondrion	-	Mus musculus	5739	-
mitochondrion	-	Rattus norvegicus	5739	-
mitochondrion	-	Homo sapiens	5739	-

Metals/Ions

Metals/Ions	Comment	Organism	Structure
Fe2+	within Fe-S clusters	Homo sapiens

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.
succinate + a quinone	Staphylococcus aureus	-	fumarate + a quinol	-	?
succinate + a quinone	Mus musculus	-	fumarate + a quinol	-	?
succinate + a quinone	Thermus thermophilus	-	fumarate + a quinol	-	?
succinate + a quinone	Rattus norvegicus	-	fumarate + a quinol	-	?
succinate + a quinone	Neisseria meningitidis	-	fumarate + a quinol	-	?
succinate + a quinone	Caenorhabditis elegans	-	fumarate + a quinol	-	?
succinate + a quinone	Mycobacterium tuberculosis	-	fumarate + a quinol	-	?
succinate + a quinone	Brassica sp.	-	fumarate + a quinol	-	?
succinate + a quinone	Escherichia coli	-	fumarate + a quinol	-	?
succinate + a quinone	Homo sapiens	-	fumarate + a quinol	-	?
succinate + a quinone	Saccharomyces cerevisiae	-	fumarate + a quinol	-	?

Organism

Organism	UniProt	Comment	Textmining
Brassica sp.	-	-	-
Caenorhabditis elegans	-	-	-
Escherichia coli	P0AC41 AND P07014	proteins sdhA and sdhB	-
Homo sapiens	P31040 AND P21912 AND Q99643 AND O14521	proteins SDHA, SDHB, SDHC, and SDHD	-
Mus musculus	-	-	-
Mycobacterium tuberculosis	-	-	-
Neisseria meningitidis	-	-	-
Rattus norvegicus	-	-	-
Saccharomyces cerevisiae	Q00711 AND P21801 AND P33421 AND P37298	proteins SDH1, SDH2, SDH3, and SDH4	-
Staphylococcus aureus	-	-	-
Thermus thermophilus	-	-	-

