Enables U1 snRNP binding activity. Involved in cellular response to retinoic acid; cellular response to transforming growth factor beta stimulus; and cellular response to tumor necrosis factor. Located in cytoplasm and nucleus. Part of U1 snRNP. Human ortholog(s) of this gene implicated in disease of mental health and systemic lupus erythematosus. Orthologous to human SNRNP70 (small nuclear ribonucleoprotein U1 subunit 70). [provided by Alliance of Genome Resources, Apr 2022]