DAWDLE Interacts with DICER-LIKE Proteins to Mediate Small RNA Biogenesis.

DAWDLE (DDL) is a conserved forkhead-associated (FHA) domain-containing protein with essential roles in plant development and immunity. It acts in the biogenesis of microRNAs (miRNAs) and endogenous small interfering RNAs (siRNAs), which regulate gene expression at the transcriptional and/or posttranscriptional levels. However, the functional mechanism of DDL and its impact on exogenous siRNAs remain elusive.

Genome-Wide Analysis of MicroRNA-Regulated Transcripts.

MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression by either degrading transcripts or repressing translation . Over the past decade the significance of miRNAs has been unraveled by the characterization of their involvement in crucial cellular functions and the development of disease. However, continued progress in understanding the endogenous importance of miRNAs, as well as their potential uses as therapeutic tools, has been hindered by the difficulty of positively identifying miRNA targets.

DVL genes play a role in the coordination of socket cell recruitment and differentiation.

Specialized plant cells arise from undifferentiated cells through a series of developmental steps. The decision to enter into a certain differentiation pathway depends in many cases on signals from neighbouring cells. The ability of cells to engage in short-range intercellular communication permits the coordination of cell actions necessary in many developmental processes.

Fiber loop ringdown DNA and bacteria sensors.

We report a new type of refractive index-based biosensor using a fiber loop ringdown evanescent field (FLRD-EF) sensing scheme, in which the sensing signal is a time constant and detection sensitivity is enhanced by the multipass nature of the ringdown technique. Bulk index-based detections of three different single strand DNAs and one type of bacteria are demonstrated for the FLRD-EF sensors that utilize a partially-etched single mode fiber as the sensor head. Stepwise coating of the sensor head with poly-L-lysine and a probe DNA has enabled surface index-based label-free target DNA sensing.

14-3-3 and FHA domains mediate phosphoprotein interactions.

Many aspects of plant growth and development require specific protein interactions to carry out biochemical and cellular functions. Several proteins mediate these interactions, two of which specifically recognize phosphoproteins: 14-3-3 proteins and proteins with FHA domains. These are the only phosphobinding domains identified in plants.

Regulation of floral organ abscission in Arabidopsis thaliana.

Abscission is a developmental program that results in the active shedding of infected or nonfunctional organs from a plant body. Here, we establish a signaling pathway that controls abscission in Arabidopsis thaliana from ligand, to receptors, to downstream effectors. Loss of function mutations in Inflorescence Deficient in Abscission (IDA), which encodes a predicted secreted small protein, the receptor-like protein kinases HAESA (HAE) and HAESA-like 2 (HSL2), the Mitogen-Activated Protein Kinase Kinase 4 (MKK4) and MKK5, and a dominant-negative form of Mitogen-Activated Protein Kinase 6 (MPK6) in a mpk3 mutant background all have abscission-defective phenotypes.

The FHA domain proteins DAWDLE in Arabidopsis and SNIP1 in humans act in small RNA biogenesis.

Proteins containing the forkhead-associated domain (FHA) are known to act in biological processes such as DNA damage repair, protein degradation, and signal transduction. Here we report that DAWDLE (DDL), an FHA domain-containing protein in Arabidopsis, acts in the biogenesis of miRNAs and endogenous siRNAs. Unlike mutants of genes known to participate in the processing of miRNA precursors, such as dcl1, hyponastic leaves1, and serrate, ddl mutants show reduced levels of pri-miRNAs as well as mature miRNAs.

Molecular characterisation of the STRUBBELIG-RECEPTOR FAMILY of genes encoding putative leucine-rich repeat receptor-like kinases in Arabidopsis thaliana.

Background: Receptor-like kinases are a prominent class of surface receptors that regulate many aspects of the plant life cycle. Despite recent advances the function of most receptor-like kinases remains elusive. Therefore, it is paramount to investigate these receptors.

DAWDLE, a forkhead-associated domain gene, regulates multiple aspects of plant development.

Phosphoprotein-binding domains are found in many different proteins and specify protein-protein interactions critical for signal transduction pathways. Forkhead-associated (FHA) domains bind phosphothreonine and control many aspects of cell proliferation in yeast (Saccharomyces cerevisiae) and animal cells. The Arabidopsis (Arabidopsis thaliana) protein kinase-associated protein phosphatase includes a FHA domain that mediates interactions with receptor-like kinases, which in turn regulate a variety of signaling pathways involved in plant growth and pathogen responses.

STRUBBELIG defines a receptor kinase-mediated signaling pathway regulating organ development in Arabidopsis.

An open question remains as to what coordinates cell behavior during organogenesis, permitting organs to reach their appropriate size and shape. The Arabidopsis gene STRUBBELIG (SUB) defines a receptor-mediated signaling pathway in plants. SUB encodes a putative leucine-rich repeat transmembrane receptor-like kinase.

Functional genomics of protein kinases in plants.

Functional genomics has revolutionised the way that scientists approach biological questions, allowing for the comprehensive characterisation of the function of related proteins encoded in a genome. The sequencing of the genome of the model system Arabidopsis thaliana has enabled the beginning of functional genomics and the study of protein kinase families in plants. The large family of genes encoding protein kinases is a primary target of functional genomics studies in plants due to their importance in diverse physiological processes.