Septin1, a new interaction partner for human serine/threonine kinase aurora-B.
Several families of kinases work together to ensure the rate and precision of mitosis. Aurora-B is an important serine/threonine kinase required for chromosome segregation and cytokinesis. Identification of Aurora-B substrates will help to enhance our understanding of the molecular mechanism of mitosis. Through a yeast two-hybrid screen, we found a novel partner of Aurora-B, Septin1, belonging to a conserved family of GTPase proteins that localize to the cleavage furrow and are involved in cytokinesis. We confirmed this interaction using Co-immunoprecipitation experiments in mammalian cells and GST-pull-down analysis in vitro. Moreover, Aurora-B can phosphorylate Septin1 in vitro. We identified that Ser248, Ser307, and Ser315 are the main phosphorylation sites in Septin1. These two proteins partially co-localize to the midbody during cytokinesis. So, it is possible that Septin1's role in the regulation of cytokinesis is related to its phosphorylation by Aurora-B. Unlike previous reports that Septins function in cytokinesis and localize to the cleavage furrow, we found that Septin1 localizes to the spindle pole throughout mitosis, indicating that Septin1 may function in chromosome segregation as well.
Qi
Meiyan
M
State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai 200433, PR China.
Yu
Wenbo
W
Liu
Shen
S
Jia
Huijue
H
Tang
Lisha
L
Shen
Mingjuan
M
Yan
Xiaomei
X
Saiyin
Hexige
H
Lang
Qingyu
Q
Wan
Bo
B
Zhao
Shouyuan
S
Yu
Long
L
D064107:Aurora Kinase B; D064127:Aurora Kinases; D006367:HeLa Cells; D006801:Humans; D010744:Phosphoric Monoester Hydrolases / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D010768:Phosphoserine / Q000032:analysis; D017346:Protein Serine-Threonine Kinases / Q000032:analysis / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
D010768:Phosphoserine; C576921:AURKB protein, human; D064107:Aurora Kinase B; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases; D010744:Phosphoric Monoester Hydrolases