| Description |
Multifunctional ATP-dependent nucleic acid helicase that unwinds DNA and RNA in a 3' to 5' direction and that plays important roles in many processes, such as DNA replication, transcriptional activation, post-transcriptional RNA regulation, mRNA translation and RNA-mediated gene silencing (PMID:9111062, PMID:11416126, PMID:12711669, PMID:15355351, PMID:16680162, PMID:17531811, PMID:20669935, PMID:21561811, PMID:24049074, PMID:25062910, PMID:24990949, PMID:28221134). Requires a 3'-single-stranded tail as entry site for acid nuclei unwinding activities as well as the binding and hydrolyzing of any of the four ribo- or deoxyribo-nucleotide triphosphates (NTPs) (PMID:1537828). Unwinds numerous nucleic acid substrates such as double-stranded (ds) DNA and RNA, DNA:RNA hybrids, DNA and RNA forks composed of either partially complementary DNA duplexes or DNA:RNA hybrids, respectively, and also DNA and RNA displacement loops (D- and R-loops), triplex-helical DNA (H-DNA) structure and DNA and RNA-based G-quadruplexes (PMID:20669935, PMID:21561811, PMID:24049074). Binds dsDNA, single-stranded DNA (ssDNA), dsRNA, ssRNA and poly(A)-containing RNA (PMID:9111062, PMID:10198287). Binds also to circular dsDNA or dsRNA of either linear and/or circular forms and stimulates the relaxation of supercoiled DNAs catalyzed by topoisomerase TOP2A (PMID:12711669). Plays a role in DNA replication at origins of replication and cell cycle progression (PMID:24990949). Plays a role as a transcriptional coactivator acting as a bridging factor between polymerase II holoenzyme and transcription factors or cofactors, such as BRCA1, CREBBP, RELA and SMN1 (PMID:11149922, PMID:9323138, PMID:9662397, PMID:11038348, PMID:11416126, PMID:15355351, PMID:28221134). Binds to the CDKN2A promoter (PMID:11038348). Plays several roles in post-transcriptional regulation of gene expression (PMID:28221134, PMID:28355180). In cooperation with NUP98, promotes pre-mRNA alternative splicing activities of a subset of genes (PMID:11402034, PMID:16680162, PMID:28221134, PMID:28355180). As component of a large PER complex, is involved in the negative regulation of 3' transcriptional termination of circadian target genes such as PER1 and NR1D1 and the control of the circadian rhythms . Acts also as a nuclear resolvase that is able to bind and neutralize harmful massive secondary double-stranded RNA structures formed by inverted-repeat Alu retrotransposon elements that are inserted and transcribed as parts of genes during the process of gene transposition (PMID:28355180). Involved in the positive regulation of nuclear export of constitutive transport element (CTE)-containing unspliced mRNA (PMID:9162007, PMID:10924507, PMID:11402034). Component of the coding region determinant (CRD)-mediated complex that promotes cytoplasmic MYC mRNA stability (PMID:19029303). Plays a role in mRNA translation (PMID:28355180). Positively regulates translation of selected mRNAs through its binding to post-transcriptional control element (PCE) in the 5'-untranslated region (UTR) (PMID:16680162). Involved with LARP6 in the translation stimulation of type I collagen mRNAs for CO1A1 and CO1A2 through binding of a specific stem-loop structure in their 5'-UTRs (PMID:22190748). Stimulates LIN28A-dependent mRNA translation probably by facilitating ribonucleoprotein remodeling during the process of translation (PMID:21247876). Plays also a role as a small interfering (siRNA)-loading factor involved in the RNA-induced silencing complex (RISC) loading complex (RLC) assembly, and hence functions in the RISC-mediated gene silencing process (PMID:17531811). Binds preferentially to short double-stranded RNA, such as those produced during rotavirus intestinal infection (PMID:28636595). This interaction may mediate NLRP9 inflammasome activation and trigger inflammatory response, including IL18 release and pyroptosis (PMID:28636595). Finally, mediates the attachment of heterogeneous nuclear ribonucleoproteins (hnRNPs) to actin filaments in the nucleus (PMID:11687588). (Microbial infection) Plays a role in HIV-1 replication and virion infectivity (PMID:11096080, PMID:19229320, PMID:25149208, PMID:27107641). Enhances HIV-1 transcription by facilitating the binding of RNA polymerase II holoenzyme to the proviral DNA (PMID:11096080, PMID:25149208). Binds (via DRBM domain 2) to the HIV-1 TAR RNA and stimulates HIV-1 transcription of transactivation response element (TAR)-containing mRNAs (PMID:9892698, PMID:11096080). Involved also in HIV-1 mRNA splicing and transport (PMID:25149208). Positively regulates HIV-1 gag mRNA translation, through its binding to post-transcriptional control element (PCE) in the 5'-untranslated region (UTR) (PMID:16680162). Binds (via DRBM domains) to a HIV-1 double-stranded RNA region of the primer binding site (PBS)-segment of the 5'-UTR, and hence stimulates DHX9 incorporation into virions and virion infectivity (PMID:27107641). Plays also a role as a cytosolic viral MyD88-dependent DNA and RNA sensors in plasmacytoid dendritic cells (pDCs), and hence induce antiviral innate immune responses (PMID:20696886, PMID:21957149). Binds (via the OB-fold region) to viral single-stranded DNA unmethylated C-phosphate-G (CpG) oligonucleotide (PMID:20696886). |
| Other names |
ATP-dependent RNA helicase A, EC 3.6.4.13, DEAH box protein 9, DExH-box helicase 9, Leukophysin, LKP, Nuclear DNA helicase II, NDH II, RNA helicase A, DHX9, DDX9 LKP NDH2 |
