In JoVE (1)
Articles by Julia Kehr in JoVE
Phloem Sap Sampling from Brassica napus for 3D-PAGE of Protein and Ribonucleoprotein Complexes Steffen Pahlow1, Anna Ostendorp1, Lena Krüßel1, Julia Kehr1 1Molecular Plant Genetics, Universität Hamburg Here we present a protocol to analyze the protein composition of large native protein:protein and protein:nucleic acid complexes from oilseed rape (B. napus) phloem exudate using a 3D polyacrylamide gel electrophoresis (PAGE) approach combining blue native (BN) with two denaturing PAGEs followed by mass spectrometric identification.
Other articles by Julia Kehr on PubMed
Insights into Microalga and Bacteria Interactions of Selected Phycosphere Biofilms Using Metagenomic, Transcriptomic, and Proteomic Approaches Frontiers in Microbiology. | Pubmed ID: 29067007 Microalga are of high relevance for the global carbon cycling and it is well-known that they are associated with a microbiota. However, it remains unclear, if the associated microbiota, often found in phycosphere biofilms, is specific for the microalga strains and which role individual bacterial taxa play. Here we provide experimental evidence that Chlorella saccharophila, Scenedesmus quadricauda, and Micrasterias crux-melitensis, maintained in strain collections, are associated with unique and specific microbial populations. Deep metagenome sequencing, binning approaches, secretome analyses in combination with RNA-Seq data implied fundamental differences in the gene expression profiles of the microbiota associated with the different microalga. Our metatranscriptome analyses indicates that the transcriptionally most active bacteria with respect to key genes commonly involved in plant-microbe interactions in the Chlorella (Trebouxiophyceae) and Scenedesmus (Chlorophyceae) strains belong to the phylum of the α-Proteobacteria. In contrast, in the Micrasterias (Zygnematophyceae) phycosphere biofilm bacteria affiliated with the phylum of the Bacteroidetes showed the highest gene expression rates. We furthermore show that effector molecules known from plant-microbe interactions as inducers for the innate immunity are already of relevance at this evolutionary early plant-microbiome level.
Bioinformatic and Expression Analysis of the Brassica Napus L. Cyclophilins Scientific Reports. May, 2017 | Pubmed ID: 28473712 Cyclophilins (CYPs) are a group of ubiquitous proteins characterized by their ability to bind to the immunosuppressive drug cyclosporin A. The CYP family occurs in a wide range of organisms and contains a conserved peptidyl-prolyl cis/trans isomerase domain. In addition to fulfilling a basic role in protein folding, CYPs may also play diverse important roles, e.g. in protein degradation, mRNA processing, development, and stress responses. We performed a genome-wide database survey and identified a total of 94 CYP genes encoding 91 distinct proteins. Sequence alignment analysis of the putative BnCYP cyclophilin-like domains revealed highly conserved motifs. By using RNA-Seq, we could verify the presence of 77 BnCYP genes under control conditions. To identify phloem-specific BnCYP proteins in a complementary approach, we used LC-MS/MS to determine protein abundances in leaf and phloem extracts. We detected 26 BnCYPs in total with 12 being unique to phloem sap. Our analysis provides the basis for future studies concentrating on the functional characterization of individual members of this gene family in a plant of dual importance: as a crop and a model system for polyploidization and long-distance signalling.