A nuclear export sequence in GPN-loop GTPase 1, an essential protein for nuclear targeting of RNA polymerase II, is necessary and sufficient for nuclear export

► The GTPase Gpn1 is essential for the nuclear accumulation of RNA polymerase II. ► Although Gpn1 is cytoplasmic, it shuttles between the cytoplasm and cell nucleus. ► We identify the nuclear export sequence (NES) that mediates nuclear export of Gpn1 ► Gpn1 NES is highly conserved and both, necessary and sufficient, for nuclear export. ► Molecular modeling of Gpn1 revealed that NES accessibility equals functionality.