Probable subunit of a splicing factor complex required for 'A' complex assembly formed by the stable binding of U2 snRNP to the branchpoint sequence (BPS) in pre-mRNA (By similarity). Involved in male fertility. Probable component of a the U2 small nuclear ribonucleoproteins complex (U2 snRNP). Excluded from the nucleoli. Ubiquitous. In ovaries and testes, it is expressed in all germ and somatic cells. Highly expressed in spermatogonias and spermatocytes. Highly expressed in the germ cells of larval testes, while it is weakly expressed in fat body cells, in polyploid nuclei of salivary glands, and in larval brain. Expressed throughout embryogenesis from syncytial blastoderm stage. 'Noisette' means 'hazel nut' in French, and is due to the small size of testes in mutants. Belongs to the SF3A3 family.