Loss of ZNF32 augments the regeneration of nervous lateral line system through negative regulation of SOX2 transcription

Human zinc finger protein 32 (ZNF32) is a Cys2-His2 zinc-finger transcription factor that plays an important role in cell fate, yet much of its function remains unknown. Here, we reveal that the zebrafish ZNF32 homologue zfZNF32 is expressed in the nervous system, particularly in the lateral line system. ZfZNF32 knock-out zebrafish (zfZNF-/-) were generated using the CRISPR-associated protein 9 system. We found that the regenerative capacity of the lateral line system was increased in zfZNF-/- upon hair cell damage compared with the wild type. Moreover, SOX2 was essential for the zfZNF32-dependent modulation of lateral line system regeneration. Mechanistic studies showed that ZNF32 suppressed SOX2 transcription by directly binding to a consensus sequence (5'-gcattt-3') in the SOX2 promoter. In addition, ZNF32 localizes to the nucleus, and we have identified that amino acids 1-169 (Aa 1-169) and each of three independent nuclear localization signals (NLSs) in ZNF32 are indispensable for ZNF32 nuclear trafficking. Mutating the NLSs disrupted the inhibitory effect of ZNF32 in SOX2 expression, highlighting the critical role of the NLSs in ZNF32 function. Our findings reveal a pivotal role for ZNF32 function in SOX2 expression and regeneration regulation.