SDHB

Complex II of the respiratory chain, which is specifically involved in the oxidation of succinate, carries electrons from FADH to CoQ. The complex is composed of four nuclear-encoded subunits and is localized in the mitochondrial inner membrane. The iron-sulfur subunit is highly conserved and contains three cysteine-rich clusters which may comprise the iron-sulfur centers of the enzyme. Sporadic and familial mutations in this gene result in paragangliomas and pheochromocytoma, and support a link between mitochondrial dysfunction and tumorigenesis. [provided by RefSeq, Jul 2008]

Full Name

succinate dehydrogenase complex iron sulfur subunit B

Function

Iron-sulfur protein (IP) subunit of the succinate dehydrogenase complex (mitochondrial respiratory chain complex II), responsible for transferring electrons from succinate to ubiquinone (coenzyme Q).

Biological Process

Biological Process aerobic respirationManual Assertion Based On ExperimentIBA:GO_Central
Biological Process mitochondrial electron transport, succinate to ubiquinone1 PublicationIC:ComplexPortal
Biological Process proton motive force-driven mitochondrial ATP synthesis1 PublicationIC:ComplexPortal
Biological Process respiratory electron transport chainManual Assertion Based On ExperimentIBA:GO_Central
Biological Process succinate metabolic processIEA:Ensembl
Biological Process tricarboxylic acid cycleManual Assertion Based On ExperimentTAS:ProtInc

Cellular Location

Mitochondrion inner membrane

Involvement in disease

Pheochromocytoma (PCC):
A catecholamine-producing tumor of chromaffin tissue of the adrenal medulla or sympathetic paraganglia. The cardinal symptom, reflecting the increased secretion of epinephrine and norepinephrine, is hypertension, which may be persistent or intermittent.
Paragangliomas 4 (PGL4):
A neural crest tumor usually derived from the chromoreceptor tissue of a paraganglion. Paragangliomas can develop at various body sites, including the head, neck, thorax and abdomen. Most commonly, they are located in the head and neck region, specifically at the carotid bifurcation, the jugular foramen, the vagal nerve, and in the middle ear.
Paraganglioma and gastric stromal sarcoma (PGGSS):
Gastrointestinal stromal tumors may be sporadic or inherited in an autosomal dominant manner, alone or as a component of a syndrome associated with other tumors, such as in the context of neurofibromatosis type 1 (NF1). Patients have both gastrointestinal stromal tumors and paragangliomas. Susceptibility to the tumors was inherited in an apparently autosomal dominant manner, with incomplete penetrance.
Mitochondrial complex II deficiency, nuclear type 4 (MC2DN4):
A form of mitochondrial complex II deficiency, a disorder with heterogeneous clinical manifestations. Some patients have multisystem involvement of the brain, heart, muscle, liver, and kidneys resulting in death in infancy, whereas others have only isolated cardiac or muscle involvement with onset in adulthood and normal cognition. Clinical features include psychomotor regression in infants, poor growth with lack of speech development, severe spastic quadriplegia, dystonia, progressive leukoencephalopathy, muscle weakness, exercise intolerance, cardiomyopathy. Some patients manifest Leigh syndrome or Kearns-Sayre syndrome. MC2DN4 is a severe, autosomal recessive form characterized by early-onset progressive neurodegeneration with leukoencephalopathy.