Biology subjects

Yu, L.-Y.

Publications and source records attributed to Yu, L.-Y..

5 recordsLinked to original sources

bioRxiv2025

Structure and functional analysis of CDNF-BiP interaction reveal a role in endoplasmic reticulum proteostasis regulation

Cerebral dopamine neurotrophic factor (CDNF) was identified for ability to rescue midbrain dopamine neurons and as endoplasmic reticulum (ER)-located protein that can be secreted. Structurally homologous to mesencephalic astrocyte-derived neurotrophic factor (MANF), CDNF has been shown to interact with ER-localized chaperone BiP. The ER plays a crucial role in protein synthesis, folding, and quality control, with BiP being a key player in maintaining protein homeostasis. CDNF is protective against ER stress and involved in regulating the unfolded protein response (UPR) signaling and interaction with BiP. Recent studies have shown that CDNF interacts with UPR sensor proteins PERK, IRE1, and ATF6, suggesting an overlap in CDNF binding with UPR sensors and BiP. In rodent models of Parkinsons disease (PD), CDNF protects and restores the function of brain dopamine neurons and was successful in PD phase 1 clinical studies. CDNF has shown therapeutic potential for several neurological diseases, including amyotrophic lateral sclerosis, and ischemic stroke. Despite extensive knowledge on CDNFs impact on cellular function and neuronal degeneration, its detailed molecular mechanism of action in the ER remains unclear. Here, we have characterized the CDNF interaction with BiP both structurally and functionally and solved the crystal structures of CDNF-BiP complexes to 1.5 [A] resolution, complemented with molecular dynamics simulations. Results show CDNFs role as an antagonist of BiP nucleotide exchange, and thus in its chaperone function, binding to the ADP-bound state. Finally, we show its effect on neuroprotection with stem cell-derived human dopamine neurons, highlighting its potential in neurodegenerative disease treatment.

biochemistry↗

bioRxiv2024

CDNF rescues human iPSCs-derived dopamine neurons through direct binding to unfolded protein response sensors PERK and IRE1α

Cerebral dopamine neurotrophic factor (CDNF) is an unconventional trophic factor that protects dopamine neurons in cellular and animal models of Parkinsons disease (PD). CDNF was safe and well tolerated in phase 1 clinical trials for PD treatment, and currently, its peptide analogue is under investigation in phase 1 clinical trials for PD. Despite prominent neuroprotective and neurorestorative activity, the receptors and exact mechanism of CDNF functioning have been obscure. Intracellularly acting CDNF exerts cytoprotection by attenuating endoplasmic reticulum (ER) stress and unfolded protein response (UPR). We demonstrated that this activity occurs through the direct binding of CDNF to ER transmembrane UPR sensors PERK and IRE1 for purified proteins and in cells. We identified CDNF mutants deficient for binding to UPR sensors. CDNF binding to PERK and IRE1 appeared to be crucial for the survival of mouse dopamine neurons in culture. Importantly for clinical translation, CDNF rescues human induced pluripotent stem cell-derived dopamine neurons and promotes their regeneration. CDNF binding to UPR sensors alleviated terminal UPR and promoted neurite outgrowth of human dopamine neurons through direct binding to PERK and IRE1. CDNF binding to BiP was dispensable for the neuroprotective and neurorestorative activity of CDNF. Therefore, CDNF, or small molecules mimicking its binding to UPR sensors and acting selectively on dopamine neurons with activated UPR, are promising drug candidates for PD treatment.

neuroscience↗

bioRxiv2023

Small molecule activation of m6A mRNA methylation as a novel approach for neuroprotection

