Fbxo30 Regulates Mammopoiesis by Targeting the Bipolar Mitotic Kinesin Eg5.
Fbxo30 is an orphan member of the F-box protein family with no known substrate or function. Here we report that, while Fbxo30(-/-) mice exhibit normal development, growth, lifespan, and fertility, the females fail to nurture their offspring as a result of defective mammopoiesis. Mass spectrometry analysis of Fbxo30-associated proteins revealed that Fbxo30 specifically interacts with the bipolar spindle kinesin EG5 (encoded by Kif11). As a result, Fbxo30 targets Eg5 for ubiquitinylation and controls its oscillation during the cell cycle. Correlated with EG5 dysregulation, Fbxo30(-/-) mammary epithelial cells exhibit multiple defects in centrosome homeostasis, mitotic spindle formation, and proliferation. Effects on proliferation, centrosome homeostasis, and mammopoiesis in the Fbxo30(-/-) mice were rescued through normalization of Eg5 activity using shRNA and/or an EG5 inhibitor. Our data reveal the Fbxo30-Eg5 interaction as a critical checkpoint in mammopoiesis and a critical role for ubiquitinylation-regulated Eg5 oscillation in the cell cycle.
Center for Cancer and Immunology Research, Children's Research Institute, Children's National Medical Center, Washington, DC 20010, USA.
Yan
Y
Liu
Center for Cancer and Immunology Research, Children's Research Institute, Children's National Medical Center, Washington, DC 20010, USA. Electronic address: ywang@cnmc.org.
Yin
Y
Wang
Key Laboratory for Infection and Immunity, Institute of Biophysics, Chinese Academy of Science, Beijing 100101, China.
Zhanwen
Z
Du
Key Laboratory for Infection and Immunity, Institute of Biophysics, Chinese Academy of Science, Beijing 100101, China.
Xiaoli
X
Yan
Center for Cancer and Immunology Research, Children's Research Institute, Children's National Medical Center, Washington, DC 20010, USA. Electronic address: panz@cnmc.org.
Pan
P
Zheng
Center for Cancer and Immunology Research, Children's Research Institute, Children's National Medical Center, Washington, DC 20010, USA. Electronic address: yaliu@cnmc.org.
Yang
Y
Liu
D000818:Animals; D002452:Cell Count; D002454:Cell Differentiation; D019070:Cell Lineage / Q000235:genetics; D049109:Cell Proliferation; D043171:Chromosomal Instability; D044783:F-Box Proteins / Q000378:metabolism*; D005260:Female; D018390:Gene Targeting; D045325:HCT116 Cells; D006801:Humans; D016547:Kinesins / Q000378:metabolism*; D008321:Mammary Glands, Animal / Q000254:growth & development* / Q000378:metabolism*; D051379:Mice; D008938:Mitosis; D009154:Mutation / Q000235:genetics; D008941:Spindle Apparatus / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism
D044783:F-Box Proteins; D044767:Ubiquitin-Protein Ligases; C521052:Kif11 protein, mouse; D016547:Kinesins