CRKL Gene

CRKL Gene

Overview

CRKL Gene

Overview

<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">CRKL Gene</th>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>CRKL</td>
</tr>
<tr>
<td class="label">Gene Name</td>
<td>CRK-like proto-oncogene adaptor protein</td>
</tr>
<tr>
<td class="label">Chromosomal Location</td>
<td>22q11.21</td>
</tr>
<tr>
<td class="label">Entrez Gene ID</td>
<td>1399</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>P46109</td>
</tr>
<tr>
<td class="label">Protein Length</td>
<td>303 amino acids</td>
</tr>
<tr>
<td class="label">Molecular Weight</td>
<td>~34 kDa</td>
</tr>
<tr>
<td class="label">Domain</td>
<td>Position</td>
</tr>
<tr>
<td class="label">SH2 domain</td>
<td>6-106 aa</td>
</tr>
<tr>
<td class="label">N-terminal SH3</td>
<td>126-180 aa</td>
</tr>
<tr>
<td class="label">C-terminal SH3</td>
<td>237-293 aa</td>
</tr>
<tr>
<td class="label">Binding partners</td>
<td>Over 50 known interactors</td>
</tr>
<tr>
<td class="label">Post-translational modification</td>
<td>Tyrosine phosphorylation, SUMOylation</td>
</tr>
<tr>
<td class="label">Subcellular localization</td>
<td>Cytoplasm, plasma membrane</td>
</tr>
<tr>
<td class="label">Half-life</td>
<td>~8 hours in cultured cells</td>
</tr>
<tr>
<td class="label">Cancer Type</td>
<td>CRKL Role</td>
</tr>
<tr>
<td class="label">Chronic myeloid leukemia</td>
<td>BCR-ABL substrate</td>
</tr>
<tr>
<td class="label">Gastric cancer</td>
<td>Oncogenic driver</td>
</tr>
<tr>
<td class="label">Pancreatic cancer</td>
<td>Metastasis promoter</td>
</tr>
<tr>
<td class="label">Breast cancer</td>
<td>Growth promoter</td>
</tr>
<tr>
<td class="label">Melanoma</td>
<td>Invasion mediator</td>
</tr>
<tr>
<td class="label">Liver cancer</td>
<td>Tumor progression</td>
</tr>
<tr>
<td class="label">Mechanism</td>
<td>Evidence</td>
</tr>
<tr>
<td class="label">Growth factor signaling</td>
<td>CRKL mediates neurotrophin signaling</td>
</tr>
<tr>
<td class="label">Cellular stress response</td>
<td>CRKL activates stress-responsive kinases</td>
</tr>
<tr>
<td class="label">Synaptic plasticity</td>
<td>CRKL in postsynaptic density signaling</td>
</tr>
<tr>
<td class="label">Partner</td>
<td>Interaction Type</td>
</tr>
<tr>
<td class="label">BCR-ABL</td>
<td>Phosphorylation substrate</td>
</tr>
<tr>
<td class="label">GRB2</td>
<td>SH3 binding</td>
</tr>
<tr>
<td class="label">SOS1</td>
<td>SH3 binding</td>
</tr>
<tr>
<td class="label">C3G</td>
<td>SH3 binding</td>
</tr>
<tr>
<td class="label">ABL1</td>
<td>SH3 binding</td>
</tr>
<tr>
<td class="label">CRK</td>
<td>Homology</td>
</tr>
<tr>
<td class="label">GAB1</td>
<td>SH2 binding</td>
</tr>
<tr>
<td class="label">EGFR</td>
<td>Phosphorylation</td>
</tr>
<tr>
<td class="label">PDGFRA</td>
<td>Phosphorylation</td>
</tr>
<tr>
<td class="label">LRRK2</td>
<td>Potential interaction</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/ms" style="color:#ef9a9a">Ms</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">13 edges</a></td>
</tr>
</table>

CRKL (CRK-like proto-oncogene) is a gene encoding an adaptor protein that plays critical roles in intracellular signal transduction. The protein contains SH2 and SH3 domains that mediate protein-protein interactions, linking various upstream receptors to downstream signaling pathways including RAS, JNK, and ERK. CRKL is essential for normal development and has been extensively studied for its role in cancer and leukemia. [@gu2002]

Gene Structure and Expression

Genomic Organization

The CRKL gene is located on chromosome 22q11.21, within a region commonly deleted in DiGeorge syndrome (22q11.2 deletion syndrome). The gene spans approximately 12 kb and consists of 12 exons that encode the 303-amino acid adaptor protein.

