title: Expression patterns and protein structure of a lipid transfer protein END1 from Arabidopsis.
abstract: Arabidopsis END1-LIKE (AtEND1) was identified as a homolog of the barley endosperm-specific gene END1 and provides a model for the study of this class of genes and their products. The END1 is expressed in the endosperm transfer cells (ETC) of grasses. The ETC are responsible for transfer of nutrients from maternal tissues to the developing endosperm. Identification of several ETC-specific genes encoding lipid transfer proteins (LTP), including the END1, provided excellent markers for identification of ETC during seed development. To understand how AtEND1 forms complexes with lipid molecules, a three-dimensional (3D) molecular model was generated and reconciled with AtEND1 function. The spatial and temporal expression patterns of AtEND1 were examined in transgenic Arabidopsis plants transformed with an AtEND1 promoter-GUS fusion construct. The AtEND1 promoter was found to be seed and pollen specific. In contrast to ETC-specific expression of homologous genes in wheat and barley, expression of AtEND1 is less specific. It was observed in ovules and a few gametophytic tissues. A series of AtEND1 promoter deletions fused to coding sequence (CDS) of the uidA were transformed in Arabidopsis and the promoter region responsible for AtEND1 expression was identified. A 163 bp fragment of the promoter was found to be sufficient for both spatial and temporal patterns of expression reflecting that of AtEND1. Our data suggest that AtEND1 could be used as a marker gene for gametophytic tissues and developing endosperm. The role of the gene is unclear but it may be involved in fertilization and/or endosperm cellularization.
authors.affiliation: School of Agriculture, Food and Wine, Plant Genomics Centre, Hartley Grove, Urrbrae, The University of Adelaide, Waite Campus, Glen Osmond, SA, 5064, Australia, ming.li@adelaide.edu.au.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.forename: Sergiy
authors.initials: S
authors.lastname: Lopato
authors.forename: Maria
authors.initials: M
authors.lastname: Hrmova
authors.forename: Melissa
authors.initials: M
authors.lastname: Pickering
authors.forename: Neil
authors.initials: N
authors.lastname: Shirley
authors.forename: Anna M
authors.initials: AM
authors.lastname: Koltunow
authors.forename: Peter
authors.initials: P
authors.lastname: Langridge
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D016000:Cluster Analysis; D003198:Computer Simulation; D018506:Gene Expression Regulation, Plant; D005966:Glucuronidase / Q000378:metabolism; D057927:Hydrophobic and Hydrophilic Interactions; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009928:Organ Specificity / Q000235:genetics; D011401:Promoter Regions, Genetic; D060888:Real-Time Polymerase Chain Reaction; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013997:Time Factors
chemical_list: D029681:Arabidopsis Proteins; D002352:Carrier Proteins; C000602505:END1 protein, Arabidopsis; C030363:lipid transfer protein; D005966:Glucuronidase