Binds the stem-loop structure of replication-dependent histone pre-mRNAs and contributes to efficient 3' end processing by stabilizing the complex between histone pre-mRNA and U7 small nuclear ribonucleoprotein (snRNP) (PubMed:8957003, PubMed:9858606). Could play an important role in targeting mature histone mRNA from the nucleus to the cytoplasm and to the translation machinery. Stabilizes mature histone mRNA and could be involved in cell-cycle regulation of histone gene expression (By similarity). Interacts with mif4gd. Nuclear (coiled bodies). Widely expressed. Very low levels in stage I oocytes, gradually increasing throughout oogenesis. Further increase is achieved during early embryogenesis. Phosphorylated on Thr-60 during mitosis. Belongs to the SLBP family.