Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
Front Genet
2012 Mar 14;3:304. doi: 10.3389/fgene.2012.00304.
Show Gene links
Show Anatomy links
A comparative approach to understanding tissue-specific expression of uncoupling protein 1 expression in adipose tissue.
Shore A
,
Emes RD
,
Wessely F
,
Kemp P
,
Cillo C
,
D'Armiento M
,
Hoggard N
,
Lomax MA
.
???displayArticle.abstract???
The thermoregulatory function of brown adipose tissue (BAT) is due to the tissue-specific expression of uncoupling protein 1 (UCP1) which is thought to have evolved in early mammals. We report that a CpG island close to the UCP1 transcription start site is highly conserved in all 29 vertebrates examined apart from the mouse and xenopus. Using methylation sensitive restriction digest and bisulfite mapping we show that the CpG island in both the bovine and human is largely un-methylated and is not related to differences in UCP1 expression between white and BAT. Tissue-specific expression of UCP1 has been proposed to be regulated by a conserved 5' distal enhancer which has been reported to be absent in marsupials. We demonstrate that the enhancer, is also absent in five eutherians as well as marsupials, monotremes, amphibians, and fish, is present in pigs despite UCP1 having become a pseudogene, and that absence of the enhancer element does not relate to BAT-specific UCP1 expression. We identify an additional putative 5' regulatory unit which is conserved in 14 eutherian species but absent in other eutherians and vertebrates, but again unrelated to UCP1 expression. We conclude that despite clear evidence of conservation of regulatory elements in the UCP1 5' untranslated region, this does not appear to be related to species or tissues-specific expression of UCP1.
Figure 1. Expression and UCP1 promoter percentage CpG methylation. (A) bovine UCP1 mRNA expression by qRTPCR. Methylation sensitive restriction digest determination of (B) bovine, (C) human CpG islands, (D) human enhancer, and (E) bisulfite mapping determination of the percentage methylation of 12 CpGs within the bovine CpG island, in adipose tissues and liver. UCP1 mRNA (A) is expressed relative to ribosomal 18S mRNA. The data are presented as a percentage methylation compared to each respective mock methylated sample for the (B) bovine 288âbp (â¡) and the 407âbp (â ) products and (C) human 173âbp (â¡) and the 426âbp (â ) products and (D) human enhancer (see Materials and Methods). The amount of UCP1 promoter DNA was quantified by qPCR relative to ribosomal 18S DNA. (E) CpG dinucleotide methylation in the Ucp1 proximal promoter in newborn bovine brown (â¡) and subcutaneous white adipose tissue (â ), and liver (). For comparison, values for the mouse enhancer (ENH) BAT, WAT, and liver are presented. DNA was extracted, bisulfite modified, amplified by PCR, and pyrosequenced to determine CpG methylation over positions 1â12 of the Ucp1 promoter (see Materials and Methods). Missing liver values are due to failed analyses. Values are meansâ±âSEM from at least three replicates except for (D) which represents the average of duplicatesâ±âSD *** BAT significantly greater than other tissues (pâ<â0.001).
Figure 2. Map of the relative positions of the conserved enhancer, putative regulatory region and predicted CpG island in the UCP1 promoter of 29 species. All genes are shown in 5â²â3â² orientation. Arrow represent the region of the UCP1 coding sequence. Differences in arrow length are likely to reflect relative differences in intron sizes.
Figure A1. Gene synteny around the UCP1 locus. Relative positions of UCP1 orthologs in four representative species showing conservation of synteny. Positions of conserved upstream regions and predicted CpG islands are shown. Gaps in current genome build are shown as hashed boxes. For details see Table A2.
Figure A2. Evolutionary conservation of the regions of the UCP1 5â² UTR enhancer and putative regulatory region. Pairwise comparison of cow-mouse (A) and cow-human (B) genomic DNA 5âKb upstream of UCP1 gene rVISTA (Loots et al., 2002) using the AVID alignment algorithm (Bray et al., 2003). Conserved regions (>70% conserved in 100âbp window are shaded). A highly conserved peak is visible at approximately â3.6âKb within the conserved enhancer region. A second conserved region approximately â1.1 to â1.6âkb is conserved between cattle and human but is missing in the mouse genome. Within peaks of sequence similarity are a number of conserved transcription factor binding sites of interest (CEBP, CREB, DR1, DR3, DR4, PPAR) marked with the bars.
Figure A3. Partial alignment of conserved enhancer region in 20 vertebrate species, approximately â3800âbp of human UCP1. For genome coordinates and full alignment, see Appendix.
Figure A4. (A) Alignment of conserved enhancer region in human, bovine, rat, and mouse, approximately â3800âbp of human UCP1. Positions of known transcription factor binding sites taken from Jastroch et al. (2008) (B) Partial alignment of conserved putative regulatory region (PRR) approximately â2200 to â2700âbp of human UCP1. For genome coordinates and full alignment, see Appendix.