Posttranslational Modification

Posttranslational Modification	Comment	Organism
acetylation	deacetylation modification of SDHA by SIRT3 (which is reversible by acetylation) increases the activity of SDH complex in mice and human chronic myelogenous leukemia cell lines (K562). SIRT3 is a member of the sirtuin family of NADP-dependent deacetylases in mitochondria which catalyses the deacetylation of various metabolic enzymes and components of oxidative phosphorylation including SDHA subunit. In line with this, acetylating compounds, in vitro, reduced the activity of SDH. Acetylation of the hydrophilic surface of SDHA may govern entrance of the substrate into the active site of the enzyme	Mus musculus
acetylation	deacetylation modification of SDHA by SIRT3 (which is reversible by acetylation) increases the activity of SDH complex in mice and human chronic myelogenous leukemia cell lines (K562). SIRT3 is a member of the sirtuin family of NADP-dependent deacetylases in mitochondria which catalyses the deacetylation of various metabolic enzymes and components of oxidative phosphorylation including SDHA subunit. In line with this, acetylating compounds, in vitro, reduced the activity of SDH. Acetylation of the hydrophilic surface of SDHA may govern entrance of the substrate into the active site of the enzyme. Deacetylation also occurs in histones by histone deacetylases (HDACs). The inhibition of class I HDACs results in higher expression of SDH and promotion of oxidative phosphorylation in skeletal muscles and adipose tissues. Accordingly, class I HDACs cause mitochondrial dysfunction by deregulation of complex I and II (SDH) in cardiomyocyte. Chidamide, a histone deacetylase inhibitor increases SDHA expression, which might have a therapeutic value, as a tumor suppressor, in multiple myeloma patients	Homo sapiens
acetylation	the minor overlap observed between lysine propionylation and acetylation sites in 67 proteins that were both acetylated and propionylated suggests that the two acylation reactions are most likely regulated independently by distinct enzymes and are possibly involved in different functions	Thermus thermophilus
acylation	the posttranslational modification is reported to occur in SDHA subunit of Thermus thermophilus. The minor overlap observed between lysine propionylation and acetylation sites in 67 proteins that are both acetylated and propionylated suggests that the two acylation reactions are most likely regulated independently by distinct enzymes and are possibly involved in different functions	Thermus thermophilus
additional information	posttranslational modifications regulate SDH levels by 4 means: phosphorylation, deacetylation, succinylation and propionylation	Staphylococcus aureus
additional information	posttranslational modifications regulate SDH levels by 4 means: phosphorylation, deacetylation, succinylation and propionylation	Mus musculus
additional information	posttranslational modifications regulate SDH levels by 4 means: phosphorylation, deacetylation, succinylation and propionylation	Thermus thermophilus
additional information	posttranslational modifications regulate SDH levels by 4 means: phosphorylation, deacetylation, succinylation and propionylation	Rattus norvegicus
additional information	posttranslational modifications regulate SDH levels by 4 means: phosphorylation, deacetylation, succinylation and propionylation	Neisseria meningitidis
additional information	posttranslational modifications regulate SDH levels by 4 means: phosphorylation, deacetylation, succinylation and propionylation	Caenorhabditis elegans
additional information	posttranslational modifications regulate SDH levels by 4 means: phosphorylation, deacetylation, succinylation and propionylation	Mycobacterium tuberculosis
additional information	posttranslational modifications regulate SDH levels by 4 means: phosphorylation, deacetylation, succinylation and propionylation	Brassica sp.
additional information	posttranslational modifications regulate SDH levels by 4 means: phosphorylation, deacetylation, succinylation and propionylation	Escherichia coli
additional information	posttranslational modifications regulate SDH levels by 4 means: phosphorylation, deacetylation, succinylation and propionylation	Homo sapiens
additional information	posttranslational modifications regulate SDH levels by 4 means: phosphorylation, deacetylation, succinylation and propionylation	Saccharomyces cerevisiae
