Emergingroles of the CIP2A-TopBP1 complex in genome integrity

Abstract

CIP2A is an inhibitor of the tumour suppressor protein phosphatase 2A. R ecently, CIP2A w as identified as a synthetic lethal interactor of BRCA1 and BRCA2 and a driver of basal-like breast cancers. In addition, a joint role of TopBP1 ( topoisomerase II β-binding protein 1 ) and CIP2A for maint aining genome integrit y during mitosis w as disco v ered. TopBP1 has multiple functions as it is a scaff old f or proteins in v olv ed in DNA replication, transcriptional regulation, cell cy cle regulation and DNA repair. Here, w e briefly re vie w details of the CIP2A-TopBP1 interaction, its role in maintaining genome integrity, its in v olv ement in cancer and its potential as a therapeutic target.