title: The Caenorhabditis elegans sirtuin gene, sir-2.1, is widely expressed and induced upon caloric restriction.
abstract: BACKGROUND
  As in yeast, flies and mammals, over-expression of the Caenorhabditis elegans sirtuin gene sir-2.1 leads to extension of lifespan and deletion of the gene shortens lifespan. The sir-2.1 gene, however, is located in an operon, an organization not taken into account in previous studies of this gene's expression.
  
  
  METHODS
  Recombineering allowed insertion of both a mCherry and a gfp reporter gene precisely at the end of the two protein-coding regions of the 4.5kb sir-2.1 operon within a 29.3kb genomic DNA fosmid clone.
  
  
  CONCLUSIONS
  In C. elegans transgenic for this recombineered fosmid, with abundant food, the sir-2.1::mCherry distribution indicated that sir-2.1 is indeed expressed in the hypodermis and many nerve cells, as previously described, but also in the intestine and in muscles. This broader expression of sir-2.1, which would fit with an expectation that SIR2.1 function in influencing lifespan might be required in most cell types, arises from transcription starting with the gene upstream of sir-2.1 in the operon. Importantly, the expression of both genes in the operon increases upon starvation, this induction also depending on the operon promoter. Furthermore, SIR-2.1::mCherry undergoes a dynamic subcellular relocalization through starvation.
authors.affiliation: Institute of Integrative and Comparative Biology, Faculty of Biological Sciences, The University of Leeds, Woodhouse Lane, Leeds LS2 9JT, UK. s.bamps@leeds.ac.uk
authors.forename: Sophie
authors.initials: S
authors.lastname: Bamps
authors.forename: Julia
authors.initials: J
authors.lastname: Wirtz
authors.forename: Fiona R
authors.initials: FR
authors.lastname: Savory
authors.forename: Duncan
authors.initials: D
authors.lastname: Lake
authors.forename: Ian A
authors.initials: IA
authors.lastname: Hope
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics* / Q000502:physiology; D031204:Caloric Restriction; D004032:Diet; D005508:Food Deprivation / Q000502:physiology; D015870:Gene Expression; D049452:Green Fluorescent Proteins / Q000235:genetics; D007413:Intestinal Mucosa / Q000378:metabolism; D008136:Longevity; D009132:Muscles / Q000378:metabolism; D009876:Operon / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics; D037761:Sirtuins / Q000235:genetics* / Q000502:physiology
chemical_list: D029742:Caenorhabditis elegans Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; C507014:SIR-2.1 protein, C elegans; D037761:Sirtuins