RNA-binding subunit of the trimeric nuclear exosome targeting (NEXT) complex, a complex that functions as an RNA exosome cofactor that directs a subset of non-coding short-lived RNAs for exosomal degradation. NEXT is involved in surveillance and turnover of aberrant transcripts and non-coding RNAs. Binds preferentially polyuridine sequences and associates with newly synthesized RNAs, including pre-mRNAs and short-lived exosome substrates such as promoter upstream transcripts (PROMPTs), enhancer RNAs (eRNAs), and 3'-extended products from small nuclear RNAs (snRNAs). Component of the nuclear exosome targeting (NEXT) complex composed of MTREX, ZCCHC8, and RBM7 that directs a subset of non-coding short-lived RNAs for exosomal degradation. Excluded from the nucleolus. The RRM domain mediates RNA binding; the RNA must have four nucleotides for efficient binding. Mediates the interaction of NEXT complex with promoter upstream transcripts (PROMPTs) and potentially aberrant forms of other non coding RNAs, such as snRNAs. The RRM domain exhibits specificity for polyuridine sequences. Morpholino knockdown of rbm7 causes several degrees of the severity in the phenotype. Mildly affected fish are unable to swim away normally upon touch stimulation. The body shape is slightly shorter and sporadically brain edema could be observed. The moderately affected fish have a curved body shape, smaller head and eyes. Heart and brain edema are frequently observed. In fish with severe phenotype the body shape is completely altered, the tail is absent, and the head and eyes are smaller.