Medicina Molecular e Genética

JAB1/CSN5: A Multifunctional Protein in Cancer

Abstract

Arata Nishimoto, Naruji Kugimiya, Tohru Hosoyama, Tadahiko Enoki, Tao-Sheng Li and Kimikazu Hamano

c-Jun activation domain-binding protein 1 (JAB1) was originally identified as a c-Jun co-activator and subsequently discovered to be a component of the COP9 signalosome (CSN) complex. JAB1, which is also known as CSN5, affects many partner proteins through protein-protein interaction, which leads to protein degradation and transcriptional activation. Thereby, JAB1/CSN5 functions as a multifunctional protein involved in the regulation of cell cycle, signal transduction, and DNA repair. In particular, JAB1/CSN5 plays an essential role in tumorigenesis by degrading tumor suppressor proteins and activating oncogenic transcription factors. JAB1/CSN5 overexpression has been observed in various types of cancer, and it has been multifunctionally involved in cancer progression. In this review, we provide an overview of the roles of JAB1/CSN5 in tumorigenesis and summarize recent findings that highlight the novel roles of JAB1/CSN5 in this process