泛素连接酶
磷酸化
DNA连接酶
泛素
化学
细胞生物学
生物化学
生物
酶
基因
作者
Cory M. Nadel,Kristin Wucherer,Abby Oehler,Aye C. Thwin,Koli Basu,Matthew Callahan,Daniel R. Southworth,Daniel A. Mordes,Charles S. Craik,Jason E. Gestwicki
标识
DOI:10.1101/2023.08.16.553575
摘要
ABSTRACT Microtubule-associated protein tau (MAPT/tau) accumulates in a family of neurodegenerative diseases, including Alzheimer’s disease (AD). In disease, tau is aberrantly modified by post-translational modifications (PTMs), including hyper-phosphorylation. However, it is often unclear which of these PTMs contribute to tau’s accumulation or what mechanisms might be involved. To explore these questions, we focused on a cleaved proteoform of tau (tauC3), which selectively accumulates in AD and was recently shown to be degraded by its direct binding to the E3 ubiquitin ligase, CHIP. Here, we find that phosphorylation of tauC3 at a single residue, pS416, is sufficient to block its interaction with CHIP. A co-crystal structure of CHIP bound to the C-terminus of tauC3 revealed the mechanism of this clash and allowed design of a mutation (CHIP D134A ) that partially restores binding and turnover of pS416 tauC3. We find that pS416 is produced by the known AD-associated kinase, MARK2/Par-1b, providing a potential link to disease. In further support of this idea, an antibody against pS416 co-localizes with tauC3 in degenerative neurons within the hippocampus of AD patients. Together, these studies suggest a discrete molecular mechanism for how phosphorylation at a specific site contributes to accumulation of an important tau proteoform.
科研通智能强力驱动
Strongly Powered by AbleSci AI