Biology:SDHAF2
 Generic protein structure example |
Succinate dehydrogenase complex assembly factor 2, formerly known as SDH5 and also known as SDH assembly factor 2 or SDHAF2 is a protein that in humans is encoded by the SDHAF2 gene. This gene encodes a mitochondrial protein needed for the flavination of a succinate dehydrogenase complex subunit required for activity of the complex. Mutations in this gene are associated with pheochromocytoma and paraganglioma.[1]
Structure
SDHAF2 is located on the q arm of Chromosome 11 in position 12.2 and spans 16,642 base pairs.[1] The SDHAF2 gene produces a 6.7 kDa protein composed of 65 amino acids.[2][3] This highly conserved protein is a cofactor of flavin adenine dinucleotide (FAD).[4] The structure represents a five-helix bundle with a region of well-defined conserved surface residues. This conserved region includes a negatively charged periphery and a positively charged surface, and a patch that is hydrophobic. The region is located in α-helices I, II, and the connecting band.[5]
Function
The SDHAF2 gene encodes a mitochondrial protein associated with the succinate dehydrogenase (SDH) complex (mitochondrial complex II) in the mitochondrial respiratory chain, which plays essential roles in both the electron transport chain and the Krebs(tricarboxylic acid) cycle. SDHAF2 is integral in the proper function of the SDH complex, mainly in SDH-dependent respiration, and interacts with the catalytic subunit of the complex. SDHAF2 participates in the flavination of SDH1(SDHA), another subunit of the SDH complex. It does so by incorporating the flavin adenine dinucleotide (FAD) cofactor into SDHA. Such flavination is required for a fully functional SDH complex. Knockdown of SDHAF2 leads to the loss-of-function of the SDH complex, a decrease in the enzyme complex stability, and a substantial reduction in all subunits. SDHAF2 was also found to function as a tumor suppressor.[6][7][8][9]
Clinical significance
SDHAF2 is a tumor suppressor gene. Constitutional mutations in this gene cause hereditary paraganglioma, a neuroendocrine tumor formerly known to be linked to SDH subunit mutations. paraganglioma is a neural crest tumor usually derived from the chemoreceptor tissue of a paraganglion, and may 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 vagus nerve, and in the middle ear.[10] Phenotypes include excessive catecholamine induced hypertension, dysfunction of major blood vessels and cranial nerves, significant morbidity, sweating, and palpitations. In cases of extra-adrenal localization, the tumor may turn metastatic and aggressive. Loss of SDH complex function has been known to be responsible for paraganglioma.[8][7][6] Mutations in this gene are found in the DNA of only a small fraction of patients with the disease.[7]
Interactions
SDHAF2 interacts with SDHA within the SDH catalytic dimer. In addition to SDHA, SDHAF2 has 17 protein-protein interactions, including interactions with proteins such as IMMT, SUCLG2, UBINEDDSUMO1, SSX2IP, and others.[11]
References
- ↑ 1.0 1.1 "Entrez Gene: Succinate dehydrogenase complex assembly factor 2". https://www.ncbi.nlm.nih.gov/gene/54949.
- ↑ "Integration of cardiac proteome biology and medicine by a specialized knowledgebase". Circulation Research 113 (9): 1043–53. October 2013. doi:10.1161/CIRCRESAHA.113.301151. PMID 23965338.
- ↑ Yao, Daniel. "Cardiac Organellar Protein Atlas Knowledgebase (COPaKB) —— Protein Information". https://amino.heartproteome.org/web/protein/F5H4T4.
- ↑ "Expression and somatic mutations of SDHAF2 (SDH5), a novel endocrine tumor suppressor gene in parathyroid tumors of primary hyperparathyroidism". Endocrine 38 (3): 397–401. December 2010. doi:10.1007/s12020-010-9399-0. PMID 20972721.
- ↑ "Solution NMR structure of yeast succinate dehydrogenase flavinylation factor Sdh5 reveals a putative Sdh1 binding site". Biochemistry 51 (43): 8475–7. October 2012. doi:10.1021/bi301171u. PMID 23062074.
- ↑ 6.0 6.1 "SDH5, a gene required for flavination of succinate dehydrogenase, is mutated in paraganglioma". Science 325 (5944): 1139–42. August 2009. doi:10.1126/science.1175689. PMID 19628817. Bibcode: 2009Sci...325.1139H.
- ↑ 7.0 7.1 7.2 "SDHAF2 mutations in familial and sporadic paraganglioma and phaeochromocytoma". The Lancet. Oncology 11 (4): 366–72. April 2010. doi:10.1016/S1470-2045(10)70007-3. PMID 20071235.
- ↑ 8.0 8.1 "Role of SDHAF2 and SDHD in von Hippel-Lindau associated pheochromocytomas". World Journal of Surgery 38 (3): 724–32. March 2014. doi:10.1007/s00268-013-2373-2. PMID 24322175. http://liu.diva-portal.org/smash/get/diva2:714189/FULLTEXT01.
- ↑ Hereditary Paraganglioma-Pheochromocytoma Syndromes. 1993. PMID 20301715.
- ↑ "SDHAF2 - Succinate dehydrogenase assembly factor 2, mitochondrial" (in en). https://www.uniprot.org/uniprot/Q5TEU4.
- ↑ "IntAct--open source resource for molecular interaction data". Nucleic Acids Research 35 (Database issue): D561-5. January 2007. doi:10.1093/nar/gkl958. PMID 17145710.
Further reading
- "Fine mapping of an imprinted gene for familial nonchromaffin paragangliomas, on chromosome 11q23". American Journal of Human Genetics 60 (1): 121–32. January 1997. PMID 8981955.
- "Isocitrate dehydrogenase mutations are rare in pheochromocytomas and paragangliomas". The Journal of Clinical Endocrinology and Metabolism 95 (3): 1274–8. March 2010. doi:10.1210/jc.2009-2170. PMID 19915015.
- "Fine mapping of a putatively imprinted gene for familial non-chromaffin paragangliomas to chromosome 11q13.1: evidence for genetic heterogeneity". Human Genetics 95 (1): 56–62. January 1995. doi:10.1007/bf00225075. PMID 7814027.
- "SDHAF2 (PGL2-SDH5) and hereditary head and neck paraganglioma". Clinical Cancer Research 17 (2): 247–54. January 2011. doi:10.1158/1078-0432.CCR-10-0420. PMID 21224366.
This article incorporates text from the United States National Library of Medicine, which is in the public domain.
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