phosphoprotein	FGR tyrosine kinase is one of the kinases that target SDHA at positions Y535 and Y596 (of rat sequence). ROS mediates the activation of FGR tyrosine kinase which phosphorylates SDHA at Y604 and that this function of FGR is required for the adjustment of metabolism under various conditions such as nutrient restriction, hypoxia/reoxygenation, and T-cell activation. This regulation together with the function of phagosomal NADPH oxidase (a source of ROS generation) seems to be essential for the activation of anti-bacterial response in macrophages through committing complex I and II (SDH) to respiration rather than their assembly. Additional to FGR, c-Src is another mitochondrial tyrosine kinase which targets both NDUFV2 (NADH dehydrogenase [ubiquinone] flavoprotein 2) at Tyr193 of respiratory complex I and SDHA at Tyr215 of complex II. NDUFV2 phosphorylation is required for NADH dehydrogenase activity, which affects both respiration and cellular ATP content. SDHA phosphorylation, on the other hand, does not alter the enzyme activity but disconcerts electron transfer resulting in the generation of reactive oxygen species. The T98G cell line and the primary neurons expressing the mutants at the corresponding Tyr residues loose viability. These observations thus propound that the mitochondrial c-Src modulates oxidative phosphorylation by phosphorylating two respiratory components and that c-Src activity is essential for cell viability. Dephosphorylation of SDHA is exemplified by PTEN-like mitochondrial phosphatase-1 (PTPMT1), an enzyme which dephosphorylates phosphatidylglycerol phosphate (in cardiolipin biogenesis pathway) and SDHA. Inhibition of PTPMT1 leads to enhanced phosphorylation and activation of SDH and consequently lower glucose concentration. Increased SDH activity lowers glucose levels by at least two mechanisms, by inducing glucose uptake and by boosting the rate of glucose utilization. Collectively these results suggest that PTPMT1 is a major coordinator of glucose utilization by mitochondria	Rattus norvegicus
phosphoprotein	ROS mediates the activation of FGR tyrosine kinase which phosphorylates SDHA at Y604 and that this function of FGR is required for the adjustment of metabolism under various conditions such as nutrient restriction, hypoxia/reoxygenation, and T-cell activation. This regulation together with the function of phagosomal NADPH oxidase (a source of ROS generation) seems to be essential for the activation of anti-bacterial response in macrophages through committing complex I and II (SDH) to respiration rather than their assembly. Additional to FGR, c-Src is another mitochondrial tyrosine kinase which targets both NDUFV2 (NADH dehydrogenase [ubiquinone] flavoprotein 2) at Tyr193 of respiratory complex I and SDHA at Tyr215 of complex II. NDUFV2 phosphorylation is required for NADH dehydrogenase activity, which affects both respiration and cellular ATP content. SDHA phosphorylation, on the other hand, does not alter the enzyme activity but disconcerts electron transfer resulting in the generation of reactive oxygen species. The T98G cell line and the primary neurons expressing the mutants at the corresponding Tyr residues loose viability. These observations thus propound that the mitochondrial c-Src modulates oxidative phosphorylation by phosphorylating two respiratory components and that c-Src activity is essential for cell viability. Dephosphorylation of SDHA is exemplified by PTEN-like mitochondrial phosphatase-1 (PTPMT1), an enzyme which dephosphorylates phosphatidylglycerol phosphate (in cardiolipin biogenesis pathway) and SDHA. Inhibition of PTPMT1 leads to enhanced phosphorylation and activation of SDH and consequently lower glucose concentration. Increased SDH activity lowers glucose levels by at least two mechanisms, by inducing glucose uptake and by boosting the rate of glucose utilization. Collectively these results suggest that PTPMT1 is a major coordinator of glucose utilization by mitochondria	Homo sapiens
succinylation	the posttranslational modification converts the cationic lysine side chain to an anion with diverse implications for protein structure and function. Systematic profiling of the mammalian succinylome, identifies SDHA and SDHB as two succinylated proteins. Most of the succinylation sites identified across the succinylome have no overlap with acetylation sites, suggesting differential regulation of succinylation and acetylation	Homo sapiens

