A novel role of farnesylation in targeting a mitotic checkpoint protein, human Spindly, to kinetochores.
Bottom Line: We showed that hSpindly is farnesylated in vivo and farnesylation is essential for its interaction with the RZZ complex and hence KT localization.FTI treatment and hSpindly knockdown displayed the same mitotic phenotypes, indicating that hSpindly is a key FTI target in mitosis.Our data show a novel role of lipidation in targeting a checkpoint protein to KTs through protein-protein interaction.
Affiliation: Department of Oncology, University of Alberta, Edmonton, Alberta, Canada T6G 1Z2.Show MeSH
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Mentions: Because the C terminus of hSpindly is required for KT localization through the CAAX farnesylation motif, we hypothesized that any farnesylation motif on the C terminus of hSpindly regardless of the specific residues is sufficient for it to undergo farnesylation and target it to KTs. We replaced the CPQQ residues of hSpindly with the CKTQ (CENP-E) and CKVQ (CENP-F) farnesylation motifs, referred to as Spindly-E and Spindly-F, respectively. Both Spindly-E and -F localized to KTs during prometaphase, supporting our hypothesis that the exact amino acid sequence is not important and the ability to be farnesylated is sufficient for hSpindly KT localization (Fig. 5, A and B; and Fig. S1 G).
Affiliation: Department of Oncology, University of Alberta, Edmonton, Alberta, Canada T6G 1Z2.