Phosphorylation of Ephexin4 at Ser-41 contributes to chromosome alignment via RhoG activation in cell division.

ABSTRACT: Ephexin proteins are guanine nucleotide exchange factors for the Rho GTPases. We reported that Ephexin4 regulates M-phase progression downstream of phosphorylated EphA2, a receptor-type tyrosine kinase, through RhoG activation; however, the regulation of Ephexin4 during M phase remains unknown. In this study, a novel Ephexin4 phosphorylation site was identified at Ser41, exclusively in M phase. Ephexin4 knockdown prolonged the duration of M phase by activating the spindle assembly checkpoint, at which BubR1 was localized at the kinetochores of the misaligned chromosomes. This delay was alleviated by re-expression of wild-type, but not S41A Ephexin4. The Ephexin4 knockdown caused chromosome misalignment and reduced the RhoG localization to the plasma membrane. These phenotypes were rescued

SUBMITTER: Yasutake R 

PROVIDER: S-EPMC11758948 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature