PRPF6 - Pre-mRNA Processing Factor 6

PRPF6 — Pre-mRNA Processing Factor 6

<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">PRPF6 - Pre-mRNA Processing Factor 6</th>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>PRPF6</td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>Pre-mRNA Processing Factor 6</td>
</tr>
<tr>
<td class="label">Chromosomal Location</td>
<td>20q13.33</td>
</tr>
<tr>
<td class="label">NCBI Gene ID</td>
<td>24148</td>
</tr>
<tr>
<td class="label">OMIM</td>
<td>613435</td>
</tr>
<tr>
<td class="label">Ensembl ID</td>
<td>ENSG00000163798</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>O94906</td>
</tr>
<tr>
<td class="label">Aliases</td>
<td>U5-102K, C20orf14</td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">1 edges</a></td>
</tr>
</table>

Introduction

PRPF6 — Pre-mRNA Processing Factor 6

<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">PRPF6 - Pre-mRNA Processing Factor 6</th>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>PRPF6</td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>Pre-mRNA Processing Factor 6</td>
</tr>
<tr>
<td class="label">Chromosomal Location</td>
<td>20q13.33</td>
</tr>
<tr>
<td class="label">NCBI Gene ID</td>
<td>24148</td>
</tr>
<tr>
<td class="label">OMIM</td>
<td>613435</td>
</tr>
<tr>
<td class="label">Ensembl ID</td>
<td>ENSG00000163798</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>O94906</td>
</tr>
<tr>
<td class="label">Aliases</td>
<td>U5-102K, C20orf14</td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">1 edges</a></td>
</tr>
</table>

Introduction

PRPF6 (Pre-mRNA Processing Factor 6) is a key component of the spliceosomal U4/U6.U5 tri-snRNP (small nuclear ribonucleoprotein) complex, which is essential for pre-mRNA splicing in eukaryotic cells. As a spliceosomal protein, PRPF6 plays a critical role in the assembly and stabilization of the spliceosome, the molecular machine that removes introns from precursor messenger RNAs[@will2001]. PRPF6 is ubiquitously expressed and particularly important in tissues with high splicing demands, including the brain and retina. Mutations in PRPF6 have been linked to retinitis pigmentosa, a degenerative eye disease, suggesting its critical role in photoreceptor function[@graham2007]. Additionally, emerging research indicates that spliceosomal dysfunction may contribute to neurodegenerative diseases including Alzheimer's disease and Parkinson's disease[@lerner2014].

Gene and Protein Structure

Gene Information

Protein Structure

PRPF6 is a large protein (~930 amino acids, ~102 kDa) with multiple functional domains:

PRPF6 functions as a molecular scaffold that stabilizes the interactions between U4 and U6 snRNAs within the tri-snRNP complex. The protein makes extensive contacts with both U4 and U6 snRNAs, helping to maintain the proper conformation of the snRNA complex essential for splicing catalysis[@valadkhan2010].

Biological Function

Spliceosome Assembly

The spliceosome catalyzes pre-mRNA splicing through a complex assembly pathway involving five small nuclear RNAs (U1, U2, U4, U5, and U6) and numerous associated proteins. PRPF6 participates in several critical steps:

Tri-snRNP recruitment: PRPF6 is a core component of the U4/U6.U5 tri-snRNP, one of the most abundant spliceosomal complexes. The tri-snRNP is recruited to the spliceosome after U1 and U2 snRNPs recognize the 5' splice site and branch point, respectively[@konig2010].

Spliceosome activation: The tri-snRNP undergoes significant structural rearrangements during spliceosome activation, where PRPF6 helps stabilize the activated complex. This involves the release of U4 snRNA and formation of the catalytically active spliceosome[@wahl2009].

Splicing catalysis: During the two transesterification reactions that remove the intron, PRPF6 contributes to maintaining the proper positioning of the splice site elements and the catalytic center of the spliceosome.

Spliceosome disassembly: After splicing is complete, PRPF6 participates in the disassembly of the post-catalytic spliceosome, facilitating recycling of the snRNP components.

Role in Neural Function

Splicing is particularly important in neuronal cells due to the complex patterns of gene expression required for neural development, synaptic plasticity, and function. PRPF6 is essential for:

Alternative splicing regulation: The brain exhibits the highest level of alternative splicing in the body. PRPF6-containing spliceosomes process thousands of neuronal pre-mRNAs, generating protein isoforms with distinct functions.

Synaptic protein expression: Many synaptic proteins, including neurotransmitter receptors, ion channels, and scaffold proteins, require precise splicing for proper function. PRPF6-mediated splicing generates diverse receptor isoforms that modulate synaptic transmission.

Neural development: During development, stage-specific splicing patterns regulate neurogenesis, migration, and differentiation. Disruption of splicing machinery components can lead to neurodevelopmental disorders.

Disease Associations

Retinitis Pigmentosa

PRPF6 mutations cause autosomal dominant retinitis pigmentosa (ADRP), a progressive degenerative disease of the retina characterized by:

• Night blindness
• Peripheral vision loss
• Tunnel vision
• Eventually complete blindness

• Impaired splicing of photoreceptor-specific transcripts
• Cellular stress from accumulated unspliced pre-mRNAs
• Apoptotic cell death[@tanackovic2011]

Neurodegenerative Diseases

While PRPF6 mutations are not directly linked to AD or PD, the spliceosome has emerged as a relevant pathway in neurodegeneration:

Alzheimer's disease: Alternative splicing dysregulation is a feature of AD. Changes in splicing factor expression and splicing patterns have been documented in AD brains. Splicing of tau (MAPT) and APP transcripts may be affected, potentially influencing disease pathogenesis.

Parkinson's disease: Splicing alterations have been observed in PD, including changes in splicing of genes involved in mitochondrial function, protein quality control, and dopamine signaling.

Amyotrophic lateral sclerosis (ALS): Mutations in several splicing-related genes (FUS, TDP-43) cause ALS, demonstrating that splicing dysfunction can be directly pathogenic in motor neurons. While PRPF6 mutations are not known to cause ALS, the general importance of splicing regulation in neurodegeneration is established[@scotti2015].

Spinal muscular atrophy: Survival motor neuron (SMN) protein deficiency affects spliceosome assembly, demonstrating links between splicing and motor neuron disease.

Cardiovascular Disease

Alternative splicing is critical for cardiovascular function, and PRPF6-mediated splicing affects:

• Cardiac ion channel isoforms
• Contractile protein variants
• Signaling pathway components[@danckwardt2017]

Expression Patterns

PRPF6 is expressed in all tissues examined, with highest expression in:

• Brain: Particularly high in cerebral cortex, hippocampus, and cerebellum
• Retina: High expression in photoreceptor cells
• Testis: Elevated expression during spermatogenesis
• Heart: Moderate expression in cardiac muscle

Therapeutic Implications

Splice-Modulating Therapies

The spliceosome represents a therapeutic target:

• Antisense oligonucleotides: Can be designed to modulate specific splicing events
• Small molecule spliceosome modulators: Several drugs targeting the spliceosome are in development for cancer
• Gene therapy: For PRPF6-associated retinitis pigmentosa, gene supplementation approaches are under investigation

Neurodegeneration Research

Understanding the role of splicing in neurodegeneration may lead to:

• Biomarkers based on splicing patterns
• Therapeutic strategies targeting splicing dysregulation
• Combination approaches addressing multiple aspects of disease pathology

Key Publications

See Also

• [Spliceosome](/mechanisms/spliceosome) — Related mechanism
• [RNA Splicing](/mechanisms/rna-splicing) — Related mechanism
• [Retinitis Pigmentosa](/diseases/retinitis-pigmentosa) — Related disease
• [Alzheimer's Disease](/diseases/alzheimers-disease) — Related disease
• [Parkinson's Disease](/diseases/parkinsons-disease) — Related disease
• [Alternative Splicing](/mechanisms/alternative-splicing) — Related mechanism