Caenorhabditis elegans gene clk-1, CLocK (biological timing) abnormality, encoding COenzyme Q (ubiquinone) biosynthesis enzyme required for lipoprotein metabolim; involved in response to dietary restriction; adversely influences biological rhythms, lifespan and fertility.TABLE OF CONTENTS / OPEN CLOSE ALL PARAGRAPHS SUMMARY
Summary
[Wormbase] clk-1 encodes the C. elegans ortholog of COQ7/CAT5, a highly conserved demethoxyubiquinone (DMQ) hydroxylase that is necessary for the biosynthesis of ubiquinone (coenzyme Q, Q9) from 5-demethoxyubiquinone (DMQ9); in C. elegans, CLK-1 activity is required for normal physiological rates of growth, development, behavior, and aging, as well as for normal brood sizes.
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 3 spliced variants.
AceView synopsis, each blue text links to tables and details Expression: According to AceView, this gene is expressed at very high level, 8.5 times the average gene in this release, only in embryos, L1, L2 and L3 larvae [Kohara cDNAs]. The expression profile for the gene, derived from the proportion of animals at each stage in each Kohara library is: embryos 28%, L1 or L2 larvae 57%, L3 to adult 15%. See the in situ hybridization pattern in Kohara NextDB. The sequence of this gene is defined by 7 cDNA clones and 105 elements defined by RNA-seq, some from l2 (seen 4 times), embryo (2). Alternative mRNA variants and regulation: The gene contains 5 distinct gt-ag introns. Transcription produces 3 alternatively spliced mRNAs. Variant a is transpliced to SL6, SL2, SL3, SL4, b to SL1. There are 2 probable alternative promotors and 4 validated alternative polyadenylation sites (see the diagram). The mRNAs appear to differ by overlapping exons with different boundaries, splicing versus retention of one intron.
Note that mRNA .b was found in vivo, although it is a predicted target of nonsense mediated mRNA decay (NMD). Function: There are 57 articles specifically referring to this gene in PubMed. In addition we point below to 40 abstracts. This gene is associated to a phenotype (CLocK (biological timing) abnormality, maternal rescue, regulates metabolic activity, slow embryonic cell division, SLow growth, extends adult lifespan, reduced fertility, DEfecation Cycle abnormal). Functionally, the gene has been proposed to participate in processes (protein metabolism, ubiquinone biosynthesis). Proteins are expected to localize in various compartments (cytoplasm, mitochondrion). The gene interacts with 13 other genes (APR-1, ARK-1, CTL-1, CTL-2, CUX-7+CLK-2, DAF-2, DAF-16, DSC-4, EAT-2, GRO-1, ITR-1, LET-60, SOD-1). Protein coding potential: The 3 spliced mRNAs putatively encode good proteins, altogether 3 different isoforms (2 complete, 1 partial), some containing Ubiquinone biosynthesis protein COQ7 domain [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 clk-1 maps on chomosome III at position -1.88 (interpolated). In AceView, it covers 1.46 kb, from 5277853 to 5279314 (WS190), on the direct strand. Links to:WormBase, NextDB, RNAiDB.
as Other names: The gene is also known coq-7, in Wormgenes/AceView by its positional name 3G369, in Wormbase by its cosmid.number name ZC395.2, in NextDB, the Nematode expression pattern database, as CEYK5490.
Please choose between the zoomable GIF version., and the HTML5/SVG version.
This diagram shows in true scale the gene on the genome, the mRNAs and the cDNA clones.
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, .c.
or in GIF: .a, .b, .c
[cgc3496] Characterization of a life-extending mutation in age-2, a new aging gene in Caenorhabditis elegans.
[wm99p205] Isolation and Characterization of Suppressors of the C. elegans timing gene clk-1
[wm99p203] Complex alteration of respiration, metabolic potential and ATP stores in long-lived Clk mutants of Caenorhabditis elegans
[wm99p122] A Cytosolic Catalase, CTL-1, Is Necessary For daf-c- and clk-1-dependent Extension of Adult Life-span in C. elegans
[ecwm2000p57] Elongation factor-2 kinase affects Caenorhabditis elegans life span by regulating protein turnover
[wcwm2000p100] The life span gene clk-2 is essential for embryonic development
[wcwm2000p241] The structure/function relationship of clk-1 in the nematode Caenorhabditis elegans
[cgc4374] Patterns of metabolic activity during aging of the wild type and longevity mutants of Caenorhabditis elegans.
[wcwm2000p162] Coenzyme Q and aging in the nematode Caenorhabditis elegans.
[wm2001p314] C. elegans life span is extended by a diet of E. coli lacking coenzyme Q
[wm2001p316] Dramatic changes in chromatin composition associated with dauer formation, caloric restriction, and increased longevity.
[wm2001p332] Effects of ubiquinone metabolism on clk-1 biology
[wm2001p333] Identification of two novel clk mutants
[wm2001p334] Developmental control of coenzyme Q levels - the L2 arrest in clk-1 mutants coincides with an increased reliance on respiratory energy metabolism
[wm2001p335] No reduction of energy metabolism in Clk mutants.
[wm2001p922] Genetic and Phenotypic Analysis of Defecation in clk-1 Mutants.
[wbg17.1p46] Arrhythmicity of the defecation oscillator in lin-42 mutants
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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