DHX36

Probable ATP-dependent RNA helicase DHX36 also known as DEAH box protein 36 (DHX36) or MLE-like protein 1 (MLEL1) or G4 resolvase (G4R1) or RNA helicase associated with AU-rich elements (RHAU) is an is_associated_with::enzyme that in humans is encoded by the DHX36 is_associated_with::gene.

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 is_associated_with::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
is_associated_with::DEAD box proteins, characterized by the conserved motif Asp-Glu-Ala-Asp (DEAD), are putative is_associated_with::RNA helicases. They are implicated in a number of cellular processes involving alteration of RNA secondary structure such as translation initiation, nuclear and mitochondrial splicing, and is_associated_with::ribosome and is_associated_with::spliceosome assembly. Based on their distribution patterns, some members of this DEAD box protein family are believed to be involved in is_associated_with::embryogenesis, is_associated_with::spermatogenesis, and cellular growth and division.

RHAU exhibits a unique ATP-dependent guanine-quadruplex (G4) resolvase activity and specificity for its substrate in vitro. 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 is_associated_with::stress granules (SGs) upon translational arrest induced by various environmental stresses. A region of the first 105 amino acid was shown to be critical for RNA binding and re-localisation to SGs.