title: SDHB-Deficient Cancers: The Role of Mutations That  Impair Iron Sulfur Cluster Delivery.
abstract: BACKGROUND
  Mutations in the Fe-S cluster-containing SDHB subunit of succinate dehydrogenase cause familial cancer syndromes. Recently the tripeptide motif L(I)YR was identified in the Fe-S recipient protein SDHB, to which the cochaperone HSC20 binds.
  
  
  METHODS
  In order to characterize the metabolic basis of SDH-deficient cancers we performed stable isotope-resolved metabolomics in a novel SDHB-deficient renal cell carcinoma cell line and conducted bioinformatics and biochemical screening to analyze Fe-S cluster acquisition and assembly of SDH in the presence of other cancer-causing SDHB mutations.
  
  
  RESULTS
  We found that the SDHBR46Q mutation in UOK269 cells disrupted binding of HSC20, causing rapid degradation of SDHB. In the absence of SDHB, respiration was undetectable in UOK269 cells, succinate was elevated to 351.4 ± 63.2 nmol/mg cellular protein, and glutamine became the main source of TCA cycle metabolites through reductive carboxylation.Furthermore, HIF1α, but not HIF2α, increased markedly and the cells showed a strong DNA CpG island methylatorphenotype (CIMP). Biochemical and bioinformatic screening revealed that 37% of disease-causing missense mutations in SDHB were located in either the L(I)YR Fe-S transfer motifs or in the 11 Fe-S cluster-ligating cysteines.
  
  
  CONCLUSIONS
  These findings provide a conceptual framework for understanding how particular mutations disproportionately cause the loss of SDH activity, resulting in accumulation of succinate and metabolic remodeling in SDHB cancer syndromes.
authors.forename: Neetu
authors.initials: N
authors.lastname: Saxena
authors.forename: Nunziata
authors.initials: N
authors.lastname: Maio
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Crooks
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Ricketts
authors.forename: Youfeng
authors.initials: Y
authors.lastname: Yang
authors.forename: Ming-Hui
authors.initials: MH
authors.lastname: Wei
authors.forename: Teresa W-M
authors.initials: TW
authors.lastname: Fan
authors.forename: Andrew N
authors.initials: AN
authors.lastname: Lane
authors.forename: Carole
authors.initials: C
authors.lastname: Sourbier
authors.forename: Anamika
authors.initials: A
authors.lastname: Singh
authors.forename: J Keith
authors.initials: JK
authors.lastname: Killian
authors.forename: Paul S
authors.initials: PS
authors.lastname: Meltzer
authors.forename: Cathy D
authors.initials: CD
authors.lastname: Vocke
authors.forename: Tracey A
authors.initials: TA
authors.lastname: Rouault
authors.forename: W Marston
authors.initials: WM
authors.lastname: Linehan
mesh_terms: D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism; D002292:Carcinoma, Renal Cell / Q000235:genetics* / Q000378:metabolism*; D045744:Cell Line, Tumor; D018899:CpG Islands / Q000235:genetics; D019175:DNA Methylation; D018095:Germ-Line Mutation; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D007506:Iron-Sulfur Proteins / Q000378:metabolism*; D007680:Kidney Neoplasms / Q000235:genetics / Q000378:metabolism; D018832:Molecular Chaperones / Q000378:metabolism*; D009154:Mutation; D020125:Mutation, Missense; D010641:Phenotype; D017354:Point Mutation; D013385:Succinate Dehydrogenase / Q000172:deficiency* / Q000235:genetics*; D000099162:Endothelial PAS Domain-Containing Protein 1
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007506:Iron-Sulfur Proteins; D018832:Molecular Chaperones; D013385:Succinate Dehydrogenase; D000099162:Endothelial PAS Domain-Containing Protein 1; C497442:HIF1A protein, human; C490651:HSCB protein, human; C108095:SDHB protein, human