Figure A5. Sequence of the conserved enhancer region in 20 vertebrate species.
Berg,
The uncoupling protein 1 gene (UCP1) is disrupted in the pig lineage: a genetic explanation for poor thermoregulation in piglets.
2006, Pubmed
Berg,
The uncoupling protein 1 gene (UCP1) is disrupted in the pig lineage: a genetic explanation for poor thermoregulation in piglets.
2006,
Pubmed
Bray,
AVID: A global alignment program.
2003,
Pubmed
Cannon,
Brown adipose tissue: function and physiological significance.
2004,
Pubmed
Cassard-Doulcier,
A 211-bp enhancer of the rat uncoupling protein-1 (UCP-1) gene controls specific and regulated expression in brown adipose tissue.
1998,
Pubmed
Clark,
High sensitivity mapping of methylated cytosines.
1994,
Pubmed
del Mar Gonzalez-Barroso,
Transcriptional activation of the human ucp1 gene in a rodent cell line. Synergism of retinoids, isoproterenol, and thiazolidinedione is mediated by a multipartite response element.
2000,
Pubmed
Gardiner-Garden,
CpG islands in vertebrate genomes.
1987,
Pubmed
Gavrilova,
[Genetic mapping of the ilv7434 mutation providing threonine deaminase resistance to isoleucine inhibition in Escherichia coli].
1988,
Pubmed
Hughes,
Molecular evolution of UCP1 and the evolutionary history of mammalian non-shivering thermogenesis.
2009,
Pubmed
Jastroch,
Marsupial uncoupling protein 1 sheds light on the evolution of mammalian nonshivering thermogenesis.
2008,
Pubmed
Karamanlidis,
C/EBPbeta reprograms white 3T3-L1 preadipocytes to a Brown adipocyte pattern of gene expression.
2007,
Pubmed
Karamitri,
Combinatorial transcription factor regulation of the cyclic AMP-response element on the Pgc-1alpha promoter in white 3T3-L1 and brown HIB-1B preadipocytes.
2009,
Pubmed
Kiskinis,
RIP140 directs histone and DNA methylation to silence Ucp1 expression in white adipocytes.
2007,
Pubmed
Kitao,
Molecular cloning and tissue distribution of uncoupling protein 1 (UCP1) in plateau pika (Ochotona dauurica).
2007,
Pubmed
Klingenspor,
An ancient look at UCP1.
2008,
Pubmed
Liu,
Uncoupling protein mRNA, mitochondrial GTP-binding, and T4 5'-deiodinase activity of brown adipose tissue in Daurian ground squirrel during hibernation and arousal.
1998,
Pubmed
Livak,
Analysis of relative gene expression data using real-time quantitative PCR and the 2(-Delta Delta C(T)) Method.
2001,
Pubmed
Lomax,
Ontogenic loss of brown adipose tissue sensitivity to beta-adrenergic stimulation in the ovine.
2007,
Pubmed
Loncar,
Immunoelectron microscopical studies on synthesis and localization of uncoupling protein in brown adipocytes: evidence for cotranslational transport of uncoupling protein into mitochondria.
1990,
Pubmed
Loots,
rVista for comparative sequence-based discovery of functional transcription factor binding sites.
2002,
Pubmed
McKinnon,
Pancreatic duodenal homeobox-1, PDX-1, a major regulator of beta cell identity and function.
2001,
Pubmed
Mzilikazi,
The molecular and biochemical basis of nonshivering thermogenesis in an African endemic mammal, Elephantulus myurus.
2007,
Pubmed
Nedergaard,
Unexpected evidence for active brown adipose tissue in adult humans.
2007,
Pubmed
Rim,
Regulatory motifs for CREB-binding protein and Nfe2l2 transcription factors in the upstream enhancer of the mitochondrial uncoupling protein 1 gene.
2002,
Pubmed
Rim,
Sequestration of thermogenic transcription factors in the cytoplasm during development of brown adipose tissue.
2004,
Pubmed
Rothwell,
Thermogenic capacity and brown adipose tissue activity in the common marmoset.
1985,
Pubmed
Sakurai,
In vitro modeling of paraxial and lateral mesoderm differentiation reveals early reversibility.
2006,
Pubmed
Shore,
Role of Ucp1 enhancer methylation and chromatin remodelling in the control of Ucp1 expression in murine adipose tissue.
2010,
Pubmed
Suzuki,
Cloning of putative uncoupling protein 1 cDNA in a cold-intolerant mammal, the house musk shrew (Suncus murinus).
2006,
Pubmed
Symonds,
Maternal and environmental influences on thermoregulation in the neonate.
1992,
Pubmed
Xue,
Transcriptional synergy and the regulation of Ucp1 during brown adipocyte induction in white fat depots.
2005,
Pubmed
