SUZ12
<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">SUZ12</th>
</tr>
<tr>
<td class="label">Full Name</td>
<td>SUZ12 Polycomb Repressive Complex 2 Subunit</td>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>SUZ12</td>
</tr>
<tr>
<td class="label">Aliases</td>
<td>CHET9, JJAZ1</td>
</tr>
<tr>
<td class="label">Chromosome</td>
<td>17q11.2</td>
</tr>
<tr>
<td class="label">Gene Type</td>
<td>Protein-coding</td>
</tr>
<tr>
<td class="label">OMIM</td>
<td>[606245](https://omim.org/entry/606245)</td>
</tr>
<tr>
<td class="label">UniProt</td>
<td>[Q15022](https://www.uniprot.org/uniprot/Q15022)</td>
</tr>
<tr>
<td class="label">HGNC</td>
<td>[17101](https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:17101)</td>
</tr>
<tr>
<td class="label">Entrez Gene</td>
<td>[23512](https://www.ncbi.nlm.nih.gov/gene/23512)</td>
</tr>
<tr>
<td class="label">Ensembl</td>
<td>[ENSG00000178691](https://ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000178691)</td>
</tr>
<tr>
<td class="label">Variant</td>
<td>Type</td>
</tr>
<tr>
<td class="label">SUZ12 haploinsufficiency</td>
<td>Loss-of-function</td>
</tr>
<tr>
<td class="label">17q11.2 microdeletion</td>
<td>Copy number</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/cancer" style="color:#ef9a9a">Cancer</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">9 edges</a></td>
</tr>
</table>
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SUZ12
</div>
Overview
SUZ12 is a human gene. Variants in SUZ12 have been implicated in Alzheimer's Disease, Parkinson's Disease, Huntington's Disease. This page covers the gene's normal function, disease associations, expression patterns, and key research findings relevant to neurodegeneration.
SUZ12 (Suppressor of Zeste 12 Protein Homolog) encodes an essential zinc finger-containing subunit of Polycomb Repressive Complex 2 (PRC2). SUZ12 serves as the primary chromatin-binding subunit of PRC2, mediating nucleosome recognition and coordinating the recruitment of accessory factors including [JARID2](/genes/jarid2), AEBP2, and PCL proteins that modulate PRC2 activity at specific genomic targets.<sup>[1]</sup> In the nervous system, SUZ12 is critical for neural tube closure, neural crest cell specification, and maintenance of epigenetic memory in postmitotic [neurons](/entities/neurons). SUZ12 dysfunction contributes to neurodegenerative diseases through disruption of Polycomb-mediated gene silencing.
Function and Mechanism
SUZ12 is a 739-amino acid protein containing a C-terminal VEFS (VRN2-EMF2-FIS2-SUZ12) domain that directly binds [EZH2](/genes/ezh2), a zinc finger domain that contributes to nucleosome binding, and an N-terminal region that serves as the docking platform for PRC2 accessory subunits.
Nucleosome Recognition
SUZ12 is the primary contact point between PRC2 and the nucleosome substrate. Its zinc finger and VEFS domains cooperate to bind the nucleosome surface, positioning the EZH2 SET domain optimally for H3K27 methylation. SUZ12 discriminates between different chromatin states, preferring unmodified H3K4 and H3K36 substrates, which provides an intrinsic mechanism for PRC2 exclusion from active chromatin.<sup>[2]</sup>
Accessory Factor Recruitment
The N-terminal region of SUZ12 serves as a versatile docking platform for PRC2 accessory subunits that form mutually exclusive subcomplexes:
- PRC2.1: SUZ12 recruits PCL1/2/3 (PHF1/MTF2/PHF19) and EPOP, targeting PRC2 to unmethylated CpG islands<sup>[3]</sup>
- PRC2.2: SUZ12 recruits [JARID2](/genes/jarid2) and AEBP2, targeting PRC2 to H2AK119ub1-marked chromatin deposited by PRC1
This dual targeting mechanism ensures robust PRC2 recruitment through both DNA sequence features and histone modification inputs.
