Journal article
Designed FHIT alleles establish that Fhit-induced apoptosis in cancer cells is limited by substrate binding
Proceedings of the National Academy of Sciences of the United States of America, Vol.100(4), pp.1592-1597
02/18/2003
DOI: 10.1073/pnas.0437915100
PMCID: PMC149877
PMID: 12574506
Abstract
The FHIT gene is inactivated early in the development of many human tumors, and Fhit-deficient mice have increased cancer incidence. Viral reexpression of Fhit kills Fhit-deficient cells by induction of apoptosis. Fhit, a member of branch 2 of the histidine-triad superfamily of nucleoside monophosphate hydrolases and transferases, is a diadenosine polyphosphate hydrolase, the active-site histidine of which is not required for tumor suppression. To provide a rigorous test of the hypothesis that Fhit function depends on forming a complex with substrates, we designed a series of alleles of Fhit intended to reduce substrate-binding andor hydrolytic rates, characterized these mutants biochemically, and then performed quantitative cell-death assays on cancer cells virally infected with each allele. The allele series covered defects as great as 100,000-fold in k(cat) and increases as large as 30-fold in K(M). Nonetheless, when mutant FHIT genes were expressed in two human cancer cell lines containing FHIT deletions, reductions in apoptotic activity correlated exclusively with K(M). Mutants with 2- and 7-fold increases in K(M) significantly reduced apoptotic indices, whereas the mutant with a 30-fold increase in K(M) retained little cellular function. These data indicate that the proapoptotic function of Fhit is limited by substrate binding and is unrelated to substrate hydrolysis.
Details
- Title: Subtitle
- Designed FHIT alleles establish that Fhit-induced apoptosis in cancer cells is limited by substrate binding
- Creators
- Francesco Trapasso - Genetics and Molecular Biology Program, Kimmel Cancer Center, Philadelphia, PA 19107, USAAgnieszka KrakowiakRossano CesariJeffrey ArklesSai YendamuriHideshi IshiiAndrea VecchioneTamotsu KurokiPawel BieganowskiHelen C PaceKay HuebnerCarlo M CroceCharles Brenner
- Resource Type
- Journal article
- Publication Details
- Proceedings of the National Academy of Sciences of the United States of America, Vol.100(4), pp.1592-1597
- Publisher
- United States
- DOI
- 10.1073/pnas.0437915100
- PMID
- 12574506
- PMCID
- PMC149877
- ISSN
- 0027-8424
- eISSN
- 1091-6490
- Grant note
- CA77738 / NCI NIH HHS P30 CA056036 / NCI NIH HHS R01 CA075954-07 / NCI NIH HHS P01 CA077738 / NCI NIH HHS R01 CA075954 / NCI NIH HHS CA56036 / NCI NIH HHS CA75954 / NCI NIH HHS
- Language
- English
- Date published
- 02/18/2003
- Academic Unit
- Biochemistry and Molecular Biology; Internal Medicine
- Record Identifier
- 9983788598002771
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