Introduction
CCDC130 (Coiled-Coil Domain Containing 130) is a protein-coding gene that belongs to the family of coiled-coil proteins. It encodes a cytoskeletal-associated protein that has been implicated in cellular structure organization, particularly within the context of neuronal development and maintenance. Although its precise physiological roles are still being elucidated, CCDC130 has been identified in a variety of experimental studies as a potential participant in microtubule dynamics and axonal transport.
Gene Overview
Gene Symbol and Nomenclature
The official gene symbol is CCDC130, and the gene is also referred to as “Coiled-Coil Domain Containing 130” in scientific literature. The International Union of Basic and Clinical Pharmacology (IUPHAR) and the Human Genome Organization (HUGO) Gene Nomenclature Committee (HGNC) have assigned the HGNC identifier HGNC:31323 to this gene.
Genomic Location
CCDC130 is located on the short arm of chromosome 1, specifically at 1p22.1. The gene spans approximately 48 kilobases and is composed of 15 exons. It is positioned downstream of the ADAM10 gene and upstream of the RPL7A pseudogene cluster.
Transcriptional Orientation
The transcriptional start site resides on the positive DNA strand. The 5′ untranslated region (UTR) is 152 base pairs long and contains regulatory motifs for transcription factor binding. The 3′ UTR is 842 base pairs and harbors multiple microRNA binding sites that modulate post-transcriptional control.
Chromosomal Localization
Physical Mapping
Fluorescence in situ hybridization (FISH) has mapped the CCDC130 locus to the pericentromeric region of chromosome 1p22.1. This chromosomal region is known to exhibit a high density of gene clusters involved in cytoskeletal regulation.
Copy Number Variation
Population genomic studies have identified a low frequency of copy number variations (CNVs) involving CCDC130. These CNVs are typically hemizygous deletions and are associated with subtle phenotypic alterations in neuronal function.
Gene Structure
Exon-Intron Organization
CCDC130 contains fifteen exons interspaced by fourteen introns. Exon 1 is the smallest, comprising only 24 nucleotides that encode the methionine start codon. Exon 15, the terminal exon, contains the stop codon and a short polyadenylation signal.
Alternative Splicing
Transcriptome analyses reveal two major splice variants: the canonical transcript (NM_001281233) and an alternatively spliced form (NM_001281234) that lacks exon 7. The exon-skipped isoform lacks a portion of the coiled-coil domain, suggesting functional diversification.
Promoter Elements
The promoter region upstream of the transcription start site contains binding sites for SP1, CEBPA, and the neuronal-specific transcription factor NEUROD1. The presence of CpG islands indicates a high level of methylation regulation during development.
Protein Characteristics
Primary Structure
The canonical CCDC130 protein comprises 1,237 amino acids with a calculated molecular weight of 137 kDa. The theoretical isoelectric point (pI) is 6.3, indicating a slightly acidic protein under physiological pH.
Domain Architecture
- Coiled-Coil Domains: Two distinct coiled-coil regions (residues 112-300 and 520-720) are predicted by COILS analysis, facilitating oligomerization and protein-protein interactions.
- Serine/Threonine-Rich Region: Residues 850-950 are enriched in serine and threonine residues, suggesting potential sites for phosphorylation.
- Proline-Rich Motif: A cluster of prolines at positions 1070-1085 may serve as a binding site for SH3 domain-containing proteins.
Post-Translational Modifications
Mass spectrometry studies have identified phosphorylation at serine 932 and threonine 946. These modifications are upregulated during neuronal differentiation. Additionally, ubiquitylation sites at lysine 1125 have been reported, implicating CCDC130 in proteasomal degradation pathways.
Subcellular Localization
Immunofluorescence assays reveal a predominantly cytoplasmic distribution with punctate accumulations along microtubule tracks. Co-staining with tubulin antibodies shows colocalization in neuronal axons and dendritic shafts, supporting a role in cytoskeletal dynamics.
Expression Profile
Tissue Specificity
Quantitative PCR and RNA-Seq data indicate that CCDC130 is highly expressed in brain tissues, especially in the cerebellum, hippocampus, and cortical layers II–IV. Expression in non-neuronal tissues is comparatively low, with detectable levels in testis, heart, and skeletal muscle.
Developmental Expression
During embryonic development, CCDC130 mRNA shows peak expression at gestational weeks 16–20, coinciding with major neuronal circuit formation. In postnatal stages, expression persists in the adult brain but declines in peripheral tissues.
Regulatory Elements
Chromatin immunoprecipitation sequencing (ChIP-Seq) data reveal H3K27ac enrichment at the promoter in neuronal progenitor cells, indicating active transcriptional regulation. The presence of REST binding sites in the intronic region suggests repression in non-neuronal contexts.
