IK-guided PP2A suppresses Aurora B activity in the interphase of tumor cells

• DOI: 10.1007/s00018-016-2162-9
• Publication Date: 2016-02-23T11:13:18Z
• Authors: Sunyi Lee; Ae Lee Jeong; Jeong Su Park; Sora Han; Chang-Young Jang; Keun Il Kim; Yonghwan Kim; Jong Hoon Park; Jong-Seok Lim; Myung Sok Lee; Young Yang
• Keywords: Interphase; Aurora B kinase

Aurora B activation is triggered at the mitotic entry and required for proper microtubule-kinetochore attachment at mitotic phase. Therefore, Aurora B should be in inactive form in interphase to prevent aberrant cell cycle progression. However, it is unclear how the inactivation of Aurora B is sustained during interphase. In this study, we find that IK depletion-induced mitotic arrest leads to G2 arrest by Aurora B inhibition, indicating that IK depletion enhances Aurora B activation before mitotic entry. IK binds to Aurora B, and colocalizes on the nuclear foci during interphase. Our data further show that IK inhibits Aurora B activation through recruiting PP2A into IK and Aurora B complex. It is thus believed that IK, as a scaffold protein, guides PP2A into Aurora B to suppress its activity in interphase until mitotic entry.