Golgi Peptide Can Trigger Apoptosis

A team of cellular and molecular biologists have identified a peptide that is the smallest molecule found so far that can trigger the sequence of events leading to apoptosis (programmed cell death).

Investigators at the Albert Einstein College of Medicine (New York City, NY, USA) have been studying the role of intracellular organelles on apoptosis. In the current study, they focused on the Golgi apparatus, the cell's main site for modification and distribution of proteins and other large molecules. The Golgi apparatus is a stack of membrane-bound vesicles that package macromolecules for transport elsewhere in the cell. The enzymatic or hormonal contents of lysosomes, peroxisomes, and secretory vesicles are packaged in membrane-bound vesicles at the periphery of the organelle.

The investigators reported in the January 16, 2009, issue of the Journal of Biological Chemistry (JBC) that a 205 amino acid protein fragment generated by cleavage of the Golgi's p115 protein could be further reduced to a 26 amino acid peptide, which retained the p115 protein's ability to trigger apoptosis. Onset of apoptosis required translocation of the active peptide from the cytoplasm to the nucleus of the cell.

Professor Dennis Shields, who died unexpectedly in December 2008, directed the research effort. "Dennis Shields was one of our most outstanding scientists," said Dr. E. Richard Stanley, chairman of developmental and molecular biology at the Albert Einstein College of Medicine. "His efforts to uncover fundamental mechanisms governing how cells work has led to new ways of thinking about apoptosis, in particular, how the Golgi regulates this process."

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