Shank (Shank1-3) are master scaffolding that form the structural backbone of the postsynaptic density (PSD) in glutamatergic synapses. Neurons expressing Shank organize NMDA receptor, AMPA receptor, and mGluR signaling complexes, making them critical for synaptic function, plasticity, and neurodevelopmental/neurodegenerative disease pathogenesis.
| Property | Value |
|---|---|
| Location | Postsynaptic density of glutamatergic synapses |
| Protein Family | SHANK1, SHANK2, SHANK3 |
| Expression | Cortex, hippocampus, striatum, cerebellum |
| Primary Function | PSD scaffold, receptor clustering, spine morphogenesis |
| Disease Relevance | Autism, Phelan-McDermid syndrome, schizophrenia, Alzheimer's disease |
SHANK1 is predominantly expressed in the cerebral cortex and hippocampus: [^1]
SHANK2 (also known as ProSAP1) has diverse roles in synaptic development: [1]
SHANK3 (ProSAP2) is the predominant isoform in striatum and the most clinically significant: [2]
Each Shank protein contains five conserved domains: [3]
| Domain | Position | Binding Partners | Function |
|---|---|---|---|
| ANK repeats | N-terminal | α-fodrin, Sharpin | Membrane anchoring |
| SH3 domain | Central | Abp1, Grb2 | Signaling scaffold |
| PDZ domain | Central | GKAP/SAPAP, ZIP | Scaffold assembly |
| Proline-rich region | C-terminal | Cortactin, Homer | Actin linking |
| SAM domain | C-terminal | Self-association | Shank multimerization |
Shank serve as the central hub of the PSD:
Shank gene mutations are among the most replicated genetic findings in autism: [4]
| Gene | Mutation Type | Clinical Features |
|---|---|---|
| SHANK1 | Point mutations, deletions | High-functioning autism, enhanced memory |
| SHANK2 | De novo truncating, missense | ASD with intellectual disability, seizures |
| SHANK3 | Deletions (22q13), truncating | Phelan-McDermid syndrome, severe ID, absent speech |
Mechanisms of synaptic dysfunction:
22q13.3 deletion syndrome results in complete SHANK3 haploinsufficiency: [5]
SHANK variants contribute to schizophrenia risk: [6]
Shank protein alterations occur in AD: [7]
Mechanisms:
Striatal Shank3 expression is affected in HD:
Berkel S, Marshall CR, Weiss B, et al. Mutations in the SHANK2 synaptic scaffolding gene in autism spectrum disorder and mental retardation. Nature Genetics. 2010;42(6):489-491. 10.1038/ng.589. 2010. ↩︎
Durand CM, Betancur C, Boeckers TM, et al. Mutations in the gene encoding the synaptic scaffolding protein SHANK3 are associated with autism spectrum disorders. Nature Genetics. 2007;39(1):25-27. 10.1038/ng1933. 2007. ↩︎
Baron MK, Boeckers TM, Vaida B, et al. An architectural framework that may lie at the core of the postsynaptic density. Science. 2006;311(5760):531-535. 10.1126/science.1118995. 2006. ↩︎
Leblond CS, Nava C, Polge A, et al. Meta-analysis of SHANK Mutations in Autism Spectrum Disorders: a gradient of severity in cognitive impairments. PLoS Genetics. 2014;10(9):e1004580. 10.1371/journal.pgen.1004580. 2014. ↩︎
Phelan K, McDermid HE. The 22q13.3 Deletion Syndrome (Phelan-McDermid Syndrome). Molecular Syndromology. 2012;2(3-5):186-201. https://pubmed.ncbi.nlm.nih.gov/22904362/. 2012. ↩︎
Gauthier J, Champagne N, Lafrenière RG, et al. De novo mutations in the gene encoding the synaptic scaffolding protein SHANK3 in patients with schizophrenia. Molecular Psychiatry. 2010;15(3):309-312. 10.1038/mp.2009.71. 2010. ↩︎
Roselli F, Hutzler P, Weyer S, et al. Early deficit of synaptic in the spine and postsynaptic density caused by amyloid-beta oligomers. BMC Neuroscience. 2009;10:138. 10.1186/1471-2202-10-138. 2009. ↩︎