CYFIP2 — Cytoplasmic FMRP Interacting Protein 2
<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">CYFIP2 — Cytoplasmic FMRP Interacting Protein 2</th>
</tr>
<tr>
<td class="label">Symbol</td>
<td><strong>CYFIP2</strong></td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>Cytoplasmic FMRP Interacting Protein 2</td>
</tr>
<tr>
<td class="label">Chromosome</td>
<td>5q33.3</td>
</tr>
<tr>
<td class="label">NCBI Gene</td>
<td><a href="https://www.ncbi.nlm.nih.gov/gene/26999" target="_blank">26999</a></td>
</tr>
<tr>
<td class="label">Ensembl</td>
<td><a href="https://ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000155189" target="_blank">ENSG00000155189</a></td>
</tr>
<tr>
<td class="label">OMIM</td>
<td><a href="https://omim.org/entry/605322" target="_blank">605322</a></td>
</tr>
<tr>
<td class="label">UniProt</td>
<td><a href="https://www.uniprot.org/uniprot/Q9Y2D89" target="_blank">Q9Y2D89</a></td>
</tr>
<tr>
<td class="label">Protein Class</td>
<td>FMRP Interacting Protein family</td>
</tr>
<tr>
<td class="label">Molecular Weight</td>
<td>125 kDa</td>
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<td class="label">Expression</td>
<td>Brain, [Neurons](/entities/neurons), [Cortex](/brain-regions/cortex), [Hippocampus](/brain-regions/hippocampus)</td>
</tr>
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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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</table>
Overview
CYFIP2 (Cytoplasmic FMRP Interacting Protein 2), also known as p155, is a critical neuronal protein that functions as a key regulator of synaptic plasticity, actin cytoskeleton dynamics, and RNA processing[@cyfip2004][@cyfip2018]. The protein is encoded by the CYFIP2 gene located on chromosome 5q33.3 and is highly expressed in the brain, particularly in the cerebral cortex and hippocampus — regions critically involved in learning, memory, and neurodegenerative processes[@cyfip2015].
CYFIP2 was originally identified as an interactor of FMR1 (Fragile X Mental Retardation 1), the gene mutated in Fragile X syndrome, linking it to synaptic dysfunction and neurodevelopmental disorders. However, emerging research has revealed important roles for CYFIP2 in neurodegenerative diseases including Alzheimer's Disease (AD) and Parkinson's Disease (PD)[@cyfip2022].
Structure and Domain Organization
CYFIP2 contains several functional domains that mediate its diverse cellular functions:
- WAVE Regulatory Complex (WRC) binding domain: Mediates interaction with the WAVE complex, regulating actin polymerization
- RAFT domain: Required for interaction with FMRP and other RNA-binding proteins
- HEAT repeats: Structural repeats involved in protein-protein interactions
- N-terminal coiled-coil domain: Facilitates homodimerization and heterodimerization
The protein adopts a horseshoe-like structure that enables simultaneous binding to multiple partners, positioning it as a molecular scaffold coordinating signaling pathways at the synapse.
Normal Function in the Nervous System
CYFIP2 plays multiple essential roles in neuronal physiology:
Synaptic Plasticity Regulation
CYFIP2 is a key modulator of synaptic plasticity — the cellular basis of learning and memory. It regulates both excitatory and inhibitory synaptic transmission through its interactions with FMRP and the WAVE complex[@cyfip2019]. By controlling actin cytoskeleton dynamics at [dendritic spines](/mechanisms/dendritic-spines), CYFIP2 influences spine morphology, size, and stability — all critical parameters for proper synaptic connectivity.
RNA Processing
As an FMRP-interacting protein, CYFIP2 participates in the regulation of mRNA translation at synapses. This function is particularly important for local protein synthesis required during [long-term potentiation](/mechanisms/long-term-potentiation) (LTP) and long-term depression (LTD), forms of synaptic plasticity underlying learning and memory[@fmrp2020].
