Saturday, August 12, 2006
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. Apoptosis eliminates extraneous cells from the developing body; and disposes of cells that sustain irreparable harm to their DNA or are infected with microorganisms.
The researchers photographed individual cells undergoing that process, allowing investigators to observe the release of certain proteins from pores in the membranes of mitochondria. These cellular structures contain enzymes that extract energy from food molecules, and the space within the membrane surrounding them holds a variety of proteins that are released during apoptosis.
Results of the study indicate the formation of pores in the mitochondrial membranes is a rapid process that allows a nearly simultaneous rather than a sequential release of many apoptosis proteins, according to Douglas Green, Ph.D., chair of the St. Jude Department of Immunology. Green is senior author of a report on this work that appears in the August 1 issue of Proceedings of the National Academy of Sciences (PNAS).
The above is based on "Different mitochondrial intermembrane space proteins are released during apoptosis in a manner that is coordinately initiated but can vary in duration" which is open access: Abstract | Full Text