Vimentin intermediate filaments (IF) are responsible for regulation of cell attachment and subcellular organization. Using an in vitro model system of human prostate epithelial cells (267B1-XR), we demonstrate that a series of vimentin proteolytic fragments represent some of the differentially expressed proteins in 2D-gel profiles of the apoptotic cells undergoing ionizing radiation-induced cell death. A caspase-sensitive motif search suggests that the type III IF protein (vimentin) is subject to proteolysis to promote the execution phase of apoptosis, in a manner similar to the well-established type V (lamins) and type I (keratins 18, 19) IF proteins. Furthermore, vimentin and a few of its derived polypeptides, reported to be specific to the apoptotic process, correspond to ubiquinated proteins, thus pointing to the complex interrelationships of protein ubiquination in solubilizing the IF network during apoptosis.
|Number of pages||7|
|Journal||Biochemical and Biophysical Research Communications|
|Publication status||Published - 19 Aug 1998|
Bibliographical noteFunding Information:
These studies were funded by NIH grant CA45408 to A.D. The 2D-gel electrophoresis experiments were performed in the Shared Resource Facility of the Vincent T. Lombardi Cancer Center supported by an NCI-funded Cancer Center Support Grant (P30-CA51008). The authors thank Sheri Sharareh, Suneetha Menon, and Xiaojun Zou for technical assistance, and Elaine North for preparation of the manuscript.
- Ionizing radiation
- Prostate cells