Essential protein that binds to polyadenylated RNA and single-stranded DNA (PubMed:8474438). It may be involved not only in RNA processing but also in transcription regulation. Associates directly with nascent RNA polymerase II transcripts and remain associated during subsequent nuclear RNA processing reactions (Probable). Involved in mRNA poly(A) tail length control and nuclear export (PubMed:11927564, PubMed:11779864). Functions in surveillance and the packaging leading to generation of export-competent mRNPs. Controls both mRNP compaction that facilitates movement through nuclear pore complexes and the length of transcript poly(A) tails (PubMed:19840948, PubMed:22560733). Interacts with MLP1. Localizes to the nucleus at steady-state, it shuttles between nucleus and cytoplasm. The N-terminal domain is required for nuclear export of both poly(A) RNA and NAB2. The RGG domain is important for NAB2 import. Contains seven CCCH Zn fingers that bind to A-rich RNAs and fingers 5 to 7 are critical for these function (PubMed:12496292, PubMed:22560733, PubMed:28180315). Binding A(11)G RNA induces dimerization of Zn fingers 5-7 mediated by the spatial arrangement of the fingers promoting each RNA chain binding two protein chains (PubMed:28180315). Methylated by HMT1. Present with 9670 molecules/cell in log phase SD medium. Belongs to the NAB2 family.