Alternative titles; symbols
HGNC Approved Gene Symbol: TRIM22
Cytogenetic location: 11p15.4 Genomic coordinates (GRCh38) : 11:5,689,790-5,710,863 (from NCBI)
TRIM proteins are composed of 3 zinc-binding domains, a RING, a B-box type 1, and a B-box type 2, followed by a coiled-coil region. They are involved in development and cell growth.
By differential screening of cDNA libraries from IFNA (147660)/IFNB (147640) (type I IFN)-treated and untreated Daudi lymphoblastoid cells, Tissot and Mechti (1995) isolated a cDNA encoding TRIM22, which they termed STAF50. Sequence analysis predicted that the 442-amino acid protein is 44% and 41% identical to mouse Rpt1 and human SSA/RO52 (SSA1; 109092), respectively. It contains a ring finger, an intermediate motif, and a CHC3H2 zinc finger in its N terminus, as well as a central bipartite nuclear localization signal. Northern blot analysis revealed expression of a 2.8-kb transcript in type I and, to a lesser extent, type II IFN (IFNG; 147570)-treated cells with the appropriate receptors. In the absence of IFN treatment, TRIM22 was strongly expressed in peripheral blood leukocytes, spleen, thymus, and ovary; it was expressed at basal levels in other tissues. SDS-PAGE analysis showed that TRIM22 is expressed as a 54-kD protein. Functional analysis indicated that TRIM22 downregulates transcription directed by the long terminal repeat of HIV-1 in transfected cells, suggesting that TRIM22 may be involved in the transduction of IFN antiviral action.
By EST database searching for B-box-containing proteins, Reymond et al. (2001) identified 37 TRIM members, including TRIM22. Northern blot analysis revealed ubiquitous expression of 4.5- and 3.5-kb transcripts. Fluorescence microscopy demonstrated expression in diffuse cytoplasmic speckles. Confocal microscopy failed to identify a subcellular localization. Interaction mating analysis indicated that TRIM22 does not form a homodimer.
Using FISH, Tissot et al. (1996) mapped the TRIM22 gene to chromosome 11p15, near the SSA1 gene. Reymond et al. (2001) mapped it to the same location by radiation hybrid analysis.
Kelly et al. (2014) reported that the SNP rs1063303, which results in an arg242-to-thr (R242T) substitution in TRIM22, is located at a positively selected site. They found that the frequency of rs1063303 varies up to 10-fold among African, Asian, American, and European ethnicities, with the lowest frequency in Asians. Functional analysis showed that rs1063303 resulted in increased TRIM22 expression and decreased antiviral activity.
Kelly, J. N., Woods, M. W., Xhiku, S., Barr, S. D. Ancient and recent adaptive evolution in the antiviral TRIM22 gene: identification of a single-nucleotide polymorphism that impacts TRIM22 function. Hum. Mutat. 35: 1072-1081, 2014. [PubMed: 24863734] [Full Text: https://doi.org/10.1002/humu.22595]
Reymond, A., Meroni, G., Fantozzi, A., Merla, G., Cairo, S., Luzi, L., Riganelli, D., Zanaria, E., Messali, S., Cainarca, S., Guffanti, A., Minucci, S., Pelicci, P. G., Ballabio, A. The tripartite motif family identifies cell compartments. EMBO J. 20: 2140-2151, 2001. [PubMed: 11331580] [Full Text: https://doi.org/10.1093/emboj/20.9.2140]
Tissot, C., Mechti, N. Molecular cloning of a new interferon-induced factor that represses human immunodeficiency virus type 1 long terminal repeat expression. J. Biol. Chem. 270: 14891-14898, 1995. [PubMed: 7797467] [Full Text: https://doi.org/10.1074/jbc.270.25.14891]
Tissot, C., Taviaux, S. A., Diriong, S., Mechti, N. Localization of Staf50, a member of the ring finger family, to 11p15 by fluorescence in situ hybridization. Genomics 34: 151-153, 1996. [PubMed: 8661041] [Full Text: https://doi.org/10.1006/geno.1996.0258]