REVIEW: Multifunctional SFPQ Protein: Role in Double-Strand DNA Break Repair

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Yulia Yu. Agapkina^1,2, Mariia O. Silkina¹, Tatiana F. Kikhai^1,a, and Marina B. Gottikh^1,2,b*

¹Faculty of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia

²Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia

^* To whom correspondence should be addressed.

Received: July 11, 2025; Revised: September 16, 2025; Accepted: October 6, 2025

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The SFPQ (Splicing Factor Proline and Glutamine rich) protein, initially identified as a splicing factor, is a multifunctional nuclear protein involved in various cellular processes. Its main cellular partner is NONO (Non-POU domain-containing octamer-binding protein), with which SFPQ forms a heterodimer that is a crucial component of subnuclear structures called paraspeckles and located near nuclear speckles. However, SFPQ can also function independently in certain cellular processes and is essential for cell viability. There is substantial evidence of the involvement of SFPQ in the repair of double-strand DNA breaks (DSBs), but a definitive understanding of the mechanism of its participation in this critical cellular process is still lacking. In this review, we aim to summarize and systematize the existing data on the role of SFPQ and its complex with NONO in the repair of double-strand DNA breaks.

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KEY WORDS: SFPQ, DNA repair, double-strand breaks, homologous recombination, non-homologous end joining

DOI: 10.1134/S0006297925602138

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