Source Tissue

Source Tissue	Comment	Organism	Textmining
cardiac muscle fiber	-	Homo sapiens	-
myoblast	-	Homo sapiens	-

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.
succinate + a quinone	-	Staphylococcus aureus	fumarate + a quinol	-	?
succinate + a quinone	-	Mus musculus	fumarate + a quinol	-	?
succinate + a quinone	-	Thermus thermophilus	fumarate + a quinol	-	?
succinate + a quinone	-	Rattus norvegicus	fumarate + a quinol	-	?
succinate + a quinone	-	Neisseria meningitidis	fumarate + a quinol	-	?
succinate + a quinone	-	Caenorhabditis elegans	fumarate + a quinol	-	?
succinate + a quinone	-	Mycobacterium tuberculosis	fumarate + a quinol	-	?
succinate + a quinone	-	Brassica sp.	fumarate + a quinol	-	?
succinate + a quinone	-	Escherichia coli	fumarate + a quinol	-	?
succinate + a quinone	-	Homo sapiens	fumarate + a quinol	-	?
succinate + a quinone	-	Saccharomyces cerevisiae	fumarate + a quinol	-	?

Synonyms

Synonyms	Comment	Organism
complex II	-	Staphylococcus aureus
complex II	-	Mus musculus
complex II	-	Thermus thermophilus
complex II	-	Rattus norvegicus
complex II	-	Neisseria meningitidis
complex II	-	Caenorhabditis elegans
complex II	-	Mycobacterium tuberculosis
complex II	-	Brassica sp.
complex II	-	Escherichia coli
complex II	-	Homo sapiens
complex II	-	Saccharomyces cerevisiae
SDH	-	Staphylococcus aureus
SDH	-	Mus musculus
SDH	-	Thermus thermophilus
SDH	-	Rattus norvegicus
SDH	-	Neisseria meningitidis
SDH	-	Caenorhabditis elegans
SDH	-	Mycobacterium tuberculosis
SDH	-	Brassica sp.
SDH	-	Escherichia coli
SDH	-	Homo sapiens
SDH	-	Saccharomyces cerevisiae
SDH1	-	Saccharomyces cerevisiae
SDH2	-	Saccharomyces cerevisiae
SDH3	-	Saccharomyces cerevisiae
SDH4	-	Saccharomyces cerevisiae
SdhA	-	Mus musculus
SdhA	-	Rattus norvegicus
SdhA	-	Escherichia coli
SdhA	-	Homo sapiens
SDHB	-	Mus musculus
SDHB	-	Rattus norvegicus
SDHB	-	Escherichia coli
SDHB	-	Homo sapiens
SdhC	-	Mus musculus
SdhC	-	Rattus norvegicus
SdhC	-	Homo sapiens
SdhD	-	Mus musculus
SdhD	-	Rattus norvegicus
SdhD	-	Homo sapiens
SQR	-	Staphylococcus aureus
SQR	-	Mus musculus
SQR	-	Thermus thermophilus
SQR	-	Rattus norvegicus
SQR	-	Neisseria meningitidis
SQR	-	Caenorhabditis elegans
SQR	-	Mycobacterium tuberculosis
SQR	-	Brassica sp.
SQR	-	Escherichia coli
SQR	-	Homo sapiens
SQR	-	Saccharomyces cerevisiae
succinate dehydrogenase	-	Staphylococcus aureus
succinate dehydrogenase	-	Mus musculus
succinate dehydrogenase	-	Thermus thermophilus
succinate dehydrogenase	-	Rattus norvegicus
succinate dehydrogenase	-	Neisseria meningitidis
succinate dehydrogenase	-	Caenorhabditis elegans
succinate dehydrogenase	-	Mycobacterium tuberculosis
succinate dehydrogenase	-	Brassica sp.
succinate dehydrogenase	-	Escherichia coli
succinate dehydrogenase	-	Homo sapiens
succinate dehydrogenase	-	Saccharomyces cerevisiae
succinate:quinone oxidoreductase	-	Staphylococcus aureus
succinate:quinone oxidoreductase	-	Mus musculus
succinate:quinone oxidoreductase	-	Thermus thermophilus
succinate:quinone oxidoreductase	-	Rattus norvegicus
succinate:quinone oxidoreductase	-	Neisseria meningitidis
succinate:quinone oxidoreductase	-	Caenorhabditis elegans
succinate:quinone oxidoreductase	-	Mycobacterium tuberculosis
succinate:quinone oxidoreductase	-	Brassica sp.
succinate:quinone oxidoreductase	-	Escherichia coli
succinate:quinone oxidoreductase	-	Homo sapiens
succinate:quinone oxidoreductase	-	Saccharomyces cerevisiae

Expression

Organism	Comment	Expression
Escherichia coli	fnr and arcA gene products both act to repress SDHC expression in response to oxygen. The EIICBGlc protein (the ptsG gene product) is a crucial mediator of the repression of the sdhCDAB operon in the presence of glucose. It acts via the transcription factor crp, which directly regulates expression of the sdhCDAB operon. The glucose repression of this operon occurs in a cAMP-dependent manner	down
Neisseria meningitidis	in Neisseria meningitides low iron condition leads to high expression of NrrF. The latter is an sRNA that targets sdhCDAB transcript and promotes its degradation with the assistance of Hfq chaperone. The concentration of iron is sensed by Fur which represses the genes responsible for iron uptake with the assistance of ferrous iron as a corepressor	down
Homo sapiens	low levels of NFR-1 downregulate SDHA and thereby SDH complex expression. This stabilizes HIF-1 and promotes its nuclear translocation and high expression of glucose transporters and heme oxygenase-1. Deacetylation also occurs in histones by histone deacetylases (HDACs). The inhibition of class I HDACs results in higher expression of SDH and promotion of oxidative phosphorylation in skeletal muscles and adipose tissues. Chidamide, a histone deacetylase inhibitor increases SDHA expression	down
Brassica sp.	in Brassica hexaploids transcriptions of SDH genes are activated by long non-coding RNAs possibly to stimulate energy production via TCA cycle	up
Saccharomyces cerevisiae	in yeast, glucose represses the transcription of SDH2 (SDHB homologue) by a mechanism in which the upstream promoter sequence of SDHB, containing four regulatory elements, is shown to interact with the HAP2/3/4 transcription activator complex. Maximum expression of SDH1 (SDHA homologue) and SDH3 (SDHC homologue) require the same transcription activator. Accordingly, the expression of SDH1 and SDH3 is enhanced 5 times more strongly on galactose than on glucose. Likewise, an increase in the abundance of SDH4 (SDHD homologue) mRNA observed in media containing galactose rather than glucose. Therefore it seems that the same transcription activator complex regulates the transcription of all 4 genes encoding subunits of SDH	up
Homo sapiens	the nuclear respiratory factor-1 (NRF-1) induces SDH expression through binding to the gene promoters of SDHA and SDHD in the aerobic cardiomyocyte	up

