Identification and expression analysis of a novel CW-type zinc finger protein MORC2 in cancer cells.

Microrchidia2 (MORC2) is a member of the MORC protein family that is localized to both the nucleus and cytoplasm when transiently expressed in gastric cancer cells. We identified and analyzed the functional domains of MORC2, which has specific unique structural characteristics compared to the other MORC proteins. Our data showed that nuclear localization signals (NLS) of MORC2 was mainly dependent on the NLS amino acids (aa) 657-781 and cytoplasmic localization of MORC2 was attributed to the nuclear export signal (NES) aa 481-657. Moreover, the NLS appears to predominate over the NES in the localization of full-length human MORC2 indicating that MORC2 is localized mainly in the nucleus. Our results also demonstrated that the NLS (aa 657-781) and proline-rich domain within MORC2 C-terminus were required for the transcriptional repressive role in cancer cells.