DNA/RNA-binding protein that plays a role in various cellular processes such as transcription regulation, RNA splicing, RNA transport, DNA repair and damage response. Binds to nascent pre-mRNAs and acts as a molecular mediator between RNA polymerase II and U1 small nuclear ribonucleoprotein thereby coupling transcription and splicing. Binds also its own pre-mRNA and autoregulates its expression; this autoregulation mechanism is mediated by non-sense-mediated decay. Plays a role in DNA repair mechanisms by promoting D-loop formation and homologous recombination during DNA double-strand break repair (By similarity). In neuronal cells, plays crucial roles in dendritic spine formation and stability, RNA transport, mRNA stability and synaptic homeostasis (PubMed:16317045, PubMed:25968143). Self-oligomerizes (via N-terminal region). Oligomerization is essential for chromatin binding. Component of nuclear riboprotein complexes. Interacts with ILF3, TDRD3 and SF1. Interacts through its C-terminus with SFRS13A. Interacts with OTUB1 and SARNP. Interacts with LRSAM1. Interacts with SAFB1 in a DNA-dependent manner; this interaction tethers FUS to chromatin. Interacts with MATR3. Interacts with SNRNP70 and POLR2A; these interactions couple RNA transcription and splicing. Interacts (through its RNA-binding domain) with RALY (through its RNA-binding domain); both are components of the same RNPs. Displays a punctate pattern inside the nucleus and is excluded from nucleoli. Phosphorylated in its N-terminal serine residues upon induced DNA damage. ATM and DNA-PK are able to phosphorylate FUS N-terminal region. Belongs to the RRM TET family.