title: A novel 21-kDa cytochrome c-releasing factor is generated upon treatment of human leukemia U937 cells with geranylgeraniol.
abstract: Geranylgeraniol (GGO) induces apoptosis in various lines of human tumor cells through a mitochondrion-dependent pathway. The present study describes identification of a 21-kDa cytochrome c-releasing factor that appears in the cytosolic fraction after treatment of human leukemia U937 cells with GGO. Incubation of isolated mitochondria with a lysate of U937 cells that had been treated with GGO resulted in the release of cytochrome c from the mitochondria. Utilizing this cell-free system, we purified a 21-kDa protein that induced the release of cytochrome c from mitochondria and appeared to be involved in the apoptosis that is induced in U937 cells by GGO. We designated this protein cytochrome c-releasing factor 21 (CRF21). Overexpression of CRF21 in HeLa cells induced the release of cytochrome c from mitochondria, with subsequent apoptosis. Our results suggest that CRF21 might play an important role in the induction of apoptosis by GGO in leukemia U937 cells.
authors.affiliation: Laboratory of Biological Chemistry, School of Pharmaceutical Sciences, Showa University, Tokyo, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Masuda
authors.forename: Sayoko
authors.initials: S
authors.lastname: Maeda
authors.forename: Akiko
authors.initials: A
authors.lastname: Watanabe
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Sano
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Aiuchi
authors.forename: Shigeo
authors.initials: S
authors.lastname: Nakajo
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Itabe
authors.forename: Kazuyasu
authors.initials: K
authors.lastname: Nakaya
mesh_terms: D000595:Amino Acid Sequence; D017209:Apoptosis; D045304:Cytochromes c / Q000378:metabolism*; D004224:Diterpenes / Q000494:pharmacology*; D006367:HeLa Cells; D006801:Humans; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000096:biosynthesis*; D020298:U937 Cells
chemical_list: D004224:Diterpenes; D024101:Mitochondrial Proteins; D045304:Cytochromes c; C017338:geranylgeraniol