Table 1.

Summary of the neuroprotective and/or neurotoxic properties of HDAC proteins. Mechanisms of action were categorized broadly into the following groups: Protein-protein interactions, Post-translational modifications, Non-histone acetylation, Histone-acetylation, Deacetylase-independent. Note: for some studies summarized in the text, specific mechanisms for the individual HDAC proteins were not known, hence are not shown here. N/A, not applicable.

Class	HDAC subtype	Neuroprotective/Neurotoxic	Mechanism	References
I	HDAC1	Neurotoxic	Protein-protein interactions	Bardai et al. (2012) Kim et al. (2010)
		Neurotoxic	Post-translational modifications	Zhu et al. (2017)
		Neurotoxic	Non-histone acetylation	Jacob et al. (2011) Jeong et al. (2009) Lebrun-Julien et al. (2015) Ravikumar et al. (2004)
		Neurotoxic	Histone-acetylation	Jamal et al. (2017)
		Neuroprotective	Non-histone acetylation	Morrison et al. (2006)
		Neuroprotective	Protein-protein interactions	Dobbin et al. (2013) Qiu et al. (2014) Wang et al. (2013)
	HDAC2	Neurotoxic	Histone-acetylation	Contreras et al. (1859) Graff et al. (2012) Guan et al. (2009) Kernochan et al. (2005) Mohseni et al. (2016)
	HDAC3	Neurotoxic	Post-translational modifications	Bardai et al. (2011) Bardai et al. (2013) Schmitt et al. (2014)
		Neurotoxic	Protein-protein interactions	Bardai et al. (2012) Bardai et al. (2013) Duncan et al. (2013) Kawaguchi et al. (1994)
		Neurotoxic	Histone-acetylation	Chou et al. (2011) Jia et al. (2012) Jia et al. (2015) Jia et al. (2016) Thomas et al. 2008 Thomas et al. (2014) Suelves et al. (2017)
	HDAC8	None reported	N/A	N/A
IIa	HDAC4	Neurotoxic	Post-translational modifications	Li et al. (2012) Herrup et al. (2013) Bolger et al. (2005)
		Neuroprotective	Protein-protein interactions	Hageman et al. (2010) Majdzadeh et al. (2008)
	HDAC5	Neuroprotective	Protein-protein interactions	Cho et al. (2013) Cho et al. (2015)
		Neuroprotective	Post-translational modifications	Cho et al. (2012) Cho et al. (2013)
	HDAC7	Neuroprotective	Deacetylase-independent	Ma et al. (2011)
	HDAC9	Neuroprotective	Non-histone acetylation	Morrison et al. (2006)
		Neuroprotective	Protein-protein interactions	Bardai et al. (2012) Zhang et al. (2008)
IIb	HDAC6	Neuroprotective	Non-histone acetylation	Bali et al. (2005) Cook et al. (2014) Kekatpure et al. (2009) Kovacs et al. (2005) Li et al. (2008) Li et al. (2016) Zhang et al. (2007)
	HDAC6	Neuroprotective	Protein-protein interactions	Boyault et al. (2007) Kawaguchi et al. (2003) Pandey et al. (2007)
		Neurotoxic	Non-histone acetylation	Chen et al. (2010) Cook et al. (2014) Dompierre et al. (2007) Kim et al. (2012)
	HDAC10	None reported	N/A	N/A
IV	HDAC11	Neuroprotective	Protein-protein interactions	Joshi et al. (2013)