it has been shown that small nuclear rna ( snrna ) species u1 , u2 , u4 , u5 , and u6 are found in the nucleus in the form of small nuclear ribonucleoprotein particles ( snrnps ) , and that anti-sm antibodies react with snrnp polypeptides , which are associated with all five snrnas .
C0035709
small nuclear rna
C0007610
nucleus