title: The identification and structure of an N-terminal PR domain show that FOG1 is a member of the PRDM family of proteins.
abstract: FOG1 is a transcriptional regulator that acts in concert with the hematopoietic master regulator GATA1 to coordinate the differentiation of platelets and erythrocytes. Despite considerable effort, however, the mechanisms through which FOG1 regulates gene expression are only partially understood. Here we report the discovery of a previously unrecognized domain in FOG1: a PR (PRD-BF1 and RIZ) domain that is distantly related in sequence to the SET domains that are found in many histone methyltransferases. We have used NMR spectroscopy to determine the solution structure of this domain, revealing that the domain shares close structural similarity with SET domains. Titration with S-adenosyl-L-homocysteine, the cofactor product synonymous with SET domain methyltransferase activity, indicated that the FOG PR domain is not, however, likely to function as a methyltransferase in the same fashion. We also sought to define the function of this domain using both pulldown experiments and gel shift assays. However, neither pulldowns from mammalian nuclear extracts nor yeast two-hybrid assays reproducibly revealed binding partners, and we were unable to detect nucleic-acid-binding activity in this domain using our high-diversity Pentaprobe oligonucleotides. Overall, our data demonstrate that FOG1 is a member of the PRDM (PR domain containing proteins, with zinc fingers) family of transcriptional regulators. The function of many PR domains, however, remains somewhat enigmatic for the time being.
authors.affiliation: School of Molecular Bioscience, University of Sydney, Sydney, NSW, Australia.
authors.forename: Molly K
authors.initials: MK
authors.lastname: Clifton
authors.affiliation: School of Molecular Bioscience, University of Sydney, Sydney, NSW, Australia.
authors.forename: Belinda J
authors.initials: BJ
authors.lastname: Westman
authors.affiliation: School of Molecular Bioscience, University of Sydney, Sydney, NSW, Australia.
authors.forename: Sock Yue
authors.initials: SY
authors.lastname: Thong
authors.affiliation: School of Molecular Bioscience, University of Sydney, Sydney, NSW, Australia.
authors.forename: Mitchell R
authors.initials: MR
authors.lastname: O'Connell
authors.affiliation: School of Molecular Bioscience, University of Sydney, Sydney, NSW, Australia.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Webster
authors.affiliation: School of Molecular Bioscience, University of Sydney, Sydney, NSW, Australia.
authors.forename: Nicholas E
authors.initials: NE
authors.lastname: Shepherd
authors.affiliation: School of Molecular Bioscience, University of Sydney, Sydney, NSW, Australia.
authors.forename: Kate G
authors.initials: KG
authors.lastname: Quinlan
authors.affiliation: School of Molecular Bioscience, University of Sydney, Sydney, NSW, Australia.
authors.forename: Merlin
authors.initials: M
authors.lastname: Crossley
authors.affiliation: Division of Hematology, The Children's Hospital of Philadelphia, The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.
authors.forename: Gerd A
authors.initials: GA
authors.lastname: Blobel
authors.affiliation: School of Molecular Bioscience, University of Sydney, Sydney, NSW, Australia.
authors.forename: Joel P
authors.initials: JP
authors.lastname: Mackay
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D045744:Cell Line, Tumor; D017124:Conserved Sequence; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D006801:Humans; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry* / Q000235:genetics; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D012435:S-Adenosylhomocysteine / Q000737:chemistry; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics
chemical_list: D009687:Nuclear Proteins; D020033:Protein Isoforms; D011994:Recombinant Proteins; D014157:Transcription Factors; C498432:ZFPM1 protein, human; C107310:Zfpm1 protein, mouse; D012435:S-Adenosylhomocysteine