N6-Methyladenosine (m6A) is the most common mRNA base modification in eukaryotes. Methylation of adenosine residues to m6A contributes to the regulation of splicing, transport, stability, and translation of mRNA and two main classes of enzymes regulate it. The formation of m6A is catalysed by a methyltransferase complex containing methyltransferase-like 3 (METTL3), METTL14, and Wilms tumour 1-associated protein (WTAP) as well as monomeric METTL16. Demethylation of m6A is catalysed by the fat mass and obesity-associated protein FTO and the RNA demethylase AlkB homolog 5 (ALKBH5). The m6A mRNA methylation dysregulation occurs in the nervous system and in Parkinsons disease (PD), but it remains poorly studied. Moreover, the role of m6A mRNA methylation in neuronal survival, neuroprotection, and neuroregeneration is unclear. We have earlier used high-throughput virtual screening of large compound libraries and identified four unique small-molecule ligands that activate m6A mRNA methylation by binding to the METTL3/14/WTAP complex and enhancing the binding of the methylation substrate SAM to nanomolar concentrations. Following this, we now discovered that two methyltransferase activators at 10 nM concentrations supported the survival and protected dopamine (DA) neurons in culture in growth factor deprivation and 6-hydroxydopamine (6-OHDA) neurotoxin models. In contrast, METTL3/14 inhibitor STM2457 triggered death of DA neurons. For clinical translation we also tested the most efficient compound C4 on induced pluripotent stem cell-derived human DA neurons and in animal model of Parkinsons disease (PD). C4 compound protected human DA neurons from 6-OHDA-induced cell death and increased neurite outgrowth and the number of processes demonstrating that it has both neuroprotective and neurorestorative properties. METTL3/14 activator C4 improved motor behaviour and protected DA neurons and their fibres faster and much more efficiently than GDNF in the rat 6-OHDA model of PD. These are the first specific activators of METTL3/14/WTAP and first demonstration that m6A regulators can protect and regenerate neurons. These data demonstrate that m6A mRNA methylation is a novel pathway regulating neuronal survival and regeneration.

neuroscience↗

bioRxiv2021

Synthetic dysmobility screen unveils an integrated STK40-YAP-MAPK system driving cell migration

Integrating signals is essential for cell survival, leading to the concept of synthetic lethality. However, how signaling is integrated to control cell migration remains unclear. By conducting a "two-hit" screen, we revealed the synergistic reduction of cell migration when serine-threonine kinase 40 (STK40) and mitogen-activated protein kinase (MAPK) were simultaneously suppressed. Single-cell analyses showed that STK40 knockdown reduced cell motility and coordination by strengthening focal adhesion (FA) complexes. Furthermore, STK40 knockdown reduced translocation of yes-associated protein (YAP) into the nucleus, while MAPK inhibition further weakened YAP activities in the nucleus to disturb FA remodeling. Altogether, we unveiled an integrated STK40-YAP-MAPK system regulating cell migration, and introduced "synthetic dysmobility" as a novel strategy to collaboratively control cell migration. One Sentence SummaryBlocking collaborative pathways within the integrated signaling network synergistically disrupts the migration of cells.

cell biology↗

bioRxiv2020

MANF regulates unfolded protein response and neuronal survival through its ER-located receptor IRE1α

Mesencephalic astrocyte-derived neurotrophic factor (MANF) is an endoplasmic reticulum (ER)-located protein with cytoprotective effects in numerous cell types in vitro and in models of neurodegeneration and diabetes in vivo. So far, the exact mode of its action has remained elusive and plasma membrane or ER-located receptors of MANF have not been identified. We have found that MANF can directly interact with transmembrane unfolded protein response (UPR) receptor IRE1 and compete with the major ER chaperone BiP (GRP78) for the interaction with IRE1. With lower affinities MANF can also interact with other UPR receptors, PERK and ATF6. Using molecular modeling and mutagenesis analysis, we have identified the exact structural MANF regions involved in its binding to the luminal domain of IRE1. MANF attenuates UPR signaling by decreasing IRE1 oligomerization and IRE1 phosphorylation. MANF mutant deficient in IRE1 binding cannot regulate IRE1 oligomerization and fails to protect neurons from ER stress induced death. Importantly, we found that MANF-IRE1 interaction is also crucial for the survival promoting action of MANF for dopamine neurons in an animal model of Parkinsons disease. Our data reveal a novel mechanism of IRE1 regulation during ER stress and demonstrate the intracellular mode of action of MANF as a modulator of UPR and neuronal cell survival through the direct interaction with IRE1 and regulation of its activity. Furthermore, our data explain why MANF in contrast to other growth factors has no effects on naive cells and rescues only ER stressed or injured cells.

cell biology↗