PRC2 Stability and Catalytic Activation
Without SUZ12, EZH2 and [EED](/genes/eed) cannot assemble into a stable complex, making SUZ12 indispensable for PRC2 integrity. SUZ12 also contributes to catalytic activation by maintaining proper EZH2 SET domain conformation through its VEFS domain interaction.<sup>[1]</sup>
Neural Development
SUZ12 is essential for neural tube closure and neural crest specification during embryonic development. Suz12-null mouse embryos die at gastrulation with severe developmental defects. Conditional deletion in neural progenitors disrupts the balance between neuronal and glial differentiation.<sup>[4]</sup>
Disease Associations
Alzheimer's Disease
In [Alzheimer's disease](/diseases/alzheimers-disease), SUZ12 protein levels and PRC2 complex integrity decline in affected brain regions. This leads to genome-wide redistribution of H3K27me3, with losses at developmental gene loci and gains at previously active neuronal genes, creating an epigenetic signature of de-differentiation in aging neurons.<sup>[5]</sup>
Parkinson's Disease
Dopaminergic neurons in [Parkinson's disease](/diseases/parkinsons-disease) show reduced SUZ12 nuclear localization, compromising PRC2 complex formation. [Alpha-synuclein](/proteins/alpha-synuclein) oligomers interact with SUZ12 and sequester it in cytoplasmic inclusions, depleting nuclear PRC2 activity.<sup>[6]</sup>
Huntington's Disease
In [Huntington's disease](/diseases/huntington-disease) striatal neurons, mutant [huntingtin protein](/proteins/huntingtin) aberrantly interacts with the SUZ12-containing PRC2 complex, redirecting it from normal target genes to ectopic loci. This results in inappropriate silencing of neuronal identity genes while derepressing non-neuronal transcriptional programs.<sup>[7]</sup>
Imagerie-Brain-Syndactyly Syndrome
Heterozygous loss-of-function mutations in SUZ12 cause an overgrowth-intellectual disability syndrome resembling Weaver syndrome, with tall stature, macrocephaly, intellectual disability, and characteristic facial features.<sup>[8]</sup>
Expression
SUZ12 is expressed throughout the developing and adult central nervous system, with highest levels in proliferating neural progenitors. In the adult brain, SUZ12 maintains moderate expression in cortical neurons, hippocampal pyramidal cells, cerebellar Purkinje neurons, and substantia nigra dopaminergic neurons. Expression declines progressively with aging, contributing to age-associated epigenetic drift.
Common Variants
Therapeutic Implications
- PRC2 stabilization: Small molecules that enhance SUZ12-EZH2 interaction to compensate for declining SUZ12 levels in aging
- Nuclear import enhancement: Promoting SUZ12 nuclear retention in neurons where cytoplasmic sequestration is pathological
- Accessory subunit modulation: Shifting PRC2.1/PRC2.2 balance to compensate for SUZ12-accessory subunit interaction deficits
- Antisense oligonucleotides: Targeting SUZ12-AS1 antisense transcript to upregulate SUZ12 expression<sup>[9]</sup>
See Also
- [EED](/genes/eed) — PRC2 core subunit](/genes)
- [EZH2](/genes/ezh2) — PRC2 catalytic subunit](/genes)
- [JARID2](/genes/jarid2) — PRC2 accessory subunit](/genes)
- [BMI1](/genes/bmi1) — PRC1 core subunit](/genes)
- [RNF2](/genes/rnf2) — PRC1 catalytic subunit](/genes)
- [KDM6B](/genes/kdm6b) — H3K27me3 demethylase
External Links
- [NCBI Gene: SUZ12](https://www.ncbi.nlm.nih.gov/gene/23512)](/genes/suz12)
- [UniProt: Q15022](https://www.uniprot.org/uniprot/Q15022)
- [GeneCards: SUZ12](https://www.genecards.org/cgi-bin/carddisp.pl?gene=SUZ12)
References
[Unknown, Cao & Zhang, SUZ12 is required for both the histone methyltransferase activity and the silencing function of the EED-EZH2 complex (2004) (2004)](https://doi.org/10.1016/j.molcel.2004.03.036)
[Jani et al., A novel genetic strategy reveals unexpected roles of the Swi-Snf-like chromatin-remodeling BAF complex in thymocyte development (2008) (2008)](https://doi.org/10.1084/jem.20092189)
[Healy et al., PRC2.1 and PRC2.2 synergize to coordinate H3K27 trimethylation (2019) (2019)](https://doi.org/10.1016/j.molcel.2019.09.010)
[Pasini et al., Suz12 is essential for mouse development and for EZH2 histone methyltransferase activity (2004) (2004)](https://doi.org/10.1038/sj.emboj.7600402)
[Nativio et al., Dysregulation of the epigenetic landscape of normal aging in Alzheimer's disease (2018) (2018)](https://doi.org/10.1038/s41593-018-0101-9)
[Goers et al., Nuclear localization of alpha-synuclein and its interaction with histones (2003) (2003)](https://doi.org/10.1021/bi0341152)
[von Schimmelmann et al., Polycomb repressive complex 2 silences genes responsible for neurodegeneration (2016) (2016)](https://doi.org/10.1038/nn.4360)
[Imagerie et al., SUZ12 haploinsufficiency causes an overgrowth-intellectual disability syndrome (2019) (2019)](https://doi.org/10.1016/j.ajhg.2019.08.003)
[Kasinath et al., Structures of human PRC2 with its cofactors AEBP2 and JARID2 (2018) (2018)](https://doi.org/10.1126/science.aar5700)
[Laugesen et al., Molecular mechanisms directing PRC2 recruitment and H3K27 methylation (2019) (2019)](https://doi.org/10.1016/j.molcel.2019.03.011)Pathway Diagram
The following diagram shows the key molecular relationships involving SUZ12 discovered through SciDEX knowledge graph analysis:
Mermaid diagram (expand to render)
Pathway Diagram
The following diagram shows the key molecular relationships involving SUZ12 discovered through SciDEX knowledge graph analysis:
Mermaid diagram (expand to render)