Paraspeckle component 1

PSPC1 (paraspeckle component 1) is an RNA-binding protein essential for nuclear paraspeckle assembly and function (UniProt: Q8WXF1). It binds poly(A), poly(G), and poly(U) RNA homopolymers and cooperatively regulates androgen receptor-mediated transcription with NONO and SFPQ. The protein also participates in circadian clock regulation by repressing CLOCK-BMAL1 activity and functions in innate immune responses through assembly into the HDP-RNP complex, facilitating IRF3 phosphorylation via the cGAS-STING pathway.

PSPC1 is primarily localized to nuclear compartments where paraspeckles form, participating in post-transcriptional gene regulation. UniProt records no primary disease associations for this protein. Alzheimer's Disease relevance derives from proteomics profiling rather than clinical annotation.

In human post-mortem AD brain tissue, PSPC1 shows ambiguous regulation across subcellular fractions (mean log2 fold-change: −0.11) measured by TMT-labeled mass spectrometry across four fractions (Chaparral AD proteomics). The minimal and inconsistent change suggests PSPC1 abundance is largely preserved in AD pathology, though subcellular redistribution cannot be excluded without examining individual fraction directionality.