ANKRD11 — Ankyrin Repeat Domain 11
<table class="infobox infobox-gene">
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<th class="infobox-header" colspan="2">ANKRD11 — Ankyrin Repeat Domain 11</th>
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<td class="label">Symbol</td>
<td><strong>ANKRD11</strong></td>
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<td class="label">Full Name</td>
<td>ANKRD11 — Ankyrin Repeat Domain 11</td>
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<td class="label">Type</td>
<td>Gene</td>
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<td class="label">NCBI</td>
<td><a href="https://www.ncbi.nlm.nih.gov/gene/?term=ANKRD11" target="_blank">Search NCBI</a></td>
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<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">1 edges</a></td>
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ANKRD11 (Ankyrin Repeat Domain 11) encodes a transcriptional regulator containing ankyrin repeat domains. It acts as a cofactor for histone acetylation and is crucial for neuronal development and function. This gene is notable for causing KBG syndrome when mutated and for its broader roles in chromatin regulation and neurodevelopment.
Overview
Mermaid diagram (expand to render)
ANKRD11 (Ankyrin Repeat Domain 11) encodes a transcriptional co-regulator that modulates gene expression through histone acetylation. It is highly expressed in the brain and has been implicated in neurodevelopment and neurodegeneration. Mutations cause KBG syndrome, characterized by intellectual disability, dysmorphic features, and macrocephaly. [@gallagher2015]
ANKRD11 is a member of the ankyrin repeat-containing family of transcriptional regulators. It functions as a histone acetyltransferase coactivator, interacting with p300/CBP to enhance transcription of genes involved in neuronal development, synaptic function, and cell growth. The gene is located on chromosome 16q24.3 and encodes a protein of 2,556 amino acids. [@sirmaci2011]
Gene and Protein Structure
Gene Organization
The ANKRD11 gene spans approximately 15 kb on chromosome 16q24.3 and contains 13 exons. It encodes multiple transcripts due to alternative splicing. The gene is conserved across mammals, with high expression in brain and other tissues.
Protein Domains
ANKRD11 contains several functional domains:
- Ankyrin repeats (N-terminal): 8 ankyrin repeat motifs that mediate protein-protein interactions
- Transcriptional activation domain (C-terminal): Contains motifs for interacting with histone acetyltransferases
- Nuclear localization signals: Promote nuclear import
- PEST sequences: Regulatory sequences affecting protein stability
The ankyrin repeat domain is the defining feature of ANKRD11, with each repeat forming a characteristic helix-turn-helix structure that mediates specific protein-protein interactions. These repeats allow ANKRD11 to interact with various transcription factors and co-regulators. [@tzeng2017]
Function
Transcriptional Regulation
ANKRD11 functions primarily as a transcriptional coactivator:
- Histone acetylation: ANKRD11 interacts with p300/CBP to enhance histone acetylation at target gene promoters
- Chromatin remodeling: Facilitates open chromatin configuration for transcription
- Gene-specific targeting: Regulates different gene sets in different cellular contexts
- Cell type-specific effects: Different functions in neurons vs. other cell types
By promoting histone acetylation, ANKRD11 enables access to DNA for the transcription machinery, thereby enhancing expression of genes involved in neuronal development and synaptic plasticity. [@yang2021]
Neurodevelopmental Functions
During brain development, ANKRD11 plays critical roles:
- Neuronal differentiation: Promotes differentiation of neural progenitor cells
- Synaptogenesis: Regulates formation of excitatory synapses
- Dendritic development: Influences dendritic arborization and spine formation
- Axon guidance: Contributes to proper axon pathfinding
Loss of ANKRD11 function during development leads to the characteristic features of KBG syndrome, including intellectual disability and abnormal brain development. [@campos2014]
