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    Douglas R. Green, PhDDouglas R. Green, PhD

    Key event in cell death occurs as single, quick event

    St. Jude researchers discover process is not step-by-step as previously thought; discovery unlocks more information on how cells “commit suicide.”

    Scientists at St. Jude Children's Research Hospital have demonstrated that a key event during apoptosis (cell suicide), occurs as a single quick event, rather than as a step-by-step process.

    The researchers photographed individual cells undergoing that process, allowing them to observe the release of certain proteins from pores in the membranes of cellular structures called mitochondria.

    However, one protein, apoptosis-inducing factor (AIF), escaped from the mitochondrial membrane much more slowly and incompletely, starting with the release of cytochrome c but continuing over the next few hours, according to Douglas Green, PhD, chair of the St. Jude Department of Immunology. Green is the senior author of a report on this work that appears in the August 1 issue of Proceedings of the National Academy of Sciences. The St. Jude researchers concluded that while AIF is known to regulate other cellular processes, the protein itself is not involved in triggering apoptosis.

    The study also highlights the importance of the Bcl-2 family of proteins in regulating the formation of pores in the mitochondrial membrane, Green said.

    Other authors of the study include Cristina Munoz-Pinedo (Institute of Biomedical Investigations of Bellvitge, Barcelona, Spain); Ana Guio-Carrion (Genomics Institute for the Novartis Research Foundation, San Diego, Calif.); Patrick Fitzgerald (St. Jude) and Donald Newmeyer (La Jolla Institute for Allergy and Immunology).

    This work was supported in part by National Institutes of Health, ALSAC and Secretaría de Estado de Universidades Investigación and the Fondo de Investigaciónes Sanitariás of Spain.

     

    August 2006