RT Journal Article
SR Electronic
T1 LIR-dependent LMX1A/LMX1B autophagy crosstalk shapes human midbrain dopaminergic neuronal resilience
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 636712
DO 10.1101/636712
A1 Natalia Jiménez-Moreno
A1 Petros Stathakos
A1 Zuriñe Antón
A1 Deborah K. Shoemark
A1 Richard B. Sessions
A1 Ralph Witzgall
A1 Maeve Caldwell
A1 Jon D. Lane
YR 2019
UL http://biorxiv.org/content/early/2019/05/14/636712.abstract
AB The LIM homeodomain transcription factors LMX1A and LMX1B are essential mediators of midbrain dopaminergic neuronal (mDAN) differentiation and survival. Here we show that LMX1A and LMX1B are autophagy transcription factors in iPSC-derived human mDANs, each contributing to the expression of important autophagy genes including ULK1, ATG7, ATG16L1 and TFEB. Suppression of LMX1A and LMX1B in mDANs reduces basal autophagy, lowers mitochondrial respiration, and elevates mitochondrial ROS levels; meanwhile overexpression protects against rotenone poisoning in mDANs in vitro. Significantly, we show that LMX1A and LMX1B bind to multiple ATG8 proteins via LIR-type interactions, in a manner dependent on subcellular localisation and nutrient status: LMX1B interacts with LC3B in the nucleus under basal conditions via a C-terminal LIR, but binds to cytosolic LC3B and is degraded by autophagy during nutrient starvation, and LIR mutant LMX1B is unable to protect mDANs against rotenone. This establishes an LMX1A/LMX1B-autophagy regulatory nexus that helps explain the protective roles of these transcription factors in the adult midbrain, thus having implications for our understanding of mDAN decline in PD.