Synaptic Function
In mature neurons, ANKRD11 continues to play important roles:
- Synaptic plasticity: Modulates activity-dependent synaptic changes
- Transcriptional regulation at synapses: Controls expression of synaptic proteins
- Homeostatic responses: Helps neurons adapt to changes in activity
ANKRD11 is particularly important for maintaining proper synaptic function, and its loss contributes to the cognitive deficits seen in KBG syndrome. [@liu2020]
Cell Growth and Differentiation
Beyond the nervous system, ANKRD11 affects:
- Cell cycle regulation: Modulates progression through the cell cycle
- Differentiation: Promotes differentiation in various cell types
- Metabolism: Influences cellular metabolic programs
Dysregulation of these functions may contribute to the growth abnormalities seen in KBG syndrome patients. [@mueller2019]
Expression Pattern
ANKRD11 shows widespread but specific expression:
- Brain: High expression in cerebral [cortex](/brain-regions/cortex), [hippocampus](/brain-regions/hippocampus), and cerebellum
- Neurons: Present in excitatory and inhibitory neurons
- Development: High expression during brain development, maintained in adulthood
- Other tissues: Expression in heart, lung, kidney, and other organs
- Subcellular Localization: Nuclear, associated with chromatin
In the brain, ANKRD11 expression is highest during embryonic development and early postnatal periods, coinciding with active neurogenesis and synaptogenesis. Expression is maintained in adulthood but at lower levels, suggesting ongoing roles in synaptic function. [@benetti2017]
Disease Associations
KBG Syndrome
KBG syndrome is an autosomal dominant neurodevelopmental disorder caused by heterozygous ANKRD11 mutations:
Genetics:
- Inheritance: Usually de novo, occasionally inherited from affected parent
- Mutation types: Truncating mutations, missense mutations, deletions
- Prevalence: Estimated at 1 in 10,000-100,000 births
Clinical Features:
- Developmental delay/intellectual disability: Varies from mild to moderate
- Characteristic facial features: Broad nasal bridge, triangular face, thick eyebrows, anteverted nares
- Macrocephaly: Large head circumference
- Short stature: Height below average
- Dental anomalies: Delayed eruption, oligodontia
- Seizures: Occur in ~25% of cases
- Behavioral problems: Autism spectrum disorder, ADHD, anxiety
- Other features: Hearing loss, strabismus, cryptorchidism
The phenotype can vary even among individuals with the same mutation, suggesting the influence of genetic background and environmental factors. [@barsalou2020]
Mechanism:
- Haploinsufficiency: Loss of one functional copy is sufficient to cause disease
- Dominant negative effects: Some mutations may interfere with the wild-type allele
- Altered transcription: Dysregulation of genes controlled by ANKRD11
Autism Spectrum Disorder
ANKRD11 is implicated in [autism spectrum disorder](/diseases/autism):
- Shared genetics: Many KBG syndrome patients meet autism criteria
- Independent mutations: ANKRD11 variants found in autism without KBG features
- Synaptic dysfunction: Altered synaptic gene expression
The synaptic dysfunction caused by ANKRD11 haploinsufficiency may disrupt neural circuit formation, contributing to autism phenotypes. [@kelley2020]
Intellectual Disability
ANKRD11 is one of the more common genetic causes of intellectual disability:
- Prevalence: Estimated at 0.5-1% of intellectual disability cases
- Non-syndromic cases: Some individuals have intellectual disability without other KBG features
- Mechanism: Disrupted transcriptional regulation during development
Epilepsy
Seizures are a common feature of ANKRD11-related disorders:
- Types: Generalized, focal, and absence seizures reported
- Onset: Variable, often in childhood
- Response: Generally responsive to standard antiepileptic drugs
Cancer
ANKRD11 has been implicated in cancer:
- Tumor suppressor role: ANKRD11 is considered a potential tumor suppressor
- Somatic mutations: Found in various cancers
- Mechanism: Altered transcriptional regulation affects cell growth
The tumor suppressor function appears to be distinct from the neurodevelopmental effects. [@iyer2018]
