title: Characterization of Arabidopsis AtUGT85A and AtGUS gene families and their expression in rapidly dividing tissues.
abstract: In humans, uridine 5'-diphosphate glucuronosyltransferase (UGT) operates in opposition to glucuronidase (GUS) to control activity of diverse metabolites such as hormones by reversible conjugation with glucuronic acid. Previous data revealed that, as in mammals, these enzymes are required for plant life in that a UGT from Pisum sativum (PsUGT1) controls plant development by opposing endogenous GUS activity thereby modulating the duration of the cell cycle. Here we report that a small family of genes (AtUGT85A1, 2, 3, 4, 5, and 7) homologous to pea PsUGT1 exists in the Arabidopsis genome. The AtUGT85A-encoded proteins are predicted to be membrane-associated enzymes. Three genes (AtGUS1, AtGUS2, and AtGUS3) that are homologous to a GUS-encoding gene from Scutellaria baicalensis were identified. The AtGUS-encoded proteins are predicted to be secretory (AtGUS1) and membrane-associated (AtGUS2 and AtGUS3) enzymes. Both AtUGT85A and AtGUS genes, like PsUGT1, exhibit localized, tissue-specific expression, mainly in areas of active cell division with possible involvement in cell cycle regulation.
authors.affiliation: Department of Plant Sciences, Division of Plant Pathology and Microbiology, University of Arizona, Tucson, AZ 85721, USA. hhwoo@email.arizona.edu
authors.forename: Ho-Hyung
authors.initials: HH
authors.lastname: Woo
authors.forename: Byeong Ryong
authors.initials: BR
authors.lastname: Jeong
authors.forename: Ann M
authors.initials: AM
authors.lastname: Hirsch
authors.forename: Martha C
authors.initials: MC
authors.lastname: Hawes
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D002455:Cell Division / Q000235:genetics*; D049109:Cell Proliferation; D005786:Gene Expression Regulation; D017343:Genes, Plant; D005966:Glucuronidase / Q000096:biosynthesis / Q000235:genetics*; D014453:Glucuronosyltransferase / Q000096:biosynthesis / Q000235:genetics*; D006031:Glycosylation; D008969:Molecular Sequence Data; D005810:Multigene Family
chemical_list: D014453:Glucuronosyltransferase; D005966:Glucuronidase