Aurora-A kinase-inactive mutants disrupt the interaction with Ajuba and cause defects in mitotic spindle formation and G2/M phase arrest in HeLa cells.
Aurora-A is a centrosome-localized serine/threonine kinase that is overexpressed in multiple human cancers. We previously reported an intramolecular inhibitory regulation of Aurora-A between its N-terminal regulatory domain (Nt, amino acids [aa] 1-128) and the C-terminal catalytic domain (Cd, aa 129-403). Here, we demonstrate that although both Aurora-A mutants (AurA-K250G and AurA-D294G/Y295G) lacked interactions between the Nt and Cd, they also failed to interact with Ajuba, an essential activator of Aurora-A, leading to loss of kinase activity. Additionally, overexpression of either of the mutants resulted in centrosome amplification and mitotic spindle formation defects. Both mutants were also able to cause G2/M arrest and apoptosis. These results indicate that both K250 and D294/Y295 are critical for direct interaction between Aurora-A and Ajuba and the function of the Aurora-A complex in cell cycle progression.
State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, 220 Handan Road, Shanghai, People's Republic of China.
Meirong
M
Bai
State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, 220 Handan Road, Shanghai, People's Republic of China.
Jun
J
Ni
State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, 220 Handan Road, Shanghai, People's Republic of China.
Suqin
S
Shen
State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, 220 Handan Road, Shanghai, People's Republic of China.
Qiang
Q
Huang
State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, 220 Handan Road, Shanghai, People's Republic of China.
Jiaxue
J
Wu
State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, 220 Handan Road, Shanghai, People's Republic of China.
Yichen
Y
Le
State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, 220 Handan Road, Shanghai, People's Republic of China.
Long
L
Yu
D019943:Amino Acid Substitution; D017209:Apoptosis; D064096:Aurora Kinase A / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018385:Centrosome / Q000378:metabolism; D059565:G2 Phase Cell Cycle Checkpoints; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D060588:LIM Domain Proteins / Q000737:chemistry / Q000378:metabolism*; D059566:M Phase Cell Cycle Checkpoints; D008938:Mitosis; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D008941:Spindle Apparatus / Q000378:metabolism*
C485608:AJUBA protein, human; D060588:LIM Domain Proteins; D064096:Aurora Kinase A