General Information

General Information	Comment	Organism
evolution	the SDH function is regulated through distinct molecular pathways in different species	Brassica sp.
evolution	the SDH function is regulated through distinct molecular pathways in different species. SDH has evolved to have extra roles in certain microorganisms and immune cells to meet the energy demands of the cells	Staphylococcus aureus
evolution	the SDH function is regulated through distinct molecular pathways in different species. SDH has evolved to have extra roles in certain microorganisms and immune cells to meet the energy demands of the cells	Mus musculus
evolution	the SDH function is regulated through distinct molecular pathways in different species. SDH has evolved to have extra roles in certain microorganisms and immune cells to meet the energy demands of the cells	Thermus thermophilus
evolution	the SDH function is regulated through distinct molecular pathways in different species. SDH has evolved to have extra roles in certain microorganisms and immune cells to meet the energy demands of the cells	Rattus norvegicus
evolution	the SDH function is regulated through distinct molecular pathways in different species. SDH has evolved to have extra roles in certain microorganisms and immune cells to meet the energy demands of the cells	Neisseria meningitidis
evolution	the SDH function is regulated through distinct molecular pathways in different species. SDH has evolved to have extra roles in certain microorganisms and immune cells to meet the energy demands of the cells	Caenorhabditis elegans
evolution	the SDH function is regulated through distinct molecular pathways in different species. SDH has evolved to have extra roles in certain microorganisms and immune cells to meet the energy demands of the cells	Mycobacterium tuberculosis
evolution	the SDH function is regulated through distinct molecular pathways in different species. SDH has evolved to have extra roles in certain microorganisms and immune cells to meet the energy demands of the cells	Escherichia coli
evolution	the SDH function is regulated through distinct molecular pathways in different species. SDH has evolved to have extra roles in certain microorganisms and immune cells to meet the energy demands of the cells	Homo sapiens
evolution	the SDH function is regulated through distinct molecular pathways in different species. SDH has evolved to have extra roles in certain microorganisms and immune cells to meet the energy demands of the cells	Saccharomyces cerevisiae
malfunction	impaired function of SDH results in deleterious disorders from cancer to neurodegeneration. Defective SDH leads to tumorigenesis, where accumulated succinate promotes HIF-1 stabilization. In humans, another regulatory mechanism through alternative splicing of SDHC transcript is reported in which a shorter isoform of SDHC (DELTA5 lacking exon 5) is produced which lacks heme binding region and therefore has no function. This results in significant downregulation of SDH complex. This variant of SDHC may, therefore, act as a dominant-negative inhibitor of full-length SDHC. DELAT5 may have a role in the pathogenesis of tumorigenesis associated with the malfunction of SDH. A posttranscriptional regulation has been described in late stages of lung cancer in which miR-210 (a microRNA) is overexpressed in normoxia. miR-210 targets SDHD and other transcripts of complex I and II such as NDUAF4 eventually leading to mitochondrial dysfunction and cell death. miR-210-dependent targeting of SDHD transcript activates HIF-1 and in agreement with earlier findings links loss-of-function SDH mutations to HIF-1 stabilization. A mutation in K547 of SDHA (which is typically desuccinylated by SIRT5) renders SDHA unable to interact with SDH5 and thereby made SDH inactive. Furthermore, SIRT5 promotes clear cell renal cell carcinoma (ccRCC) proliferation through inactivation of SDH and switching metabolism to aerobic glycolysis	Homo sapiens
metabolism	succinate dehydrogenase (SDH), complex II or succinate:quinone oxidoreductase (SQR) is a crucial enzyme involved in both tricarboxylic acid cycle and oxidative phosphorylation, the two primary metabolic pathways for generating ATP	Staphylococcus aureus
metabolism	succinate dehydrogenase (SDH), complex II or succinate:quinone oxidoreductase (SQR) is a crucial enzyme involved in both tricarboxylic acid cycle and oxidative phosphorylation, the two primary metabolic pathways for generating ATP	Mus musculus
metabolism	succinate dehydrogenase (SDH), complex II or succinate:quinone oxidoreductase (SQR) is a crucial enzyme involved in both tricarboxylic acid cycle and oxidative phosphorylation, the two primary metabolic pathways for generating ATP	Thermus thermophilus
metabolism	succinate dehydrogenase (SDH), complex II or succinate:quinone oxidoreductase (SQR) is a crucial enzyme involved in both tricarboxylic acid cycle and oxidative phosphorylation, the two primary metabolic pathways for generating ATP	Rattus norvegicus
metabolism	succinate dehydrogenase (SDH), complex II or succinate:quinone oxidoreductase (SQR) is a crucial enzyme involved in both tricarboxylic acid cycle and oxidative phosphorylation, the two primary metabolic pathways for generating ATP	Neisseria meningitidis
metabolism	succinate dehydrogenase (SDH), complex II or succinate:quinone oxidoreductase (SQR) is a crucial enzyme involved in both tricarboxylic acid cycle and oxidative phosphorylation, the two primary metabolic pathways for generating ATP	Caenorhabditis elegans
metabolism	succinate dehydrogenase (SDH), complex II or succinate:quinone oxidoreductase (SQR) is a crucial enzyme involved in both tricarboxylic acid cycle and oxidative phosphorylation, the two primary metabolic pathways for generating ATP	Mycobacterium tuberculosis
metabolism	succinate dehydrogenase (SDH), complex II or succinate:quinone oxidoreductase (SQR) is a crucial enzyme involved in both tricarboxylic acid cycle and oxidative phosphorylation, the two primary metabolic pathways for generating ATP	Brassica sp.
metabolism	succinate dehydrogenase (SDH), complex II or succinate:quinone oxidoreductase (SQR) is a crucial enzyme involved in both tricarboxylic acid cycle and oxidative phosphorylation, the two primary metabolic pathways for generating ATP	Escherichia coli
metabolism	succinate dehydrogenase (SDH), complex II or succinate:quinone oxidoreductase (SQR) is a crucial enzyme involved in both tricarboxylic acid cycle and oxidative phosphorylation, the two primary metabolic pathways for generating ATP	Homo sapiens
metabolism	succinate dehydrogenase (SDH), complex II or succinate:quinone oxidoreductase (SQR) is a crucial enzyme involved in both tricarboxylic acid cycle and oxidative phosphorylation, the two primary metabolic pathways for generating ATP	Saccharomyces cerevisiae
physiological function	succinate dehydrogenase (SDH), complex II or succinate:quinone oxidoreductase (SQR) is a crucial enzyme involved in both tricarboxylic acid cycle and oxidative phosphorylation, the two primary metabolic pathways for generating ATP. Enzyme regulation can occur via transcription factors, post-transcriptional regulators and modifiers, e.g. through phosphorylation, deacetylation, succinylation, propionylation, or direct effection, overview. In bacteria alteration of SDH expression by aerobiosis/anaerobiosis and various carbon sources is also implemented through transcriptional regulation. In this case fnr and arcA gene products both act to repress SDHC expression in response to oxygen. In Escherichia coli a EIICBGlc protein (the ptsG gene product) is identified, that is a component of the major glucose transport machinery known as phosphoenolpyruvate (PEP) phosphotransferase system (PTS), and a crucial mediator of the repression of the sdhCDAB operon in the presence of glucose. It acts via the transcription factor crp, which directly regulates expression of the sdhCDAB operon. The glucose repression of this operon occurs in a cAMP-dependent manner	Escherichia coli
physiological function	succinate dehydrogenase (SDH), complex II or succinate:quinone oxidoreductase (SQR) is a crucial enzyme involved in both tricarboxylic acid cycle and oxidative phosphorylation, the two primary metabolic pathways for generating ATP. Enzyme regulation can occur via transcription factors, posttranscriptional regulators and modifiers, e.g. through phosphorylation, deacetylation, succinylation, propionylation, or direct effection, overview. In bacteria alteration of SDH expression by aerobiosis/anaerobiosis and various carbon sources is also implemented through transcriptional regulation. In this case fnr and arcA gene products both act to repress SDHC expression in response to oxygen	Staphylococcus aureus