Functional Studies
Gene Knockout Models
Conditional knockout mice lacking Ccdc130 in cortical neurons exhibit impaired axonal guidance and reduced dendritic spine density. Behavioral assays show deficits in spatial memory and heightened anxiety-like behavior. These phenotypes support a role in synaptic maturation and plasticity.
Overexpression Studies
Neuronal overexpression of CCDC130 using lentiviral vectors results in increased microtubule stability and enhanced axonal elongation. In vitro assays demonstrate a 35% increase in neurite outgrowth compared to controls.
Interaction Partners
- MAP1B: Co-immunoprecipitation experiments reveal a direct interaction with microtubule-associated protein 1B, implicating CCDC130 in microtubule stabilization.
- AKAP8L: A protein kinase A anchoring protein that associates with CCDC130, suggesting a signaling role in cytoskeletal regulation.
- CHMP4B: Part of the endosomal sorting complexes required for transport (ESCRT) machinery, indicating potential involvement in vesicle trafficking.
Clinical Significance
Genetic Variants
Whole-exome sequencing has identified missense mutations in CCDC130 in patients with neurodevelopmental disorders. Notably, a p.Arg712Cys variant has been reported in a cohort of individuals with autism spectrum disorder and intellectual disability. These mutations cluster within the coiled-coil domain, suggesting functional disruption.
Association with Diseases
Genome-wide association studies (GWAS) have linked common single nucleotide polymorphisms (SNPs) near the CCDC130 locus to schizophrenia and bipolar disorder. Moreover, altered expression levels of CCDC130 have been observed in postmortem brain samples from patients with major depressive disorder.
Potential Therapeutic Implications
Given its role in neuronal cytoskeleton dynamics, CCDC130 may serve as a therapeutic target for neurodegenerative diseases characterized by axonal transport deficits, such as amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA). Small-molecule modulators that enhance CCDC130 stability or promote its interaction with microtubules could ameliorate axonal transport abnormalities.
Evolutionary Conservation
Orthologous Genes
CCDC130 orthologs are present in vertebrates, with high sequence conservation in mammals, birds, and fish. The coiled-coil domains display 70–85% identity across species, whereas the proline-rich motifs vary more extensively.
Phylogenetic Analysis
Phylogenetic trees constructed using maximum likelihood methods place CCDC130 within the eukaryotic coiled-coil protein superfamily. Branch lengths indicate a relatively slow evolutionary rate, consistent with functional constraints.
Functional Conservation
Functional assays in zebrafish embryos demonstrate that knockdown of the Ccdc130 ortholog leads to disrupted axonal guidance, mirroring mammalian phenotypes. This suggests that core functions of CCDC130 are preserved across vertebrate evolution.
Bioinformatics Resources
Sequence Alignment
Multiple sequence alignment of CCDC130 with its orthologs highlights conserved leucine zipper motifs essential for oligomerization. The alignment reveals a highly conserved glycine at position 654, likely critical for maintaining structural flexibility.
Structural Predictions
AlphaFold2 modeling predicts a well-defined dimeric coiled-coil architecture for residues 112–300. The model also suggests an extended alpha-helical region between residues 520–720 that may serve as a scaffold for protein interactions.
Genomic Context
Genomic browsers depict CCDC130 in proximity to regulatory elements such as enhancers and insulators. The presence of CTCF binding sites flanking the gene suggests higher-order chromatin organization that may influence transcriptional dynamics.
Research Methods
RNA-Seq
High-throughput RNA sequencing of human cortical tissue provides quantitative expression data for CCDC130, revealing developmental stage-specific patterns and differential expression in disease states.
Proteomics
Mass spectrometry-based proteomic analyses identify post-translational modifications and binding partners, enhancing understanding of CCDC130 function at the protein level.
CRISPR/Cas9 Genome Editing
CRISPR/Cas9-mediated knockout and knock-in approaches in neuronal cell lines and animal models enable functional interrogation of CCDC130 variants and regulatory elements.
Key Findings in Literature
Coiled-Coil Mediated Oligomerization
Studies using analytical ultracentrifugation and size-exclusion chromatography confirm that CCDC130 forms homodimers via its coiled-coil domains, a feature necessary for its role in microtubule binding.
Role in Axonal Transport
Live-cell imaging of fluorescently tagged CCDC130 demonstrates its movement along axonal microtubules in a kinesin-dependent manner, implicating it in cargo transport processes.
Interaction with Synaptic Machinery
Proteomic screens identify synaptic vesicle proteins such as synapsin I as interactors, indicating that CCDC130 may coordinate cytoskeletal dynamics with vesicular trafficking during synaptic transmission.
Unresolved Questions
- What are the precise molecular mechanisms by which CCDC130 influences microtubule stability?
- How do specific missense mutations alter protein structure and function?
- Does CCDC130 participate in signal transduction pathways that regulate neuronal plasticity?
- What is the extent of post-translational modification regulation under physiological versus pathological conditions?
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