E3 ubiquitin-protein ligase TRIM22; EC=6.3.2.-; tripartite motif-containing protein 22; RING finger protein 94; 50 kDa-stimulated trans-acting factor; Staf-50 (TRIM22, RNF94, STAF50)

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Function

interferon-induced antiviral protein involved in cell innate immunity
the antiviral activity could in part be mediated by TRIM22-dependent ubiquitination of viral proteins
plays a role in restricting the replication of HIV-1, encephalomyocarditis virus (EMCV) & hepatitis B virus (HBV)
acts as a transcriptional repressor of HBV core promoter
may have E3 ubiquitin-protein ligase activity
protein modification; protein ubiquitination
auto-ubiquitinated
interacts with HIV-1 Gag polyprotein; interaction seems to reduce gag production or virus budding
interacts with EMCV protease 3C; interaction leads to viral protease ubiquitination

the C-terminal SPRY domain is required for transcriptional suppressor activity, probably by mediating correct nuclear localization
residues 491-494 are essential for nuclear localization & nuclear bodies formation
the RING domain is essential for antiviral activity & for TRIM22 nuclear bodies (NB) formation but is not necessary for nuclear localization
belongs to the TRIM/RBCC family
contains 1 B box-type Zn+2 finger
contains 1 B30.2/SPRY domain
contains 1 RING-type Zn+2 finger

cytoplasm, nucleus, nuclear speckle Cajal body
localizes predominanltly in the nucleus
found in cytoplasm to some extent
forms distinct nuclear bodies that undergo dynamic changes during cell cycle progression
nuclear bodies start to form in the early G0/G1 phase but become speckle-like in the S-phase & completely dispersed in mitosis
35% of TRIM22 nuclear bodies overlap or are found adjacent to Cajal bodies

strongly expressed in peripheral blood leukocytes, spleen, thymus, & ovary
expressed at basal levels in other tissues
induced by interferons alpha & beta
up-regulated by TP53
dramatically induced by progesterone in MDA-MB-231-derived ABC28 cells & T47D cells