DDX1
Description
The DDX1 (DEAD-box helicase 1) is a protein-coding gene located on chromosome 2.
ATP-dependent RNA helicase DDX1 is an enzyme that in humans is encoded by the DDX1 gene. DEAD box proteins, characterized by the conserved motif Asp-Glu-Ala-Asp (DEAD), are putative 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 ribosome and spliceosome assembly. Based on their distribution patterns, some members of this family are believed to be involved in embryogenesis, spermatogenesis, and cellular growth and division. This gene encodes a DEAD box protein of unknown function. It shows high transcription levels in 2 retinoblastoma cell lines and in tissues of neuroectodermal origin. DDX1 has been shown to interact with HNRPK. DDX1 has also been tentatively shown to interact with hCLE/C14orf166/RTRAF and HSPC117 in a cap-binding complex that activates mRNA translation.
DDX1 is an ATP-dependent RNA helicase that unwinds both RNA-RNA and RNA-DNA duplexes. It possesses 5' single-stranded RNA overhang nuclease activity and ATPase activity on various RNA but not DNA polynucleotides. DDX1 may play a role in RNA clearance at DNA double-strand breaks (DSBs), facilitating template-guided repair of transcriptionally active regions of the genome. Along with RELA, it acts as a coactivator to enhance NF-kappa-B-mediated transcriptional activation. DDX1 is a positive transcriptional regulator of cyclin CCND2 expression, binding to the cyclin CCND2 promoter region. It associates with chromatin at the NF-kappa-B promoter region through its interaction with RELA and binds to poly(A) RNA. DDX1 might be involved in 3'-end cleavage and polyadenylation of pre-mRNAs. It is a component of the tRNA-splicing ligase complex, working alongside archease (ZBTB8OS) to facilitate the enzymatic turnover of catalytic subunit RTCB by promoting guanylylation of RTCB, a crucial step in tRNA ligation. DDX1 is part of a multi-helicase-TICAM1 complex that functions as a cytoplasmic sensor of viral double-stranded RNA (dsRNA), activating a cascade of antiviral responses, including the induction of pro-inflammatory cytokines through the adapter molecule TICAM1. DDX1 binds specifically (via its helicase ATP-binding domain) to both short and long poly(I:C) dsRNA.
DDX1 is also known as DBP-RB, UKVH5d.
