Functional characterization of AIBp, a novel Aurora-A binding protein in centrosome structure and spindle formation.
Aurora-A is involved in chromosome alignment, centrosome maturation, mitotic spindle assembly and regards to an oncogene. Aurora-A is also known to bind to several other proteins affecting its up-regulation or down-regulation and localization. However, how these different binding signals work together to regulate Aurora-A is not properly known. To explore more Aurora-A interacting proteins, the low-copy yeast two-hybrid screening using Aurora-A as bait protein was performed. One novel gene, AIBp, was demonstrated to associate with Aurora-A by the yeast two-hybrid method and in vitro GST pull-down assay. Molecular characterization showed that AIBp possessed a binding site at the C-terminal with Aurora-A (kinase domain). Interestingly, AIBp also interacts with hNinein at the N-terminal, which overlaps with a previously reported hNinein and GSK3beta binding site. Using a kinase assay, AIBp interacts with the Aurora-A kinase domain functions as a positive regulator, whereas AIBp binding to hNinein appears to block the phosphorylation of hNinein by both Aurora-A and GSK3beta. siRNA-mediated elimination of AIBp from HeLa cells, results in a doughnut-like shape, asymmetrical spindle pole and multiple spindle pole formation. We also demonstrated that both AIBp and Aurora-A are co-overexpressed in various brain tumors. These studies demonstrate that AIBp may not only be required for the dynamic movement of Aurora-A at the centrosomes and spindle apparatus during the cell cycle, but may also be important during brain tumorigenesis.
Lieu
Ann-Shung
AS
Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan, ROC.
Cheng
Tai-Shan
TS
Chou
Chia-Hua
CH
Wu
Chia-Hung
CH
Hsu
Chia-Yi
CY
Huang
Chi-Ying F
CY
Chang
Li-Kwan
LK
Loh
Joon-Khim
JK
Chang
Chung-Shing
CS
Hsu
Ching-Mei
CM
Howng
Shen-Long
SL
Hong
Yi-Ren
YR
D000595:Amino Acid Sequence; D064127:Aurora Kinases; D001483:Base Sequence; D001932:Brain Neoplasms / Q000235:genetics / Q000473:pathology; D002277:Carcinoma / Q000235:genetics / Q000473:pathology; D002352:Carrier Proteins / Q000378:metabolism / Q000502:physiology*; D018385:Centrosome / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D003598:Cytoskeletal Proteins / Q000378:metabolism; D004268:DNA-Binding Proteins; D005260:Female; D006367:HeLa Cells; D006801:Humans; D008297:Male; D008869:Microtubule-Associated Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D008954:Models, Biological; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D008941:Spindle Apparatus / Q000378:metabolism* / Q000502:physiology; D014018:Tissue Distribution; D020798:Two-Hybrid System Techniques
C553277:AUNIP protein, human; D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins; D008869:Microtubule-Associated Proteins; C512806:NIN protein, human; D009687:Nuclear Proteins; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases