paraspeckles

Definition

Target type: cellularcomponent

Discrete subnuclear bodies in the interchromatin nucleoplasmic space, often located adjacent to nuclear specks. 10-20 paraspeckles are typically found in human cell nuclei. [GOC:jl, PMID:11790299]

Paraspeckles are nuclear bodies that are enriched in non-coding RNA transcripts. They are characterized by their distinct morphology, appearing as irregularly shaped, speckles of varying sizes. The key cellular component of paraspeckles is a specialized nuclear domain composed of a complex network of proteins and RNA molecules.

These structures are built around long non-coding RNAs (lncRNAs), specifically the NEAT1 (nuclear enriched abundant transcript 1) transcripts, which act as scaffold molecules. The NEAT1 lncRNAs fold into intricate three-dimensional structures that provide a platform for the assembly of various proteins. These proteins include:

* **PSP1 (Paraspeckle protein 1):** A key protein that binds to NEAT1 and plays a critical role in the formation and integrity of paraspeckles. PSP1 acts as a central hub, recruiting other paraspeckle components.
* **PSPC1 (Paraspeckle component 1):** Another important protein that binds to NEAT1 and is involved in the regulation of RNA processing and localization.
* **SFPQ (Splicing factor proline-glutamine rich):** A protein that is known to bind to both DNA and RNA, suggesting a potential role in transcriptional regulation.
* **NONO (Nuclear organizer region protein):** A protein that is involved in RNA processing and transport, and it interacts with various other proteins within the paraspeckle.
* **Other proteins:** The paraspeckle proteome is dynamic and includes a diverse range of proteins involved in RNA processing, transcription, and translation.

The dynamic interplay between these proteins and NEAT1 lncRNA creates a functional microenvironment within the paraspeckle, allowing for the regulation of various cellular processes, including:

* **RNA processing:** Paraspeckles are known to be involved in the post-transcriptional regulation of specific mRNAs, including the retention and nuclear localization of these transcripts.
* **Transcriptional regulation:** The presence of transcriptional factors within paraspeckles suggests a potential role in the regulation of gene expression.
* **Stress response:** Paraspeckles have been implicated in cellular responses to stress, such as DNA damage and viral infection.

Understanding the cellular components of paraspeckles is crucial for deciphering their complex functions in maintaining cellular homeostasis and responding to diverse cellular challenges.'
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Proteins (1)

Compounds (3)