PRY/SPRY domain of tripartite motif-binding protein 5, 6, 22 and 34 (TRIM5, TRIM6, TRIM22 and TRIM34)
This domain, consisting of the distinct N-terminal PRY subdomain followed by the SPRY subdomain, is found at the C-terminus of very close paralogs, TRIM5, TRIM6, TRIM22 and TRIM34. These domains are composed of RING/B-box/coiled-coil core and are also known as RBCC proteins. They form a locus of four closely related TRIM genes within an olfactory receptor-rich region on chromosome 11 of the human genome. Genetic analysis of this locus indicates that these four genes have evolved by gene duplication from a common ancestral gene. All genes in the TRIM6/TRIM34/TRIM5/TRIM22 locus are type I interferon inducible, with TRIM5 and TRIM22 possessing antiviral properties. TRIM5 promotes innate immune signaling by activating the TAK1 kinase complex by cooperating with the heterodimeric E2, UBC13/UEV1A. It also stimulates NFkB and AP-1 signaling, and the transcription of inflammatory cytokines and chemokines, amplifying these activities upon retroviral infection. Interaction of its PRY-SPRY or cyclophilin domains with the retroviral capsid lattice stimulates the formation of a complementary lattice by TRIM5, with greatly increased TRIM5 E3 activity, and host cell signal transduction. TRIM6 is selectively expressed in embryonic stem (ES) cells and interacts with the proto-oncogene product Myc, maintaining the pluripotency of the ES cells. TRIM6, together with E2 Ubiquitin conjugase (UbE2K) and K48-linked poly-Ub chains, is critical for the IkappaB kinase epsilon (IKKepsilon) branch of type I interferon (IFN-I) signaling pathway and subsequent establishment of a protective antiviral response. TRIM22 plays an integral role in the host innate immune response to viruses; it has been shown to inhibit the replication of a number of viruses, including HIV-1, hepatitis B, and influenza A. Altered TRIM22 expression has also been associated with multiple sclerosis, cancer, and autoimmune disease. While the PRY-SPRY domain of TRIM5a provides specificity and the capsid recognition motif to retroviral restriction, TRIM34 binds HIV-1 capsid but does not restrict HIV-1 infection.
Jiyao W et al.(2023). "The conserved domain database in 2023.",