Role of Ran GTPase in cell cycle regulation

Ran, a member of the Ras GTPase superfamily, is a multifunctional protein and abundant in the nucleus. Many evidences suggest that Ran and its interacting proteins are involved in multiple aspects of the cell cycle regulation. So far it has been conformed that Ran and its interacting proteins control the nucleocytoplasmic transport, the nuclear envelope (NE) assembly, the DNA replication and the spindle assembly, although many details of the mechanisms are waiting for elucidation. It has also been implicated that Ran and its interacting proteins are involved in regulating the integrity of the nuclear structure, the mRNA transcription and splicing, and the RNA transport from the nucleus to the cytoplasm. In this review we mainly discuss the mechanisms by which Ran and its interacting proteins regulate NE assembly, DNA replication and spindle assembly.