title: Functional diversification of maize RNA polymerase IV and V subtypes via alternative catalytic subunits.
abstract: Unlike nuclear multisubunit RNA polymerases I, II, and III, whose subunit compositions are conserved throughout eukaryotes, plant RNA polymerases IV and V are nonessential, Pol II-related enzymes whose subunit compositions are still evolving. Whereas Arabidopsis Pols IV and V differ from Pol II in four or five of their 12 subunits, respectively, and differ from one another in three subunits, proteomic analyses show that maize Pols IV and V differ from Pol II in six subunits but differ from each other only in their largest subunits. Use of alternative catalytic second subunits, which are nonredundant for development and paramutation, yields at least two subtypes of Pol IV and three subtypes of Pol V in maize. Pol IV/Pol V associations with MOP1, RMR1, AGO121, Zm_DRD1/CHR127, SHH2a, and SHH2b extend parallels between paramutation in maize and the RNA-directed DNA methylation pathway in Arabidopsis.
authors.affiliation: Department of Biology and Department of Molecular and Cellular Biochemistry, Indiana University, 915 E. Third Street, Bloomington, IN 47405, USA; Howard Hughes Medical Institute, Indiana University, Bloomington, IN 47405, USA.
authors.forename: Jeremy R
authors.initials: JR
authors.lastname: Haag
authors.affiliation: Monsanto Company, 700 West Chesterfield Parkway, Chesterfield, MO 63017, USA.
authors.forename: Brent
authors.initials: B
authors.lastname: Brower-Toland
authors.affiliation: Monsanto Company, 700 West Chesterfield Parkway, Chesterfield, MO 63017, USA.
authors.forename: Elysia K
authors.initials: EK
authors.lastname: Krieger
authors.affiliation: BIO5 Institute, Department of Plant Sciences, University of Arizona, Tucson, AZ 85719, USA.
authors.forename: Lyudmila
authors.initials: L
authors.lastname: Sidorenko
authors.affiliation: Pacific Northwest National Laboratory, Richland, WA 99352, USA.
authors.forename: Carrie D
authors.initials: CD
authors.lastname: Nicora
authors.affiliation: Pacific Northwest National Laboratory, Richland, WA 99352, USA.
authors.forename: Angela D
authors.initials: AD
authors.lastname: Norbeck
authors.affiliation: Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA.
authors.forename: Andre
authors.initials: A
authors.lastname: Irsigler
authors.affiliation: Monsanto Company, 700 West Chesterfield Parkway, Chesterfield, MO 63017, USA.
authors.forename: Huachun
authors.initials: H
authors.lastname: LaRue
authors.affiliation: BIO5 Institute, Department of Plant Sciences, University of Arizona, Tucson, AZ 85719, USA.
authors.forename: Jan
authors.initials: J
authors.lastname: Brzeski
authors.affiliation: Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA.
authors.forename: Karen
authors.initials: K
authors.lastname: McGinnis
authors.affiliation: Monsanto Company, 700 West Chesterfield Parkway, Chesterfield, MO 63017, USA.
authors.forename: Sergey
authors.initials: S
authors.lastname: Ivashuta
authors.affiliation: Pacific Northwest National Laboratory, Richland, WA 99352, USA.
authors.forename: Ljiljana
authors.initials: L
authors.lastname: Pasa-Tolic
authors.affiliation: BIO5 Institute, Department of Plant Sciences, University of Arizona, Tucson, AZ 85719, USA.
authors.forename: Vicki L
authors.initials: VL
authors.lastname: Chandler
authors.affiliation: Department of Biology and Department of Molecular and Cellular Biochemistry, Indiana University, 915 E. Third Street, Bloomington, IN 47405, USA; Howard Hughes Medical Institute, Indiana University, Bloomington, IN 47405, USA. Electronic address: cpikaard@indiana.edu.
authors.forename: Craig S
authors.initials: CS
authors.lastname: Pikaard
mesh_terms: D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D020134:Catalytic Domain; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D010802:Phylogeny; D030821:Plants, Genetically Modified / Q000378:metabolism; D014158:Transcription, Genetic; D003313:Zea mays / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D012321:DNA-Directed RNA Polymerases