Roles of VRK1 as a new player in the control of biological processes required for cell division.

Cell division, in addition to an accurate transmission of genetic information to daughter cells, also requires the temporal and spatial coordination of several biological processes without which cell division would not be feasible. These processes include the temporal coordination of DNA replication and chromosome segregation, regulation of nuclear envelope disassembly and assembly, chromatin condensation and Golgi fragmentation for its redistribution into daughter cells, among others. However, little is known regarding regulatory proteins and signalling pathways that might participate in the coordination of all these different biological functions. Such regulatory players should directly have a role in the processes leading to cell division. VRK1 (Vaccinia-related kinase 1) is an early response gene required for cyclin D1 expression, regulates p53 by a specific Thr18 phosphorylation, controls chromatin condensation by histone phosphorylation, nuclear envelope assembly by phosphorylation of BANF1, and participates in signalling required for Golgi fragmentation late in the G2 phase. We propose that VRK1, a Ser-Thr kinase, might be a candidate to play an important coordinator role in these cell division processes as part of a novel signalling pathway.