biostudies-literatureWeber JEuropean Molecular Biology OrganizationDanmarks Frie ForskningsfondWellcome TrustNovo Nordisk Fonden1133-1141.e4https://www.ebi.ac.uk/biostudies/studies/S-EPMC7617963biostudies-literatureUnknown34(5)The outer corona plays an essential role at the onset of mitosis by expanding to maximize microtubule attachment to kinetochores.¹^,² The low-density structure of the corona forms through the expansion of unattached kinetochores. It comprises the RZZ complex, the dynein adaptor Spindly, the plus-end directed microtubule motor centromere protein E (CENP-E), and the Mad1/Mad2 spindle-assembly checkpoint proteins.³^,⁴^,⁵^,⁶^,⁷^,⁸^,⁹^,¹⁰ CENP-E specifically associates with unattached kinetochores to facilitate chromosome congression,¹¹^,¹²^,¹³^,¹⁴^,¹⁵^,¹⁶ interacting with BubR1 at the kinetochore through its C-terminal region (2091-2358).¹⁷^,¹⁸^,¹⁹^,²⁰^,²¹ We recently showed that CENP-E recruitment to BubR1 at the kinetochores is both rapid and essential for correct chromosome alignment. However, CENP-E is also recruited to the outer corona by a second, slower pathway that is currently undefined.¹⁹ Here, we show that BubR1-independent localization of CENP-E is mediated by a conserved loop that is essential for outer-corona targeting. We provide a structural model of the entire CENP-E kinetochore-targeting domain combining X-ray crystallography and Alphafold2. We reveal that maximal recruitment of CENP-E to unattached kinetochores critically depends on BubR1 and the outer corona, including dynein. Ectopic expression of the CENP-E C-terminal domain recruits the RZZ complex, Mad1, and Spindly, and prevents kinetochore biorientation in cells. We propose that BubR1-recruited CENP-E, in addition to its essential role in chromosome alignment to the metaphase plate, contributes to the recruitment of outer corona proteins through interactions with the CENP-E corona-targeting domain to facilitate the rapid capture of microtubules for efficient chromosome alignment and mitotic progression.Current biology : CBA conserved CENP-E region mediates BubR1-independent recruitment to the outer corona at mitotic onset.PMC7617963219413DFF-3101-00075207430207430/Z/17/ZNNF19OC0058504203149Eibes SLegal TLezcano APGluszek-Kustusz AWelburn JPIPaterson CWeber JDavies ORBarisic MfalseA conserved CENP-E region mediates BubR1-independent recruitment to the outer corona at mitotic onset.The outer corona plays an essential role at the onset of mitosis by expanding to maximize microtubule attachment to kinetochores.¹^,² The low-density structure of the corona forms through the expansion of unattached kinetochores. It comprises the RZZ complex, the dynein adaptor Spindly, the plus-end directed microtubule motor centromere protein E (CENP-E), and the Mad1/Mad2 spindle-assembly checkpoint proteins.³^,⁴^,⁵^,⁶^,⁷^,⁸^,⁹^,¹⁰ CENP-E specifically associates with unattached kinetochores to facilitate chromosome congression,¹¹^,¹²^,¹³^,¹⁴^,¹⁵^,¹⁶ interacting with BubR1 at the kinetochore through its C-terminal region (2091-2358).¹⁷^,¹⁸^,¹⁹^,²⁰^,²¹ We recently showed that CENP-E recruitment to BubR1 at the kinetochores is both rapid and essential for correct chromosome alignment. However, CENP-E is also recruited to the outer corona by a second, slower pathway that is currently undefined.¹⁹ Here, we show that BubR1-independent localization of CENP-E is mediated by a conserved loop that is essential for outer-corona targeting. We provide a structural model of the entire CENP-E kinetochore-targeting domain combining X-ray crystallography and Alphafold2. We reveal that maximal recruitment of CENP-E to unattached kinetochores critically depends on BubR1 and the outer corona, including dynein. Ectopic expression of the CENP-E C-terminal domain recruits the RZZ complex, Mad1, and Spindly, and prevents kinetochore biorientation in cells. We propose that BubR1-recruited CENP-E, in addition to its essential role in chromosome alignment to the metaphase plate, contributes to the recruitment of outer corona proteins through interactions with the CENP-E corona-targeting domain to facilitate the rapid capture of microtubules for efficient chromosome alignment and mitotic progression.2024-01-01T00:00:00Z2024 Mar2026-03-10T23:05:59.111Z2025-08-12T03:05:01.955ZS-EPMC76179633835473510.1016/j.cub.2024.01.042