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

TitleAn unusual S-adenosylmethionine synthetase gene from dinoflagellate is methylated
Authors
Issue Date2007
PublisherBioMed Central Ltd. The Journal's web site is located at http://www.biomedcentral.com/bmcmolbiol/
Citation
Bmc Molecular Biology, 2007, v. 8 How to Cite?
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.
Persistent Identifierhttp://hdl.handle.net/10722/57302
ISSN
2014 Impact Factor: 2.194
2014 SCImago Journal Rankings: 1.032
PubMed Central ID
ISI Accession Number ID
References

 

DC FieldValueLanguage
dc.contributor.authorHo, Pen_HK
dc.contributor.authorKong, KFen_HK
dc.contributor.authorChan, YHen_HK
dc.contributor.authorTsang, JSHen_HK
dc.contributor.authorWong, JTYen_HK
dc.date.accessioned2010-04-12T01:32:33Z-
dc.date.available2010-04-12T01:32:33Z-
dc.date.issued2007en_HK
dc.identifier.citationBmc Molecular Biology, 2007, v. 8en_HK
dc.identifier.issn1471-2199en_HK
dc.identifier.urihttp://hdl.handle.net/10722/57302-
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.en_HK
dc.languageengen_HK
dc.publisherBioMed Central Ltd. The Journal's web site is located at http://www.biomedcentral.com/bmcmolbiol/en_HK
dc.relation.ispartofBMC Molecular Biologyen_HK
dc.rightsB M C Molecular Biology. Copyright © BioMed Central Ltd.en_HK
dc.rightsCreative Commons: Attribution 3.0 Hong Kong License-
dc.subject.meshCell Division - drug effects - physiologyen_HK
dc.subject.meshDNA Methylation - drug effectsen_HK
dc.subject.meshDNA, Protozoan - genetics - metabolismen_HK
dc.subject.meshDinoflagellida - enzymology - geneticsen_HK
dc.subject.meshG2 Phase - drug effects - physiologyen_HK
dc.titleAn unusual S-adenosylmethionine synthetase gene from dinoflagellate is methylateden_HK
dc.typeArticleen_HK
dc.identifier.openurlhttp://library.hku.hk:4550/resserv?sid=HKU:IR&issn=1471-2199&volume=8 article no. 87&spage=&epage=&date=2007&atitle=An+unusual+S-adenosylmethionine+synthetase+gene+from+dinoflagellates+is+methylateden_HK
dc.identifier.emailTsang, JSH: jshtsang@hku.hken_HK
dc.identifier.authorityTsang, JSH=rp00792en_HK
dc.description.naturepublished_or_final_versionen_HK
dc.identifier.doi10.1186/1471-2199-8-87en_HK
dc.identifier.pmid17915037en_HK
dc.identifier.pmcidPMC2148060en_HK
dc.identifier.scopuseid_2-s2.0-37349084292en_HK
dc.identifier.hkuros143149-
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-37349084292&selection=ref&src=s&origin=recordpageen_HK
dc.identifier.volume8en_HK
dc.identifier.eissn1471-2199-
dc.identifier.isiWOS:000252380100001-
dc.publisher.placeUnited Kingdomen_HK
dc.identifier.scopusauthoridHo, P=23094371300en_HK
dc.identifier.scopusauthoridKong, KF=7102579633en_HK
dc.identifier.scopusauthoridChan, YH=14066947500en_HK
dc.identifier.scopusauthoridTsang, JSH=7102483508en_HK
dc.identifier.scopusauthoridWong, JTY=24467064200en_HK
dc.identifier.citeulike1749126-

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