Fumarate hydratase (FH) is an enzyme of the mitochondrial tricarboxylic acid cycle (TCAC). Here we report the characterization of a novel FH variant (FHv) that contains an alternative exon lb, thus lacking the mitochondrial signal sequence. Distinct from mitochondrial FH, FHv localized to cytosol and nucleus and lacked FH enzyme activity. FHv was expressed ubiquitously in human fetal and adult tissues. Heat shock and prolonged hypoxia increased FHv expression in a cell line (HTB115) by nine- and fourfold, respectively. These results suggest that FHv has an alternative function outside the TCAC related to cellular stress response.
- Alternative exon
- Fumarate hydratase (FH)
- Heat shock
- Hereditary leiomyomatosis and renal cell cancer (HLRCC)
- Tricarboxylic acid cycle (TCAC)
ASJC Scopus subject areas
- Molecular Biology