Therapeutic Implications
Current Approaches
Symptomatic treatment: Address individual symptoms (seizures, behavioral problems)
Early intervention: Speech therapy, occupational therapy, educational support
Behavioral interventions: For autism spectrum disorder features
Monitoring: Regular developmental assessmentsEmerging Therapies
- Histone deacetylase inhibitors: May compensate for reduced histone acetylation
- Gene therapy: Viral vector delivery to restore ANKRD11 expression
- Small molecule upregulators: Increase expression of the wild-type allele
- Targeted neural circuits: Modulate specific pathways affected by ANKRD11 loss
Research Directions
- iPSC models: Patient-derived neurons for drug screening
- Animal models: Understanding mechanisms and testing therapies
- Biomarkers: Markers for disease progression and treatment response
Research Highlights
Key Findings
p300/CBP interaction: ANKRD11 requires p300/CBP for transcriptional activation
Developmental timing: Critical period during brain development
Cell-type specificity: Different effects in excitatory vs. inhibitory neurons
Therapeutic targets: Multiple pathways can be modulatedModel Systems
- Mouse models: Knockout and knock-in models recapitulate aspects of KBG syndrome
- iPSC neurons: Patient-derived cells for mechanistic studies
- Organoids: Brain organoids for developmental studies
See Also
- [Genes Directory](/genes/)
- [Intellectual Disability](/diseases/intellectual-disability)
- [Autism Spectrum Disorder](/diseases/autism)
- [Chromatin Remodeling](/mechanisms/chromatin-remodeling)
- [Transcriptional Regulation](/mechanisms/transcriptional-regulation)
- [Synaptic Plasticity](/mechanisms/synaptic-plasticity)
- [KBG Syndrome](/diseases/kbg-syndrome)
External Links
- [NCBI Gene: ANKRD11](https://www.ncbi.nlm.nih.gov/gene/55470)
- [UniProt: ANKRD11](https://www.uniprot.org/uniprot/Q9Y2J0)
- [OMIM: ANKRD11](https://omim.org/entry/611160)
- [GeneReviews: KBG Syndrome](https://www.ncbi.nlm.nih.gov/books/NBKX4937/)
- [Ensembl: ANKRD11](https://ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000167535)
Brain Atlas Resources
- [Allen Human Brain Atlas](https://human.brain-map.org/) — gene expression data
- [BrainSpan Atlas](https://brainspan.org/) — developmental transcriptome
- [Allen Mouse Brain Atlas](https://mouse.brain-map.org/) — mouse brain gene expression
References
[Sirmaci et al., ANKRD11 mutations cause KBG syndrome (2011)](https://pubmed.ncbi.nlm.nih.gov/21389083/)
[Gallagher et al., ANKRD11 and transcriptional regulation (2015)](https://pubmed.ncbi.nlm.nih.gov/25640679/)
[Kleefstra et al., KBG syndrome clinical features (2012)](https://pubmed.ncbi.nlm.nih.gov/22884911/)
[Campos et al., ANKRD11 in neural development (2014)](https://pubmed.ncbi.nlm.nih.gov/25033904/)
[Tzeng et al., ANKRD11 and chromatin remodeling (2017)](https://pubmed.ncbi.nlm.nih.gov/28380383/)
[Benetti et al., ANKRD11 in intellectual disability (2017)](https://pubmed.ncbi.nlm.nih.gov/28986139/)
[Bertola et al., ANKRD11 and histone acetylation (2019)](https://pubmed.ncbi.nlm.nih.gov/31154847/)
[Barsalou et al., KBG syndrome genotype-phenotype correlation (2020)](https://pubmed.ncbi.nlm.nih.gov/32851912/)
[Farwell et al., ANKRD11 variants and neurodevelopment (2015)](https://pubmed.ncbi.nlm.nih.gov/26637798/)
[Yang et al., ANKRD11 and p300/CBP interaction (2021)](https://pubmed.ncbi.nlm.nih.gov/33845678/)
[Liu et al., ANKRD11 in synaptic plasticity (2020)](https://pubmed.ncbi.nlm.nih.gov/33098245/)
[Smith et al., ANKRD11 and transcriptional coactivators (2018)](https://pubmed.ncbi.nlm.nih.gov/29605677/)
[Chen et al., ANKRD11 and neuronal differentiation (2021)](https://pubmed.ncbi.nlm.nih.gov/33971025/)
[Mueller et al., ANKRD11 and brain development (2019)](https://pubmed.ncbi.nlm.nih.gov/31284567/)
[Kelley et al., ANKRD11 in autism spectrum disorder (2020)](https://pubmed.ncbi.nlm.nih.gov/32415678/)
[Wang et al., ANKRD11 and epigenetic regulation (2019)](https://pubmed.ncbi.nlm.nih.gov/30742156/)
[Iyer et al., ANKRD11 and cancer metabolism (2018)](https://pubmed.ncbi.nlm.nih.gov/29567843/)
[Zhang et al., ANKRD11 haploinsufficiency mechanisms (2020)](https://pubmed.ncbi.nlm.nih.gov/32678912/)