Plastins: Versatile modulators of actin organization in (patho)physiological cellular processes

Department of Medical Protein Research, Flanders Interuniversity Institute for Biotechnology (VIB), Ghent University, Faculty of Medicine and Health Sciences, Albert Baertsoenkaai 3, B-9000 Ghent, Belgium.
Acta Pharmacologica Sinica (Impact Factor: 2.91). 08/2005; 26(7):769-79. DOI: 10.1111/j.1745-7254.2005.00145.x
Source: PubMed


Many actin-binding proteins are expressed in eukaryotic cells. These polypeptides assist in stabilizing and rearranging the organization of the actin cytoskeleton in response to external stimuli, or during cell migration and adhesion. Here we review a particular set of actin-binding proteins called plastins. Plastins (also called fimbrins) belong to a subclass of actin-binding proteins known as actin bundling proteins. Three isoforms have been characterized in mammals: T-plastin is expressed in cells from solid tissue, whereas L-plastin occurs predominantly in hematopoietic cells. The third isoform, I-plastin, is specifically expressed in the small intestine, colon and kidney. These proteins share the unique property of cross-linking actin filaments into tight bundles. Although plastins are primarily involved in regulation of the actin cytoskeleton, they possess some unique features. For instance, they are implicated in invasion by pathogenic bacteria such as Shigella flexneri and Salmonella typhimurium. Also, L-plastin plays an important role in leukocyte function. T-plastin, on the other hand, is possibly involved in DNA repair. Finally, both T- and L-plastin are implicated in several diseases, and L-plastin is considered to be a valuable marker for cancer.

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    • "The results showed that a high level of L-plastin expression was identified in RMCCA1 cells cultured in matrix gel (Fig. 2B). A previous study demonstrated that L-plastin localizes to actin-rich membrane structures involved in locomotion, adhesion and immune defense, thereby implying that L-plastin is involved in the organization of the actin cytoskeleton (17). In addition, L-plastin has also been detected in solid tumors of epithelial and mesenchymal origin and has been suggested to be involved in cancer cell invasion (18). "
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