Disease relevance of Ddx6

• Induction of a novel nuclear protein (p54) by phorbol esters in mouse erythroleukemia (Friend) cells [1].
• Host protein synthesis in Sac(-) cells infected with mouse hepatitis virus strain A59 was inhibited, and the following novel proteins appeared: gp150, gp90, p54, gp26.5, gp25.5, p24, p22, and p14 [2].

High impact information on Ddx6

• The rck/p54 candidate proto-oncogene product is a 54-kilodalton D-E-A-D box protein differentially expressed in human and mouse tissues [3].
• In a variant cell line of Friend cells which exhibits resistance to TPA in erythroid differentiation, p54 was not induced by TPA [1].
• The induction of p54 by TPA was counteracted by erythroid-inducing agents including dimethyl sulfoxide, hexamethylenebisacetamide, and actinomycin D [1].
• PAK1 is in turn bound by Rac1. c-Jun NH2-terminal kinase-p46 is phosphorylated and activated only when laminin is present, and the p54 isoform is activated when laminin is depleted or binding is inhibited with heparin [4].
• In rat-1 fibroblasts, the p46 kDa, but not the p54 kDa, isoforms of JNK expressed circadian rhythms in phosphorylation [5].

Biological context of Ddx6

• All positive mouse genomic recombinant clones, and cDNA clones containing mouse Ddx6 (previous gene symbol: Rck), were localized by fluorescent in situ hybridization to band B of mouse Chromosome 9, a region showing conserved linkage homology to human chromosome 11 band q23 [6].
• In the current study, we investigated the expression of rck/p54 in mouse gametogenesis and early embryogenesis [7].
• rck/p54, a DEAD-box RNA helicase, is closely associated with the basic modification of RNA molecules in the process of mRNA transport, RNA decay, and translation initiation [8].
• The deduced amino acid sequence of an open reading frame from a cDNA clone revealed a protein with 92.5% identity to human ddx6/p54 [6].
• We determined the nucleotide sequence of the fragment containing the rck locus [9].

Anatomical context of Ddx6

• RCK/p54 mRNAs are most abundant in growing oocytes; steady state levels decline in primary and secondary oocytes, and degradation appears to be complete by the mid-late two-cell stage [10].
• Western blot analysis revealed that rck/p54 was highly expressed in both the ovary and testis [7].
• Interestingly, rck/p54 was concentrated in the heads of spermatozoa; and then its expression gradually decreased as these cells matured along the epididymal duct [7].
• After fertilization, rck/p54 protein and its mRNA remained present in the pronucleus phase; and then their expression levels slightly but definitely decreased in morulae and blastocytes [7].
• The injection of a CMV-based rck/p54 expression vector into the pronuclei of fertilized eggs caused a delay in early embryogenesis [7].

Other interactions of Ddx6

• Zygotic transcription of MSY1 and RCK/p54 is evident in four-cell stage embryos [10].

Analytical, diagnostic and therapeutic context of Ddx6

• A 7.5-kb mRNA and a 54-kDa protein were identified as mouse Ddx6 gene products which are similar in size to products of the human DDX6 gene, as shown by Northern and Western blot analyses [6].
• In addition, the rck/p54 protein was localized to cytoplasm by immunostaining with the use of laser microscopy and by subcellular fractionation [3].

References