Tripartite motif family

The tripartite motif family (TRIM) is a protein family.^[1]

Function

Many TRIM proteins are induced by interferons, which are important component of resistance to pathogens and several TRIM proteins are known to be required for the restriction of infection by lentiviruses. TRIM proteins are involved in pathogen-recognition and by regulation of transcriptional pathways in host defence.^[2]

Structure

The tripartite motif is always present at the N-terminus of the TRIM proteins. The TRIM motif includes the following three domains:^[1]

• (1) a RING finger domain
• (2) one or two B-box zinc finger domains
  • when only one B-box is present, it is always a type-2 B-box
  • when two B-boxes are present the type-1 B-Box always precedes the type-2 B-Box
• (3) coiled coil region

The C-terminus of TRIM proteins contain either:

• Group 1 proteins: a C-terminal domain selected from the following list:
  • NHL and IGFLMN domains, either in association or alone
  • PHD domain associated with a bromodomain
  • MATH domain (in e.g., TRIM37)
  • ARF domain (in e.g., TRIM23)
  • EXOIII domain (in e.g., TRIM19) or
• Group 2 proteins: a SPRY C-terminal domain
  • e.g. TRIM21

Family members

The TRIM family is split into two groups that differ in domain structure and genomic organization:^[3]

• Group 1 members possess a variety of C-terminal domains, and are represented in both vertebrate and invertebrates
• Group 2 is absent in invertebrates, possess a C-terminal SPRY domain^[4]

Members of the family include:

• Group 1
  • PHD-BROMO domain containing: TRIM24 (TIF1α), TRIM28 (TIF1β), TRIM33 (TIF1γ)– act as corepressors
  • 1-10: TRIM1, TRIM2, TRIM3, TRIM8, TRIM9
  • 11-20: TRIM12, TRIM13, TRIM14, TRIM16, TRIM18, TRIM19
  • 21-30: TRIM23, TRIM25, TRIM29, TRIM30
  • 31-40: TRIM32, TRIM36, TRIM37
  • 41-50: TRIM42, TRIM44, TRIM45, TRIM46, TRIM47
  • 51-60: TRIM51, TRIM53, TRIM54, TRIM55, TRIM56, TRIM57, TRIM59
  • 61-70: TRIM62, TRIM63, TRIM65, TRIM66, TRIM67, TRIM69, TRIM70
  • 71-75: TRIM71
• Group 2
  • 1-10: TRIM4, TRIM5, TRIM6, TRIM7, TRIM10
  • 11-20: TRIM11, TRIM12, TRIM15, TRIM17, TRIM20
  • 21-30: TRIM21, TRIM22, TRIM26, TRIM27, TRIM30
  • 31-40: TRIM31, TRIM34, TRIM35, TRIM38, TRIM39, TRIM40
  • 41-50: TRIM41, TRIM43, TRIM48, TRIM49, TRIM50
  • 51-60: TRIM51, TRIM52, TRIM53, TRIM57, TRIM58, TRIM60
  • 61-70: TRIM61, TRIM64, TRIM68, TRIM69, TRIM70
  • 71-75: TRIM72, TRIM73, TRIM74, TRIM75

References

1. 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 PG, Ballabio A (May 2001). "The tripartite motif family identifies cell compartments". EMBO J. 20 (9): 2140–51. doi:10.1093/emboj/20.9.2140. PMC 125245. PMID 11331580.
2. Ozato K, Shin DM, Chang TH, Morse HC (November 2008). "TRIM family proteins and their emerging roles in innate immunity". Nat. Rev. Immunol. 8 (11): 849–60. doi:10.1038/nri2413. PMC 3433745. PMID 18836477.
3. Sardiello M, Cairo S, Fontanella B, Ballabio A, Meroni G (2008). "Genomic analysis of the TRIM family reveals two groups of genes with distinct evolutionary properties". BMC Evol. Biol. 8: 225. doi:10.1186/1471-2148-8-225. PMC 2533329. PMID 18673550.
4. Ponting C, Schultz J, Bork P (June 1997). "SPRY domains in ryanodine receptors (Ca(2+)-release channels)". Trends Biochem. Sci. 22 (6): 193–4. doi:10.1016/S0968-0004(97)01049-9. PMID 9204703.