Neuronal Development
During brain development, CYFIP2 regulates neuronal migration, axon guidance, and dendrite morphogenesis through its effects on the actin cytoskeleton. The protein ensures proper formation of neuronal circuits and maintains synaptic integrity throughout life.
Role in Neurodegenerative Diseases
Alzheimer's Disease (AD)
Dysregulation of CYFIP2 has been implicated in AD pathogenesis:
Synaptic loss: CYFIP2 expression is altered in AD brain, contributing to synaptic dysfunction characteristic of the disease[@cyfip2021]
Amyloid-β toxicity: Studies show that [Aβ](/proteins/amyloid-beta) oligomers affect CYFIP2 localization and function in neurons
Tau pathology: CYFIP2 interacts with [tau protein](/proteins/tau) and may influence tau-induced neurodegeneration
Redox imbalance: Oxidative stress in AD affects CYFIP2 post-translational modificationsParkinson's Disease (PD)
Emerging evidence links CYFIP2 to PD:
α-Synuclein interaction: CYFIP2 may interact with [alpha-synuclein](/proteins/alpha-synuclein) and influence its aggregation
Mitochondrial function: CYFIP2 regulates mitochondrial dynamics relevant to PD pathogenesis
Dopaminergic neuron survival: The protein supports viability of dopaminergic neurons, which degenerate in PDOther Neurodegenerative Conditions
- Fragile X Syndrome: CYFIP2 dysfunction contributes to intellectual disability and autism
- Intellectual Disability: De novo CYFIP2 mutations cause severe neurodevelopmental disorders
- Amyotrophic Lateral Sclerosis (ALS): Altered CYFIP2 expression observed in motor neurons
Therapeutic Implications
CYFIP2 represents a potential therapeutic target for neurodegenerative diseases:
- Synaptic protection: Enhancing CYFIP2 function may protect synapses from degeneration
- Modulating actin dynamics: Targeting CYFIP2-WAVE interactions could improve synaptic plasticity
- FMRP pathway: Restoring CYFIP2-FMRP signaling may benefit memory function
Cross-links
- [CYFIP2 Gene](/genes/cyfip2)
- [FMRP Protein](/proteins/fmrp-protein)
- [Synaptic Plasticity](/mechanisms/synaptic-plasticity)
- [Alzheimer's Disease](/diseases/alzheimers-disease)
- [Parkinson's Disease](/diseases/parkinsons-disease)
See Also
- [ Protein](/proteins/amyloid-beta)
- [Synaptic Plasticity](/mechanisms/synaptic-plasticity)
- [Alzheimer's Disease](/diseases/alzheimers-disease)
- [Parkinson's Disease](/diseases/parkinsons-disease)
External Links
- [Ensembl: ENSG00000155189](https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000155189)
References
[Unknown, CYFIP2, a new neuronal partner of FMRP (2004) (2004)](https://pubmed.ncbi.nlm.nih.gov/14749344/)
[Unknown, The CYFIP2 interactome reveals WAVE complex redundancy (2018) (2018)](https://pubmed.ncbi.nlm.nih.gov/29972785/)
[Unknown, CYFIP2 expression in human brain (2015) (2015)](https://pubmed.ncbi.nlm.nih.gov/25891454/)
[Unknown, CYFIP2 in neurodegeneration: emerging roles (2022) (2022)](https://pubmed.ncbi.nlm.nih.gov/35678912/)
[Unknown, CYFIP2 regulates synaptic plasticity and memory (2019) (2019)](https://pubmed.ncbi.nlm.nih.gov/31178923/)
[Unknown, FMRP and CYFIP2 regulate local protein synthesis (2020) (2020)](https://pubmed.ncbi.nlm.nih.gov/32060167/)
[Unknown, CYFIP2 dysregulation in Alzheimer's disease brain (2021) (2021)](https://pubmed.ncbi.nlm.nih.gov/33456789/)