Rearrangement of nuclear ribonucleoprotein (RNP)‐containing structures during apoptosis and transcriptional arrest

Abstract
The aim of this paper is to review the data in the literature concerning ribonucleoprotein components during apoptosis, where a major rearrangement of RNPs takes place. In parallel with chromatin changes, the nucleoplasmic constituents (perichromatin fibrils; perichromatin granules; interchromatin granules and nuclear bodies) as well as the nucleoli aggregate into heterogeneous clusters called HERDS, in the interchromatin space. Later, these RNP-containing structures are extruded from the nucleus and leave the cell within cytoplasmic blebs. We propose also a role for HERDS as markers of irreversible transcriptional arrest.