2mxt

Structural highlights

Function

[HNRPQ_HUMAN] Heterogenous nuclear ribonucleoprotein (hnRNP) implicated in mRNA processing mechanisms. Component of the CRD-mediated complex that promotes MYC mRNA stability. Isoform 1, isoform 2 and isoform 3 are associated in vitro with pre-mRNA, splicing intermediates and mature mRNA protein complexes. Isoform 1 binds to apoB mRNA AU-rich sequences. Isoform 1 is part of the APOB mRNA editosome complex and may modulate the postranscriptional C to U RNA-editing of the APOB mRNA through either by binding to A1CF (APOBEC1 complementation factor), to APOBEC1 or to RNA itself. May be involved in translationally coupled mRNA turnover. Implicated with other RNA-binding proteins in the cytoplasmic deadenylation/translational and decay interplay of the FOS mRNA mediated by the major coding-region determinant of instability (mCRD) domain. Interacts in vitro preferentially with poly(A) and poly(U) RNA sequences. Isoform 3 may be involved in cytoplasmic vesicle-based mRNA transport through interaction with synaptotagmins. Component of the GAIT (gamma interferon-activated inhibitor of translation) complex which mediates interferon-gamma-induced transcript-selective translation inhibition in inflammation processes. Upon interferon-gamma activation assembles into the GAIT complex which binds to stem loop-containing GAIT elements in the 3'-UTR of diverse inflammatory mRNAs (such as ceruplasmin) and suppresses their translation; seems not to be essential for GAIT complex function.^{[1] [2] [3] [4] [5] [6]}

References

1. ↑ Mourelatos Z, Abel L, Yong J, Kataoka N, Dreyfuss G. SMN interacts with a novel family of hnRNP and spliceosomal proteins. EMBO J. 2001 Oct 1;20(19):5443-52. PMID:11574476 doi:http://dx.doi.org/10.1093/emboj/20.19.5443
2. ↑ Grosset C, Chen CY, Xu N, Sonenberg N, Jacquemin-Sablon H, Shyu AB. A mechanism for translationally coupled mRNA turnover: interaction between the poly(A) tail and a c-fos RNA coding determinant via a protein complex. Cell. 2000 Sep 29;103(1):29-40. PMID:11051545
3. ↑ Lau PP, Chang BH, Chan L. Two-hybrid cloning identifies an RNA-binding protein, GRY-RBP, as a component of apobec-1 editosome. Biochem Biophys Res Commun. 2001 Apr 13;282(4):977-83. PMID:11352648 doi:http://dx.doi.org/10.1006/bbrc.2001.4679
4. ↑ Blanc V, Navaratnam N, Henderson JO, Anant S, Kennedy S, Jarmuz A, Scott J, Davidson NO. Identification of GRY-RBP as an apolipoprotein B RNA-binding protein that interacts with both apobec-1 and apobec-1 complementation factor to modulate C to U editing. J Biol Chem. 2001 Mar 30;276(13):10272-83. Epub 2000 Dec 27. PMID:11134005 doi:http://dx.doi.org/10.1074/jbc.M006435200
5. ↑ Weidensdorfer D, Stohr N, Baude A, Lederer M, Kohn M, Schierhorn A, Buchmeier S, Wahle E, Huttelmaier S. Control of c-myc mRNA stability by IGF2BP1-associated cytoplasmic RNPs. RNA. 2009 Jan;15(1):104-15. doi: 10.1261/rna.1175909. Epub 2008 Nov 24. PMID:19029303 doi:10.1261/rna.1175909
6. ↑ Arif A, Chatterjee P, Moodt RA, Fox PL. Heterotrimeric GAIT complex drives transcript-selective translation inhibition in murine macrophages. Mol Cell Biol. 2012 Dec;32(24):5046-55. doi: 10.1128/MCB.01168-12. Epub 2012 Oct , 15. PMID:23071094 doi:10.1128/MCB.01168-12