E3 ubiquitin-protein ligase that mediates ubiquitination of PIK3C2B and inhibits its activity; mediates the formation of 'Lys-48'-linked polyubiquitin chains; the function inhibits CD4 T-cell activation. Acts as a regulator of retrograde transport: together with MAGEL2, mediates the formation of 'Lys-63'-linked polyubiquitin chains at 'Lys-220' of WASHC1, leading to promote endosomal F-actin assembly (PubMed:23452853). Has a transcriptional repressor activity by cooperating with EPC1. Induces apoptosis by activating Jun N-terminal kinase and p38 kinase and also increases caspase-3-like activity independently of mitochondrial events. May function in male germ cell development. Has DNA-binding activity and preferentially bound to double-stranded DNA. S-ubiquitinyl-[E2 ubiquitin-conjugating enzyme]-L-cysteine + [acceptor protein]-L-lysine = [E2 ubiquitin-conjugating enzyme]-L-cysteine + N(6)-ubiquitinyl-[acceptor protein]-L-lysine. Homomultimerizes. Interacts with PML, EIF3S6, EPC1, CHD4 and EID1. Interacts with MAGED4, MAGEF1 and MAGEL2. Interacts with herpes simplex virus protein ICP0. (Microbial infection) Interacts with M.tuberculosis PtpA, whick blocks TRIM27-promoted JNK/p38 MAPK pathway activation and cell apoptosis. Nuclear or cytoplasmic depending on the cell type (By similarity). Colocalized with PML and EIF3S6 in nuclear bodies. Recruited to retromer-containing endosomes via interaction with MAGEL2 (PubMed:23452853). Expressed in testis namely within the seminiferous tubules. The coiled-coil region mediates interaction with EPC1 and CHD4. The B box and coiled-coil domains mediate interaction with PML. The B box and the distal coiled-coil domains mediate homomultimerisation. The B30.2 domain mediates interaction with EIF3S6. A chromosomal aberration involving TRIM27/RFP is found in papillary thyroid carcinomas (PTCs). Translocation t(6;10)(p21.3;q11.2) with RET. The translocation generates TRIM27/RET and delta TRIM27/RET oncogenes. Belongs to the TRIM/RBCC family.