The SFPQ (Splicing Factor Proline and Glutamine rich) protein, initially discovered as a splicing factor, is a multifunctional nuclear protein that participates in various cellular processes. Its main partner in the cell is the NONO (Non-POU domain-containing octamer-binding protein) protein. SFPQ forms with NONO a heterodimer, which is an important component of subnuclear compartments called paraspeckles and located near such nuclear structures as splicing speckles. However, SFPQ can participate in some cellular processes independently, so it is SFPQ, but not NONO, that is apparently necessary for cell viability. There is a lot of data on the involvement of SFPQ in the repair of double-stranded DNA breaks, yet the precise mechanism of its involvement in this important cellular process remains unclear. In this review, we have tried to summarize and systematize the existing data on the role of SFPQ and its complex with NONO in the repair of double-stranded DNA breaks.
Agapkina et al. (Wed,) studied this question.