Aurora kinase A (AURKA, also known as Aurora 2) is a mitotic serine/threonine kinase that contributes to the regulation of cell cycle progression. It associates with the centrosome and the spindle microtubules during mitosis and plays a critical role in regulating centrosome maturation and separation and bipolar spindle assembly [, ]. It also plays an important role in the spindle checkpoint regulation []. Aurora A promotes mitotic entry by controlling activation of Cyclin-B/Cdk-1. It regulates the progression of mitosis by phosphorylation of multiple substrates, such as Polo-like kinase-1, ajuba, enhancer of filamentation 1, BORA, TPX2, PLK-1, astrin, growth arrest and DNA damage-inducible 45alpha, transforming acidic coiled-coil containing protein 3 (TACC3) and centrosomin []. During mitotic exit, AURKA is targeted for degradation through its interaction with the multi-subunit E3-ubiquitin ligase anaphase promoting complex/cyclosome (APC/C) [].The Aurora kinases are highly conserved serine/threonine kinases that regulate chromosomal alignment and segregation during mitosis and meiosis. Three mammalian Aurora kinases, Aurora A, B and C, have been identified. They all contain a protein kinase domain and a destruction box (D-box) recognised by the multi-subunit E3-ubiquitin ligase anaphase promoting complex/cyclosome (APC/C), which mediates their proteasomal degradation. However, their N-terminal domain share little sequence identity and confer unique protein-protein interaction abilities among the Aurora kinases []. They are differentially expressed at high levels in rapidly dividing tissues such as hematopoietic cells (A and B) andgerm cells (C only). Their expression is low or absent in most adult tissues due to their lower rates of proliferation [].
Aurora kinase A and ninein-interacting protein (also known as AIBp or AUNIP) is a family of eukaryotic proteins necessary for the adequate functioning of Aurora-A, a protein involved in chromosome alignment, centrosome maturation, mitotic spindle assembly and aspects oftumourigenesis. AIBp is likely to act as a regulator of Aurora-A activity []. It interacts with with AURKA via its C terminus and interacts with NIN via its N terminus [].
This entry represents the C-terminal domain of protein furry (Fry). Fry plays a crucial role in the structural integrity of mitotic centrosomes and in the maintenance of spindle bipolarity. This domain binds to polo-like kinase 1 (Plk1) through the polo-box domain (PBD) of Plk1 in a manner dependent on the cyclin-dependent kinase 1-mediated Fry phosphorylation, promoting Plk1 activity during early mitosis. Fry also binds to Aurora A and may function as a scaffold promoting the interaction between AURKA and PLK1, thereby enhancing AURKA-mediated PLK1 phosphorylation [].
