A1 Journal article (refereed)
The cytoprotective protein MANF promotes neuronal survival independently from its role as a GRP78 cofactor (2021)

Eesmaa, A., Yu, L.-Y., Göös, H., Nõges, K., Kovaleva, V., Hellman, M., Zimmermann, R., Jung, M., Permi, P., Varjosalo, M., Lindholm, P., & Saarma, M. (2021). The cytoprotective protein MANF promotes neuronal survival independently from its role as a GRP78 cofactor. Journal of Biological Chemistry, 296, Article 100295. https://doi.org/10.1016/j.jbc.2021.100295

JYU authors or editors

Publication details

All authors or editors: Eesmaa, Ave; Yu, Li-Ying; Göös, Helka; Nõges, Kristofer; Kovaleva, Vera; Hellman, Maarit; Zimmermann, Richard; Jung, Martin; Permi, Perttu; Varjosalo, Markku; et al.

Journal or series: Journal of Biological Chemistry

ISSN: 0021-9258

eISSN: 1067-8816

Publication year: 2021

Volume: 296

Article number: 100295

Publisher: Elsevier

Publication country: United States

Publication language: English

DOI: https://doi.org/10.1016/j.jbc.2021.100295

Publication open access: Openly available

Publication channel open access: Open Access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/74328

Abstract

Mesencephalic astrocyte-derived neurotrophic factor (MANF) is an ER-stress regulated protein exhibiting cytoprotective properties through a poorly understood mechanism in various in vitro and in vivo models of neuronal and non-neuronal damage. Although initially characterized as a secreted neurotrophic factor for midbrain dopamine neurons, MANF has recently gained more interest for its intracellular role in regulating the ER homeostasis, including serving as a cofactor of the chaperone GRP78. We aimed for a better understanding of the neuroprotective mechanisms of MANF. Here we show for the first time that MANF promotes the survival of ER-stressed neurons in vitro as a general unfolded protein response (UPR) regulator, affecting several UPR pathways simultaneously. Interestingly, MANF does not affect naïve neurons. We hypothesize that MANF regulates UPR signaling towards a mode more compatible with neuronal survival. Screening of MANF interacting proteins from two mammalian cell lines revealed a conserved interactome of 15 proteins including several ER chaperones such as GRP78, GRP170, PDIA1 and PDIA6. Further characterization confirmed previously published finding that MANF is a cofactor of GRP78 interacting with its nucleotide binding domain. Using microscale thermophoresis and NMR spectroscopy, we discovered that MANF is an ATP binding protein and that ATP blocks the MANF-GRP78 interaction. Interestingly, functional analysis of the antiapoptotic properties of MANF mutants in cultured neurons revealed divergent roles of MANF as a GRP78 cofactor and as an antiapoptotic regulator of UPR. We conclude that the co-factor type interaction with GRP78 is dispensable for the survival-promoting activity of MANF in neurons.

Keywords: proteins; neurons; programmed cell death; adenosine triphosphate

Free keywords: mesencephalic astrocyte-derived neurotrophic factor (MANF); GRP78; unfolded protein response (UPR); endoplasmic reticulum stress (ER stress); dopamine neurons; neuronal cell death; protein-protein interaction; neuroprotection; apoptosis; ATP

Contributing organizations

Ministry reporting: Yes

Reporting Year: 2021

JUFO rating: 2