The gene adr-1 encodes two isoforms of double stranded RNA adenosine-deaminase (editase) and is well expressed at all stages of development [Hough et al, 1999; Kohara cDNAs], mostly in neurons and in the developing vulva [Tonkin et al, 2002]. It is one of two closely related genes. RNA editing by ADARs is important for normal behavior in Caenorhabditis elegans, as shown by the study of null deletion alleles [Tonkin et al, 2002]. Some ADAR function is required to prevent gene silencing in somatic tissue: transgenes expressed in the somatic tissues of wild-type animals are silenced in strains with deletions in the two genes encoding ADARs, adr-1 and adr-2 [Knight and Bass, 2002]. It lies second in a six gene operon including in that order an essential gene 3I324 (NADH:ubiquinone oxidoreductase complex I, 23.9 kD mitochondrial subunit), gene 3I320 (haloacid dehalogenase-like hydrolase, GS1-like protein), gene 3I318, gene 3I314 (heat shock protein 75) and gene 3I312 (NADH oxidoreductase complex)[Wormbase] adr-2 encodes an adenosine deaminase that acts on RNA (ADAR); ADARs are RNA-editing enzymes that deaminate adenosines to create inosines in double-stranded RNA (dsRNA); adr-2 is expressed ubiquitously in early embryos, as well as in the germline of early adults; ADR-2 is required for ADAR activity in vivo, and for normal chemotaxis.
Wormbase predicts one model, but Caenorhabditis elegans cDNA sequences in GenBank, dbEST, Trace and SRA, filtered against clone rearrangements, coaligned on the genome and clustered in a minimal non-redundant way by the manually supervised AceView program, support at least 2 spliced variants.
AceView synopsis, each blue text links to tables and details Expression: According to AceView, this gene is expressed at high level, 3.0 times the average gene in this release, at all stages of development [Kohara cDNAs], mostly in neurons and in the developing vulva [Tonkin et al, 2002]. The expression profile for the gene, derived from the proportion of animals at each stage in each Kohara library is: embryos 7%, L1 or L2 larvae 67%, L3 to adult 26%. See the in situ hybridization pattern in Kohara NextDB. The sequence of this gene is defined by 19 cDNA clones and 21 elements defined by RNA-seq, some from l2 (seen 7 times), l1 (4), embryo (once), l4 (once). We annotate structural defects or features in 4 cDNA clones. Alternative mRNA variants and regulation: The gene contains 4 distinct gt-ag introns. Transcription produces 2 alternatively spliced mRNAs. Variant a is transpliced to SL1, SL2, SL3, SL4, SL8, SL5, SL9, b to SL3. There are 5 validated alternative polyadenylation sites (see the diagram). The mRNAs appear to differ splicing versus retention of one intron.
Efficacy of translation may be reduced by the presence of a shorter translated product (uORF) initiating at an AUG upstream of the main open reading frame (in variant b). Function: There are 6 articles specifically referring to this gene in PubMed. In addition we point below to 3 abstracts. This gene is associated to a phenotype (abnormal CHEmotaxis, required for normal behaviour). Functionally, the gene has been proposed to participate in a process (RNA processing). Proteins are expected to have molecular functions (adenosine deaminase activity, double-stranded RNA binding activity) and to localize in various compartments (cytoplasm, intracellular). These proteins appear to interact with another protein (ADBP-1). Protein coding potential: The 2 spliced mRNAs putatively encode good proteins, altogether 2 different isoforms (2 complete), some containing domains Adenosine deaminase/editase, double-stranded RNA binding [Pfam].
Please quote: AceView: a comprehensive cDNA-supported gene and transcripts annotation, Genome Biology 2006, 7(Suppl 1):S12. Map on chromosome III, links to other databases and other names Map: This gene adr-2 maps on chomosome III at position -0.74 (interpolated). In AceView, it covers 1.94 kb, from 7232811 to 7230877 (WS190), on the reverse strand. Links to:WormBase, NextDB, RNAiDB. Other names: The gene is also known in Wormgenes/AceView by its positional name 3I322, in Wormbase by its cosmid.number name T20H4.4, in NextDB, the Nematode expression pattern database, as CEYK6994. Closest AceView homologs in other species ? The closest human genes, according to BlastP, are the AceView genes ADARB1 (e=4 10-53), ADAR (e=4 10-53), ADARB2 (e=2 10-47). The closest mouse genes, according to BlastP, are the AceView genes Adarb1 (e=3 10-55), Adar (e=3 10-55). The closest A.thaliana gene, according to BlastP, is the AceView gene AT1G01760 (e=8 10-25)
Alternative mRNAs are shown aligned from 5' to 3' on a virtual genome where introns have been shrunk to a minimal length. Exon size is proportional to length, intron height reflects the number of cDNAs supporting each intron, the small numbers show the support of the introns in deep sequencing (with details in mouse-over) . Introns of the same color are identical, of different colors are different. 'Good proteins' are pink, partial or not-good proteins are yellow, uORFs are green. 5' cap or3' poly A flags show completeness of the transcript. Read more...
Mouse over the ending of each transcript gives tissues from which the supporting cDNAs were extracted. Details on tissue of origin for each intron and exon is available from the intron and exons table.
Click on any transcript to open the specific mRNA page, to see the exact cDNA clone support and eventual SNPs and to get details on tissues, sequences, mRNA and protein annotations. Proteins supported by a single continuous cDNA sequence lead to underlining the name/ending of the variant. Names not underlined result from cDNA concatenation in the coding region and should be experimentally checked.
Introns are depicted by broken lines; the height of the top of each intron reflects the relative number of clones supporting this intron. ]^[ A pink broken line denotes an intron with standard boundaries (gt-ag or gc-ag) that is exactly supported (i.e. a cDNA sequence exactly matches the genome over 16 bp, 8 on both sides of the intron). ] ^ ] A blue broken line denotes non-standard introns, exactly supported, but with non-standard at-ac or any other boundaries. ]-[ Pink and ] - ] blue straight lines represent 'fuzzy' introns of the standard and non-standard types respectively, those introns do not follow the 16 bp rule. Black straight lines ]-[denote gaps in the alignments.
Exons: Wide filled pink areas represent putative protein coding regions, narrow empty pink boxes represent the 5'UTR (on the left) and 3' UTR (on the right). Flags identify validated endings: cap site on the 5' side, polyadenylation site on the 3' side. Filled flags correspond to frequent events while empty flags have lesser supporting cDNAs (yet all are validated); at the 3' side, black flags are associated to the main AATAAA signal, blue flags to any single letter variant of the main . More explanations are given in the gene help file
The mRNAs diagrams with the aligned cDNA sequence accessions and their mismatches are available in the mRNA pages accessible from the tab at the top of the page, or here:
In Flash: .a, .b.
or in GIF: .a, .b
To mine knowledge about the gene, please click the 'Gene Summary' or the 'Function, regulation, related genes ' tab at the top of the page. The 'Gene Summary' page includes all we learnt about the gene, functional annotations of neighboring genes, maps, links to other sites and the bibliography. The 'Function, regulation, related genes ' page includes Diseases (D), Pathways, GO annotations, conserved domains (C), interactions (I) reference into function, and pointers to all genes with the same functional annotation.
To compare alternative variants, their summarized annotations, predicted proteins, introns and exons, or to access any sequence, click the 'Alternative mRNAs features' tab. To see a specific mRNA variant diagram, sequence and annotation, click the variant name in the 'mRNA' tab. To examine expression data from all cDNAs clustered in this gene by AceView, click the 'Expression tissue'.
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