physiological function	succinate dehydrogenase (SDH), complex II or succinate:quinone oxidoreductase (SQR) is a crucial enzyme involved in both tricarboxylic acid cycle and oxidative phosphorylation, the two primary metabolic pathways for generating ATP. Enzyme regulation can occur via transcription factors, posttranscriptional regulators and modifiers, e.g. through phosphorylation, deacetylation, succinylation, propionylation, or direct effection, overview. In bacteria alteration of SDH expression by aerobiosis/anaerobiosis and various carbon sources is also implemented through transcriptional regulation. In this case fnr and arcA gene products both act to repress SDHC expression in response to oxygen	Mycobacterium tuberculosis
physiological function	succinate dehydrogenase (SDH), complex II or succinate:quinone oxidoreductase (SQR) is a crucial enzyme involved in both tricarboxylic acid cycle and oxidative phosphorylation, the two primary metabolic pathways for generating ATP. Enzyme regulation can occur via transcription factors, posttranscriptional regulators and modifiers, e.g. through phosphorylation, deacetylation, succinylation, propionylation, or direct effection, overview. In bacteria alteration of SDH expression by aerobiosis/anaerobiosis and various carbon sources is also implemented through transcriptional regulation. In this case fnr and arcA gene products both act to repress SDHC expression in response to oxygen. In Neisseria meningitides low iron condition leads to high expression of NrrF. The latter is an sRNA that targets sdhCDAB transcript and promotes its degradation with the assistance of Hfq chaperone. The concentration of iron is sensed by Fur which represses the genes responsible for iron uptake with the assistance of ferrous iron as a corepressor	Neisseria meningitidis
physiological function	succinate dehydrogenase (SDH), complex II or succinate:quinone oxidoreductase (SQR) is a crucial enzyme involved in both tricarboxylic acid cycle and oxidative phosphorylation, the two primary metabolic pathways for generating ATP. Enzyme regulation can occur via transcription factors, posttranscriptional regulators and modifiers, e.g. through phosphorylation, deacetylation, succinylation, propionylation, or direct effection, overview. In bacteria alteration of SDH expression by aerobiosis/anaerobiosis and various carbon sources is also implemented through transcriptional regulation. In this case, fnr and arcA gene products both act to repress SDHC expression in response to oxygen	Thermus thermophilus
physiological function	succinate dehydrogenase (SDH), complex II or succinate:quinone oxidoreductase (SQR) is a crucial enzyme involved in both tricarboxylic acid cycle and oxidative phosphorylation, the two primary metabolic pathways for generating ATP. Enzyme regulation can occur via transcription factors, posttranscriptional regulators and modifiers, e.g. through phosphorylation, deacetylation, succinylation, propionylation, or direct effection, overview. In yeast, glucose represses the transcription of SDH2 (SDHB homologue) by a mechanism in which the upstream promoter sequence of SDHB containing four regulatory elements is shown to interact with the HAP2/3/4 transcription activator complex. Maximum expression of SDH1 (SDHA homologue) and SDH3 (SDHC homologue) require the same transcription activator. Accordingly, the expression of SDH1 and SDH3 is enhanced 5 times more strongly on galactose than on glucose. Likewise, an increase in the abundance of SDH4 (SDHD homologue) mRNA observed in media containing galactose rather than glucose. Therefore it seems that the same transcription activator complex regulates the transcription of all 4 genes encoding subunits of SDH. The 5'-untranslated region (5' UTR) of the SDH2 mRNA contains a major determinant which controls its differential turnover in media containing glycerol versus glucose. Furthermore, the 5' exonuclease encoded by the XRN1 gene is necessary for the rapid degradation of the SDH1 and SDH2 mRNAs in the presence of glucose	Saccharomyces cerevisiae