Tissue Distribution

CRKL is expressed ubiquitously in human tissues, with highest expression in:

• Brain: Particularly in neurons of the cerebral cortex and hippocampus
• Hematopoietic cells: High expression in lymphoid and myeloid lineages
• Embryonic tissues: Essential for embryonic development
• Epithelial tissues: Moderate expression in various epithelia

Transcriptional Regulation

CRKL expression is regulated by multiple mechanisms:

• Growth factors: EGF, PDGF induce CRKL expression
• Oncogenic signals: BCR-ABL increases CRKL phosphorylation and activity
• Cellular stress: UV radiation and oxidative stress modulate expression
• Transcriptional factors: SP1 and AP-1 regulate CRKL promoter

Protein Structure and Function

Structural Features

CRKL contains three conserved protein domains:

Modular Architecture

• SH2 domain (src homology 2): Mediates binding to phosphorylated tyrosine residues on target proteins, particularly those in receptor tyrosine kinase signaling cascades
• N-terminal SH3 domain: Binds to proline-rich motifs, facilitating recruitment of downstream effectors
• C-terminal SH3 domain: Provides additional protein interaction surfaces, enabling multi-protein complex formation

Key Biochemical Properties

Core Functions

Role in Signal Transduction Pathways

RAS-RAF-MEK-ERK Pathway

CRKL is a key intermediate in receptor tyrosine kinase (RTK) signaling to the RAS pathway:

RTK activation → GRB2/SOS recruitment → RAS activation → RAF → MEK → ERK
↑
CRKL (adaptor)

CRKL bridges receptor activation to RAS guanine nucleotide exchange, amplifying MAPK signaling.

JNK/c-Jun Pathway

CRKL contributes to JNK pathway activation through multiple mechanisms:

• Direct recruitment: CRKL links RTK signals to JNK kinase cascades
• MKK4/7 activation: Mediates upstream kinase activation
• c-Jun phosphorylation: Contributes to transcription factor activation

BCR-ABL Signaling

In chronic myeloid leukemia (CML), CRKL is a critical substrate of BCR-ABL:

• Phosphorylation by BCR-ABL: CRKL is heavily phosphorylated in BCR-ABL-positive cells
• Oncogenic signaling: CRKL contributes to transformed phenotype
• Therapeutic target: BCR-ABL inhibitors reduce CRKL phosphorylation

Clinical Significance

Cancer

Mechanisms in Cancer

• Cell proliferation: Enhanced RAS-ERK signaling drives cell growth
• Survival: Akt pathway activation promotes cell survival
• Invasion: Matrix metalloproteinase upregulation
• Angiogenesis: VEGF pathway crosstalk
• Chemotherapy resistance: Enhanced DNA repair

Hematological Disorders

• Chronic myeloid leukemia: CRKL phosphorylation serves as BCR-ABL activity marker
• Acute lymphoblastic leukemia: CRKL involvement in ALL pathogenesis
• Myeloproliferative disorders: Altered CRKL signaling

Relationship to Neurodegeneration

Parkinson's Disease

Recent research has identified connections between CRKL and Parkinson's disease:

• Dopaminergic neuron signaling: CRKL participates in signaling pathways important for dopaminergic neuron survival
• LRRK2 interaction: CRKL may intersect with LRRK2 (leucine-rich repeat kinase 2) signaling, a major PD gene
• Protein aggregation: Altered signaling may contribute to protein aggregation pathways

Alzheimer's Disease

• Tau phosphorylation: CRKL may influence kinases involved in tau pathology
• APP processing: Potential role in amyloid precursor protein processing
• Synaptic signaling: CRKL is enriched in synapses and may modulate synaptic function

Neurodevelopmental Disorders

• 22q11.2 deletion syndrome: CRKL haploinsufficiency contributes to neurodevelopmental phenotypes
• Schizophrenia: Association with altered brain development
• Cognitive function: Role in hippocampal signaling

Neuroprotection Mechanisms

Interactions and Pathway Membership

Protein Interactions

Pathway Involvement

CRKL participates in multiple signaling pathways:

• MAPK/ERK pathway: Receptor tyrosine kinase to RAS to ERK
• JNK pathway: Stress-activated protein kinase cascade
• PI3K-AKT pathway: Through GAB1 and other adaptors
• RAP1 pathway: Through C3G and other effectors
• Integrin signaling: Cell adhesion and migration

Therapeutic Implications

Cancer Therapy

• BCR-ABL inhibitors: Imatinib and related drugs reduce CRKL phosphorylation
• Targeted therapy: CRKL itself as potential therapeutic target
• Combination therapy: CRKL inhibition with conventional chemotherapy

Neurological Disorders

• LRRK2 inhibitors: May affect CRKL-associated pathways
• Neuroprotective strategies: Modulating CRKL-dependent survival pathways
• Drug development: Small molecules targeting CRKL protein interactions

Animal Models

Knockout Mice

Crkl knockout mice exhibit:

• Embryonic lethality: Most die during embryonic development
• Cardiac defects: Abnormal heart development
• Neural crest defects: Craniofacial abnormalities
• Hematopoietic abnormalities: Altered blood cell development

Transgenic Models

• CRKL overexpression: Enhanced tumor formation in mouse models
• BCR-ABL/CRKL models: Synergistic leukemogenic effects

Genetic Variation

Polymorphisms and Mutations

• Somatic mutations: Found in various cancers
• Germline variants: Potential role in disease susceptibility
• Copy number alterations: Amplification in some cancers

See Also

• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Parkinson's Disease](/diseases/parkinsons-disease)

External Links

• [PubMed](https://pubmed.ncbi.nlm.nih.gov/)
• [KEGG Pathways](https://www.genome.jp/kegg/pathway.html)

References

Pathway Diagram

The following diagram shows the key molecular relationships involving CRKL Gene discovered through SciDEX knowledge graph analysis: