title: Characterization and expression of four proline-rich cell wall protein genes in Arabidopsis encoding two distinct subsets of multiple domain proteins.
abstract: We have characterized the molecular organization and expression of four proline-rich protein genes from Arabidopsis (AtPRPs). These genes predict two classes of cell wall proteins based on DNA sequence identity, repetitive motifs, and domain organization. AtPRP1 and AtPRP3 encode proteins containing an N-terminal PRP-like domain followed by a C-terminal domain that is biased toward P, T, Y, and K. AtPRP2 and AtPRP4 represent a second, novel group of PRP genes that encode two-domain proteins containing a non-repetitive N-terminal domain followed by a PRP-like region rich in P, V, K, and C. Northern hybridization analysis indicated that AtPRP1 and AtPRP3 are exclusively expressed in roots, while transcripts encoding AtPRP2 and AtPRP4 were most abundant in aerial organs of the plant. Histochemical analyses of promoter/beta-glucuronidase fusions localized AtPRP3 expression to regions of the root containing root hairs. AtPRP2 and AtPRP4 expression was detected in expanding leaves, stems, flowers, and siliques. In addition, AtPRP4 expression was detected in stipules and during the early stages of lateral root formation. These studies support a model for involvement of PRPs in specifying cell-type-specific wall structures, and provide the basis for a genetic approach to dissect the function of PRPs during growth and development.
authors.affiliation: Department of Botany and Agricultural Biochemistry, University of Vermont, Burlington, Vermont 05405, USA.
authors.forename: T J
authors.initials: TJ
authors.lastname: Fowler
authors.forename: C
authors.initials: C
authors.lastname: Bernhardt
authors.forename: M L
authors.initials: ML
authors.lastname: Tierney
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins; D001483:Base Sequence; D002473:Cell Wall / Q000378:metabolism; D003001:Cloning, Molecular; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010455:Peptides / Q000737:chemistry / Q000235:genetics*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics*; D011392:Proline; D055232:Proline-Rich Protein Domains; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D029681:Arabidopsis Proteins; D010455:Peptides; D010940:Plant Proteins; C403250:proline-rich protein, Arabidopsis; D011392:Proline