physiological function	succinate dehydrogenase (SDH), complex II or succinate:quinone oxidoreductase (SQR) is a crucial enzyme involved in both tricarboxylic acid cycle and oxidative phosphorylation, the two primary metabolic pathways for generating ATP. SDH function is tailored in different cell types to meet the energy demands, SDH function is differently regulated in distinct cell types. Enzyme regulation can occur via transcription factors, post-transcriptional regulators and modifiers, e.g. through phosphorylation, deacetylation, succinylation, propionylation, or direct effection, overview. In Brassica hexaploids transcriptions of SDH genes are activated by long non-coding RNAs possibly to stimulate energy production via TCA cycle	Brassica sp.
physiological function	succinate dehydrogenase (SDH), complex II or succinate:quinone oxidoreductase (SQR) is a crucial enzyme involved in both tricarboxylic acid cycle and oxidative phosphorylation, the two primary metabolic pathways for generating ATP. SDH function is tailored in different cell types to meet the energy demands, SDH function is differently regulated in distinct cell types. Enzyme regulation can occur via transcription factors, post-transcriptional regulators and modifiers, e.g. through phosphorylation, deacetylation, succinylation, propionylation, or direct effection, overview. In human cells, the nuclear respiratory factor-1 (NRF-1) initially is the primary transcriptional regulator of mitochondrial biogenesis. NRF-1 also induces SDH expression through binding to the gene promoters of SDHA and SDHD in the aerobic cardiomyocyte. Low levels of NFR-1 downregulate SDHA and thereby SDH complex expression. This stabilizes HIF-1 and promotes its nuclear translocation and high expression of glucose transporters and heme oxygenase-1. Transcription of the genes encoding SDH subunits (particularly SDHB) of human myoblast cells requires NRF-1 and NRF-2 transcription factors. Certain levels of desuccinylase SIRT5 are required for physiological activity of SDH and any imbalance i.e. either too low or too high levels, may influence SDH activity. Direct effectors are either deactivators such as oxaloacetate or activators such as substrates, anions, reduced quinone, ATP, and reduction. The interaction between SDH and oxaloacetate renders the enzyme inactive, while the interaction between the activator and enzyme prevent such interaction with oxaloacetate	Homo sapiens
physiological function	succinate dehydrogenase (SDH), complex II or succinate:quinone oxidoreductase (SQR) is a crucial enzyme involved in both tricarboxylic acid cycle and oxidative phosphorylation, the two primary metabolic pathways for generating ATP. SDH function is tailored in different cell types to meet the energy demands, SDH function is differently regulated in distinct cell types. Enzyme regulation can occur via transcription factors, posttranscriptional regulators and modifiers, e.g. through phosphorylation, deacetylation, succinylation, propionylation, or direct effection, overview	Mus musculus
physiological function	succinate dehydrogenase (SDH), complex II or succinate:quinone oxidoreductase (SQR) is a crucial enzyme involved in both tricarboxylic acid cycle and oxidative phosphorylation, the two primary metabolic pathways for generating ATP. SDH function is tailored in different cell types to meet the energy demands, SDH function is differently regulated in distinct cell types. Enzyme regulation can occur via transcription factors, posttranscriptional regulators and modifiers, e.g. through phosphorylation, deacetylation, succinylation, propionylation, or direct effection, overview	Rattus norvegicus
physiological function	succinate dehydrogenase (SDH), complex II or succinate:quinone oxidoreductase (SQR) is a crucial enzyme involved in both tricarboxylic acid cycle and oxidative phosphorylation, the two primary metabolic pathways for generating ATP. SDH function is tailored in different cell types to meet the energy demands, SDH function is differently regulated in distinct cell types. Enzyme regulation can occur via transcription factors, posttranscriptional regulators and modifiers, e.g. through phosphorylation, deacetylation, succinylation, propionylation, or direct effection, overview	Caenorhabditis elegans