IDENTIFICATION OF A NEW COILED BODY COMPONENT

Coiled bodies are small, round nuclear inclusions that have been ident ified in many somatic cell types. Equivalent structures are found in t he germinal vesicles of amphibian and insect oocytes, known respective ly as sphere organelles and Binnenkorper. Their functions are not know n, but their molecular composition is being brought to light. In addit ion to the nucleolar protein, fibrillarin, coiled bodies contain DNA t opoisomerase I and an array of RNA processing molecules characteristic of spliceosomes. One coiled body protein absent from nucleoli and spl iceosomes, known as p80-coilin, has also been described. We have now i dentified pigpen, a new member of the EWS family of proteins, as a sec ond protein enriched in coiled bodies. In an earlier report we found t hat pigpen's structure and expression pattern were suggestive of a rol e in endothelial cell proliferation and differentiation. In this brief report we characterize pigpen's nuclear compartment and describe its reorganization during mitosis. (C) 1996 Academic Press, Inc.