Identified in a mRNP granule complex, at least composed of ACTB, ACTN4, DHX9, ERG, HNRNPA1, HNRNPA2B1, HNRNPAB, HNRNPD, HNRNPL, HNRNPR, HNRNPU, HSPA1, HSPA8, IGF2BP1, ILF2, ILF3, NCBP1, NCL, PABPC1, PABPC4, PABPN1, RPLP0, RPS3, RPS3A, RPS4X, RPS8, RPS9, SYNCRIP, TROVE2, YBX1 and untranslated mRNAs. Interacts with APTX and NSUN2. Component of the SWAP complex that consists of NPM1, NCL/nucleolin, PARP1 and SWAP70. Component of a complex which is at least composed of HTATSF1/Tat-SF1, the P-TEFb complex components CDK9 and CCNT1, RNA polymerase II, SUPT5H, and NCL/nucleolin. Interacts (via RRM1 and C-terminal RRM4/Arg/Gly-rich domains) with TERT; the interaction is important for nucleolar localization of TERT. Interacts with ERBB4. Interacts with GZF1; this interaction is important for nucleolar localization of GZF1. Interacts with NVL.