title: Stress-induced expression of a novel variant of human fumarate hydratase (FH).
abstract: 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 1b, 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 (HTB 115) by nine- and fourfold, respectively. These results suggest that FHv has an alternative function outside the TCAC related to cellular stress response.
authors.affiliation: Department of Medical Genetics, Biomedicum Helsinki, University of Helsinki, Helsinki, Finland.
authors.forename: Heli J
authors.initials: HJ
authors.lastname: Lehtonen
authors.forename: Sanna K
authors.initials: SK
authors.lastname: Ylisaukko-Oja
authors.forename: Maija
authors.initials: M
authors.lastname: Kiuru
authors.forename: Auli
authors.initials: A
authors.lastname: Karhu
authors.forename: Rainer
authors.initials: R
authors.lastname: Lehtonen
authors.forename: Sakari
authors.initials: S
authors.lastname: Vanharanta
authors.forename: Anu
authors.initials: A
authors.lastname: Jalanko
authors.forename: Lauri A
authors.initials: LA
authors.lastname: Aaltonen
authors.forename: Virpi
authors.initials: V
authors.lastname: Launonen
mesh_terms: D001483:Base Sequence; D015153:Blotting, Western; D002460:Cell Line; D018076:DNA, Complementary; D005455:Fluorescent Antibody Technique; D005649:Fumarate Hydratase / Q000235:genetics*; D005786:Gene Expression Regulation; D006801:Humans; D008969:Molecular Sequence Data; D014176:Protein Biosynthesis; D013312:Stress, Physiological / Q000235:genetics*; D013347:Subcellular Fractions / Q000201:enzymology
chemical_list: D018076:DNA, Complementary; D005649:Fumarate Hydratase