Biology:RHAU
RHAU (RNA Helicase associated with AU-rich element, also known as DHX36 or G4R1) is a 114-kDa human RNA helicase of the DEAH-box family of helicases encoded by the DHX36 gene.[1]
Structure
Structurally, RHAU is a 1008 amino acid-long modular protein. It consists of a ~440-amino acid helicase core comprising all signature motifs of the DEAH-box family of helicases with N- and C-terminal flanking regions of ~180 and ~380 amino acids, respectively. Like all the DEAH-box proteins, the helicase associated domain is located adjacent to the helicase core region and occupies 75% of the C-terminal region.
Function
RHAU exhibits a unique ATP-dependent guanine-quadruplex (G4) resolvase activity and specificity for its substrate in vitro.[2][3] RHAU binds G4-nucleic acid with sub-nanomolar affinity and unwinds G4 structures much more efficiently than double-stranded nucleic acid. Consistent with these biochemical observations, RHAU was also identified as the major source of tetramolecular RNA-resolving activity in HeLa cell lysates.
Previous work showed that RHAU associates with mRNAs and re-localises to stress granules (SGs) upon translational arrest induced by various environmental stresses.[4][5] A region of the first 105 amino acid was shown to be critical for RNA binding and re-localisation to SGs.[4]
References
- ↑ "The human DDX and DHX gene families of putative RNA helicases". Genomics 81 (6): 618–22. June 2003. doi:10.1016/S0888-7543(03)00049-1. PMID 12782131.
- ↑ "The DEXH protein product of the DHX36 gene is the major source of tetramolecular quadruplex G4-DNA resolving activity in HeLa cell lysates". The Journal of Biological Chemistry 280 (46): 38117–20. November 2005. doi:10.1074/jbc.C500348200. PMID 16150737.
- ↑ "G4 resolvase 1 binds both DNA and RNA tetramolecular quadruplex with high affinity and is the major source of tetramolecular quadruplex G4-DNA and G4-RNA resolving activity in HeLa cell lysates". The Journal of Biological Chemistry 283 (50): 34626–34. December 2008. doi:10.1074/jbc.M806277200. PMID 18842585.
- ↑ 4.0 4.1 "Recruitment of the RNA helicase RHAU to stress granules via a unique RNA-binding domain". The Journal of Biological Chemistry 283 (50): 35186–98. December 2008. doi:10.1074/jbc.M804857200. PMID 18854321.
- ↑ Chalupníková, Kateřina (2008). "Characterizing functional domains of the RNA helicase RHAU involved in subcellular localization and RNA interaction". http://edoc.unibas.ch/866/1/DissB_8509.pdf.[unreliable medical source?]
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