Thyroid hormone induction of mitochondrial activity is coupled to mitophagy via ROS-AMPK-ULK1 signaling.

Published

Journal Article

Currently, there is limited understanding about hormonal regulation of mitochondrial turnover. Thyroid hormone (T3) increases oxidative phosphorylation (OXPHOS), which generates reactive oxygen species (ROS) that damage mitochondria. However, the mechanism for maintenance of mitochondrial activity and quality control by this hormone is not known. Here, we used both in vitro and in vivo hepatic cell models to demonstrate that induction of mitophagy by T3 is coupled to oxidative phosphorylation and ROS production. We show that T3 induction of ROS activates CAMKK2 (calcium/calmodulin-dependent protein kinase kinase 2, β) mediated phosphorylation of PRKAA1/AMPK (5' AMP-activated protein kinase), which in turn phosphorylates ULK1 (unc-51 like autophagy activating kinase 1) leading to its mitochondrial recruitment and initiation of mitophagy. Furthermore, loss of ULK1 in T3-treated cells impairs both mitophagy as well as OXPHOS without affecting T3 induced general autophagy/lipophagy. These findings demonstrate a novel ROS-AMPK-ULK1 mechanism that couples T3-induced mitochondrial turnover with activity, wherein mitophagy is necessary not only for removing damaged mitochondria but also for sustaining efficient OXPHOS.

Full Text

Duke Authors

Cited Authors

  • Sinha, RA; Singh, BK; Zhou, J; Wu, Y; Farah, BL; Ohba, K; Lesmana, R; Gooding, J; Bay, B-H; Yen, PM

Published Date

  • 2015

Published In

Volume / Issue

  • 11 / 8

Start / End Page

  • 1341 - 1357

PubMed ID

  • 26103054

Pubmed Central ID

  • 26103054

Electronic International Standard Serial Number (EISSN)

  • 1554-8635

Digital Object Identifier (DOI)

  • 10.1080/15548627.2015.1061849

Language

  • eng

Conference Location

  • United States