{"title":"A novel role of AURKA kinase in erythroblast enucleation.","authors":"Yuanlin Xu, Peijun Jia, Yating Li, Huan Zhang, Jingxin Zhang, Wanxin Li, Yazhe Zhen, Yan Li, Jiaming Cao, Tingting Zheng, Yihan Wang, Yanyan Liu, Xiuli An, Shijie Zhang","doi":"10.3324/haematol.2023.284873","DOIUrl":null,"url":null,"abstract":"<p><p>Generation of mammalian red blood cells requires the expulsion of polarized nuclei late in terminal erythroid differentiation. However, the mechanisms by which spherical erythroblasts determine the direction of nuclear polarization and maintain asymmetry during nuclear expulsion are poorly understood. Given the analogy of erythroblast enucleation to asymmetric cell division and the key role of Aurora kinases in mitosis, we sought to investigate the function of Aurora kinases in erythroblast enucleation. We found that AURKA (Aurora kinase A) is abundantly expressed in orthochromatic erythroblasts. Intriguingly, high-resolution confocal microscopy analyses revealed that AURKA co-localized with the centrosome on the side of the nucleus opposite its membrane contact point during polarization and subsequently translocated to the anterior end of the protrusive nucleus upon nuclear exit. Mechanistically, AURKA regulated centrosome maturation and localization via interaction with γ-tubulin to provide polarization orientation for the nucleus. Furthermore, we identified ECT2 (epithelial cell transforming 2), a guanine nucleotide exchange factor, as a new interacting protein and ubiquitination substrate of AURKA. After forming the nuclear protrusion, AURKA translocated to the anterior end of the protrusive nucleus to directly degrade ECT2, which is partly dependent on kinase activity of AURKA. Moreover, knockdown of ECT2 rescued impaired enucleation caused by AURKA inhibition. Our findings have uncovered a previously unrecognized role of Aurora kinases in the establishment of nuclear polarization and eventual nuclear extrusion and provide new mechanistic insights into erythroblast enucleation.</p>","PeriodicalId":12964,"journal":{"name":"Haematologica","volume":null,"pages":null},"PeriodicalIF":8.2000,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11532702/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Haematologica","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.3324/haematol.2023.284873","RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"HEMATOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Generation of mammalian red blood cells requires the expulsion of polarized nuclei late in terminal erythroid differentiation. However, the mechanisms by which spherical erythroblasts determine the direction of nuclear polarization and maintain asymmetry during nuclear expulsion are poorly understood. Given the analogy of erythroblast enucleation to asymmetric cell division and the key role of Aurora kinases in mitosis, we sought to investigate the function of Aurora kinases in erythroblast enucleation. We found that AURKA (Aurora kinase A) is abundantly expressed in orthochromatic erythroblasts. Intriguingly, high-resolution confocal microscopy analyses revealed that AURKA co-localized with the centrosome on the side of the nucleus opposite its membrane contact point during polarization and subsequently translocated to the anterior end of the protrusive nucleus upon nuclear exit. Mechanistically, AURKA regulated centrosome maturation and localization via interaction with γ-tubulin to provide polarization orientation for the nucleus. Furthermore, we identified ECT2 (epithelial cell transforming 2), a guanine nucleotide exchange factor, as a new interacting protein and ubiquitination substrate of AURKA. After forming the nuclear protrusion, AURKA translocated to the anterior end of the protrusive nucleus to directly degrade ECT2, which is partly dependent on kinase activity of AURKA. Moreover, knockdown of ECT2 rescued impaired enucleation caused by AURKA inhibition. Our findings have uncovered a previously unrecognized role of Aurora kinases in the establishment of nuclear polarization and eventual nuclear extrusion and provide new mechanistic insights into erythroblast enucleation.
期刊介绍:
Haematologica is a journal that publishes articles within the broad field of hematology. It reports on novel findings in basic, clinical, and translational research.
Scope:
The scope of the journal includes reporting novel research results that:
Have a significant impact on understanding normal hematology or the development of hematological diseases.
Are likely to bring important changes to the diagnosis or treatment of hematological diseases.