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Daphne R Goring

Publications and source records attributed to Daphne R Goring.

7 recordsLinked to original sources
PubMed2006

Multifunctional arm repeat domains in plants.

Arm repeat domains are composed of multiple 42 amino acid Arm repeats and are found in the proteomes of all eukaryotic organisms. The Arm repeat domain is a highly conserved right-handed super helix of alpha-helices involved in protein-protein interactions. The well-characterized Arm repeat proteins in animal and plants are known to function in diverse cellular processes including signal transduction, cytoskeletal regulation, nuclear import, transcriptional regulation, and ubiquitination. While Arm repeat domains are found in all eukaryotes, plants have evolved some unique domain organizations, such as the U-box and Arm repeat domain combination, with specialized functions. The plant-specific U-box/Arm repeat proteins are the largest family of Arm repeat proteins in all the genomes surveyed, and more recent data have implicated these proteins as E3 ubiquitin ligases. While functions have not been assigned for most of the plant Arm repeat proteins, recent studies have demonstrated their importance in multiple processes such as self-incompatibility, hormone signaling, and disease resistance.

Arabidopsis↗
PubMed2004

Antisense suppression of thioredoxin h mRNA in Brassica napus cv. Westar pistils causes a low level constitutive pollen rejection response.

In Brassica , the thioredoxin h proteins, THL1 and THL2, were previously found to be potential inhibitors of the S receptor kinase (SRK) in the Brassica self-incompatibility response. To investigate the biological roles of THL1 and THL2 in pollen-pistil interactions, the stigma-specific SLR1 promoter was used to drive antisense THL1/2 expression in Brassica napus cv. Westar. This cultivar is normally compatible, but antisense suppression of THL1/2 led to a low level constitutive rejection of all Brassica napus pollen tested. Fluorescence microscopy revealed that the pollen rejection was a typical Brassica self-incompatibility rejection response with reduced pollen adhesion, germination and pollen tube growth. In addition, Westar was found to express the SLG(15) and SRK(15) proteins which may be the target of regulation by THL1 and THL2. Thus, these results indicate that the THL1 and THL2 are required for full pollen acceptance in B. napus cv. Westar.

Blotting, Northern↗
PubMed2004

A comprehensive expression analysis of the Arabidopsis proline-rich extensin-like receptor kinase gene family using bioinformatic and experimental approaches.

The Arabidopsis proline-rich extensin-like receptor kinase (PERK) family consists of 15 predicted receptor kinases. A comprehensive expression analysis was undertaken to identify overlapping and unique expression patterns within this family relative to their phylogeny. Three different approaches were used to study AtPERK gene family expression, and included analyses of the EST, MPSS and NASCArrays databases as well as experimental RNA blot analyses. Some of the AtPERK members were identified as tissue-specific genes while others were more broadly expressed. While in some cases there was a good association between these different expression patterns and the position of the AtPERK members in the kinase phylogeny, in other cases divergence of expression patterns was seen. The PERK expression data identified by the bioinformatics and experimental approaches were found generally to show similar trends and supported the use of data from large-scale expression studies for obtaining preliminary expression data. Thus, the bioinformatics survey for ESTs and microarrays is a powerful comprehensive approach for obtaining a genome-wide view of genes in a multigene family.

Arabidopsis↗
PubMed2003

A large complement of the predicted Arabidopsis ARM repeat proteins are members of the U-box E3 ubiquitin ligase family.

The Arabidopsis genome was searched to identify predicted proteins containing armadillo (ARM) repeats, a motif known to mediate protein-protein interactions in a number of different animal proteins. Using domain database predictions and models generated in this study, 108 Arabidopsis proteins were identified that contained a minimum of two ARM repeats with the majority of proteins containing four to eight ARM repeats. Clustering analysis showed that the 108 predicted Arabidopsis ARM repeat proteins could be divided into multiple groups with wide differences in their domain compositions and organizations. Interestingly, 41 of the 108 Arabidopsis ARM repeat proteins contained a U-box, a motif present in a family of E3 ligases, and these proteins represented the largest class of Arabidopsis ARM repeat proteins. In 14 of these U-box/ARM repeat proteins, there was also a novel conserved domain identified in the N-terminal region. Based on the phylogenetic tree, representative U-box/ARM repeat proteins were selected for further study. RNA-blot analyses revealed that these U-box/ARM proteins are expressed in a variety of tissues in Arabidopsis. In addition, the selected U-box/ARM proteins were found to be functional E3 ubiquitin ligases. Thus, these U-box/ARM proteins represent a new family of E3 ligases in Arabidopsis.

Amino Acid Motifs↗
PubMed2003

ARC1 is an E3 ubiquitin ligase and promotes the ubiquitination of proteins during the rejection of self-incompatible Brassica pollen.

ARC1 is a novel U-box protein required in the Brassica pistil for the rejection of self-incompatible pollen; it functions downstream of the S receptor kinase (SRK). Here, we show that ARC1 has E3 ubiquitin ligase activity and contains several motifs that influence its subcellular localization. ARC1 can shuttle between the nucleus, cytosol, and proteasome/COP9 signalosome (CSN) when expressed in tobacco BY-2 suspension-cultured cells. However, ARC1 localization to the proteasome/CSN occurs only in the presence of an active SRK. In the pistil, ubiquitinated protein levels increase specifically with incompatible pollinations, but they do not change in ARC1 antisense-suppressed pistils. In addition, inhibition of the proteasomal proteolytic activity disrupts the self-incompatibility response. We propose that ARC1 promotes the ubiquitination and proteasomal degradation of compatibility factors in the pistil, which in turn leads to pollen rejection.

Arabidopsis Proteins↗
PubMed2002

The proline-rich, extensin-like receptor kinase-1 (PERK1) gene is rapidly induced by wounding.

We report the isolation and characterization of PERKI (Proline Extensin-like Receptor Kinase 1), a novel plant RLK from Brassica napus that is predicted to consist of a proline-rich extracellular domain with sequence similarity to extensins, a transmembrane region, and a catalytic domain possessing serine/threonine kinase activity. Database searches with the predicted PERK1 amino acid sequence also led to the identification of a predicted family of related genes in the Arabidopsis genome. Using biolistic bombardment of onion epidermal cells, we have shown that a PERK1-GFP fusion is localized to the plasma membrane as predicted for a receptor kinase. Given the similarity of PERK1's extracellular domain to extensins, a possible role in plant defense responses was investigated by treating B. napus tissue with mechanical stresses and infection with the fungal pathogen, Sclerotinia sclerotiorum. Various wounding stimuli resulted in a dramatic and rapid accumulation of PERK1 mRNA. Levels of PERK1 mRNA also increased moderately in response to infection by the fungal pathogen S. sclerotiorum. Given the kinetics of PERK1 mRNA accumulation in response to these treatments, PERK1 may be involved early on in the general perception and response to a wound and/or pathogen stimulus.

Amino Acid Sequence↗