Article: An unusual S-adenosylmethionine synthetase gene from dinoflagellate is methylated

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TitleAn unusual S-adenosylmethionine synthetase gene from dinoflagellate is methylated
AuthorsHo, P2
Kong, KF1
Chan, YH2
Tsang, JSH1
Wong, JTY2
Issue Date2007
PublisherBioMed Central Ltd. The Journal's web site is located at http://www.biomedcentral.com/bmcmolbiol/
CitationBmc Molecular Biology, 2007, v. 8 [How to Cite?]
DOI: http://dx.doi.org/10.1186/1471-2199-8-87
AbstractBackground: S-Adenosylmethionine synthetase (AdoMetS) catalyzes the formation of S-Adenosylmethionine (AdoMet), the major methyl group donor in cells. AdoMet-mediated methylation of DNA is known to have regulatory effects on DNA transcription and chromosome structure. Transcription of environmental-responsive genes was demonstrated to be mediated via DNA methylation in dinoflagellates. Results: A full-length cDNA encoding AdoMetS was cloned from the dinoflagellate Crypthecodinium cohnii. Phylogenetic analysis suggests that the CcAdoMetS gene, is associated with the clade of higher plant orthrologues, and not to the clade of the animal orthrologues. Surprisingly, three extra stretches of residues (8 to 19 amino acids) were found on CcAdoMetS, when compared to other members of this usually conserved protein family. Modeled on the bacterial AdeMetS, two of the extra loops are located close to the methionine binding site. Despite this, the CcAdoMetS was able to rescue the corresponding mutant of budding yeast. Southern analysis, coupled with methylation-sensitive and insensitive enzyme digestion of C. cohnii genomic DNA, demonstrated that the AdoMetS gene is itself methylated. The increase in digestibility of methylation-sensitive enzymes on AdoMet synthetase gene observed following the addition of DNA methylation inhibitors L-ethionine and 5-azacytidine suggests the presence of cytosine methylation sites within CcAdoMetS gene. During the cell cycle, both the transcript and protein levels of CcAdoMetS peaked at the G1 phase. L-ethionine was able to delay the cell cycle at the entry of S phase. A cell cycle delay at the exit of G2/M phase was induced by 5-azacytidine. Conclusion: The present study demonstrates a major role of AdoMet-mediated DNA methylation in the regulation of cell proliferation and that the CcAdoMetS gene is itself methylated. © 2007 Ho et al; licensee BioMed Central Ltd.
ISSN1471-2199
2011 Impact Factor: 2.857
2011 SCImago Journal Rankings: 0.398
DOIhttp://dx.doi.org/10.1186/1471-2199-8-87
ISI Accession Number IDWOS:000252380100001
PubMed Central IDPMC2148060
ReferencesReferences in Scopus
DC Field
Value
dc.contributor.authorHo, P
dc.contributor.authorKong, KF
dc.contributor.authorChan, YH
dc.contributor.authorTsang, JSH
dc.contributor.authorWong, JTY
dc.date.accessioned2010-04-12T01:32:33Z
dc.date.available2010-04-12T01:32:33Z
dc.date.issued2007
dc.description.abstractBackground: S-Adenosylmethionine synthetase (AdoMetS) catalyzes the formation of S-Adenosylmethionine (AdoMet), the major methyl group donor in cells. AdoMet-mediated methylation of DNA is known to have regulatory effects on DNA transcription and chromosome structure. Transcription of environmental-responsive genes was demonstrated to be mediated via DNA methylation in dinoflagellates. Results: A full-length cDNA encoding AdoMetS was cloned from the dinoflagellate Crypthecodinium cohnii. Phylogenetic analysis suggests that the CcAdoMetS gene, is associated with the clade of higher plant orthrologues, and not to the clade of the animal orthrologues. Surprisingly, three extra stretches of residues (8 to 19 amino acids) were found on CcAdoMetS, when compared to other members of this usually conserved protein family. Modeled on the bacterial AdeMetS, two of the extra loops are located close to the methionine binding site. Despite this, the CcAdoMetS was able to rescue the corresponding mutant of budding yeast. Southern analysis, coupled with methylation-sensitive and insensitive enzyme digestion of C. cohnii genomic DNA, demonstrated that the AdoMetS gene is itself methylated. The increase in digestibility of methylation-sensitive enzymes on AdoMet synthetase gene observed following the addition of DNA methylation inhibitors L-ethionine and 5-azacytidine suggests the presence of cytosine methylation sites within CcAdoMetS gene. During the cell cycle, both the transcript and protein levels of CcAdoMetS peaked at the G1 phase. L-ethionine was able to delay the cell cycle at the entry of S phase. A cell cycle delay at the exit of G2/M phase was induced by 5-azacytidine. Conclusion: The present study demonstrates a major role of AdoMet-mediated DNA methylation in the regulation of cell proliferation and that the CcAdoMetS gene is itself methylated. © 2007 Ho et al; licensee BioMed Central Ltd.
dc.description.naturepublished_or_final_version
dc.identifier.citationBmc Molecular Biology, 2007, v. 8 [How to Cite?]
DOI: http://dx.doi.org/10.1186/1471-2199-8-87
dc.identifier.citeulike1749126
dc.identifier.doihttp://dx.doi.org/10.1186/1471-2199-8-87
dc.identifier.hkuros143149
dc.identifier.isiWOS:000252380100001
dc.identifier.issn1471-2199
2011 Impact Factor: 2.857
2011 SCImago Journal Rankings: 0.398
dc.identifier.openurl
dc.identifier.pmcidPMC2148060
dc.identifier.pmid17915037
dc.identifier.scopuseid_2-s2.0-37349084292
dc.identifier.urihttp://hdl.handle.net/10722/57302
dc.identifier.volume8
dc.languageeng
dc.publisherBioMed Central Ltd. The Journal's web site is located at http://www.biomedcentral.com/bmcmolbiol/
dc.publisher.placeUnited Kingdom
dc.relation.ispartofBMC Molecular Biology
dc.relation.referencesReferences in Scopus
dc.rightsB M C Molecular Biology. Copyright © BioMed Central Ltd.
dc.rightsCreative Commons: Attribution 3.0 Hong Kong License
dc.subject.meshCell Division - drug effects - physiology
dc.subject.meshDNA Methylation - drug effects
dc.subject.meshDNA, Protozoan - genetics - metabolism
dc.subject.meshDinoflagellida - enzymology - genetics
dc.subject.meshG2 Phase - drug effects - physiology
dc.titleAn unusual S-adenosylmethionine synthetase gene from dinoflagellate is methylated
dc.typeArticle
Author Affiliations
  1. The University of Hong Kong
  2. Hong Kong University of Science and Technology