Regulation of developmental gatekeeping and cell fate transition by the calpain protease DEK1 in Physcomitrium patens.

Calpains are cysteine proteases that control cell fate transitions whose loss of function causes severe, pleiotropic phenotypes in eukaryotes. Although mainly considered as modulatory proteases, human calpain targets are directed to the N-end rule degradation pathway. Several such targets are transcription factors, hinting at a gene-regulatory role.

An autoactive gene causes dwarfism in wheat.

Semidwarfing genes have greatly increased wheat yields globally, yet the widely used gibberellin (GA)-insensitive genes and have disadvantages for seedling emergence. Use of the GA-sensitive semidwarfing gene avoids this pleiotropic effect. Here, we show that encodes a () gene.

Transient expression of fluorescently tagged proteins in developing maize aleurone cells.

Expressing transgenes in the endosperm of cereals by developing stably transformed lines is an expensive and labor-intensive process. An alternative that is less expensive and faster is to express the transgenes transiently. We describe here a detailed protocol to express transiently genes in maize aleurone cells by biolistic bombardment of cultured developing endosperms.

The Modular Control of Cereal Endosperm Development.

Expansion of the human population demands a significant increase in cereal production. The main component of cereal grains is endosperm, a body of starchy endosperm (SE) cells surrounded by aleurone (AL) cells with transfer cells (TC) at the base and embryo surrounding (ESR) cells adjacent to the embryo. The data reviewed here emphasize the modular nature of endosperm by first suggesting that sucrose promotes development of the fertilized triploid endosperm cell.

DEK1 displays a strong subcellular polarity during Physcomitrella patens 3D growth.

Defective Kernel 1 (DEK1) is genetically at the nexus of the 3D morphogenesis of land plants. We aimed to localize DEK1 in the moss Physcomitrella patens to decipher its function during this process. To detect DEK1 in vivo, we inserted the tdTomato fluorophore into PpDEK1 gene locus.

Genome mapping of seed-borne allergens and immunoresponsive proteins in wheat.

Wheat is an important staple grain for humankind globally because of its end-use quality and nutritional properties and its adaptability to diverse climates. For a small proportion of the population, specific wheat proteins can trigger adverse immune responses and clinical manifestations such as celiac disease, wheat allergy, baker's asthma, and wheat-dependent exercise-induced anaphylaxis (WDEIA). Establishing the content and distribution of the immunostimulatory regions in wheat has been hampered by the complexity of the wheat genome and the lack of complete genome sequence information.

An intragenic mutagenesis strategy in Physcomitrella patens to preserve intron splicing.

Gene targeting is a powerful reverse genetics technique for site-specific genome modification. Intrinsic homologous recombination in the moss Physcomitrella patens permits highly effective gene targeting, a characteristic that makes this organism a valuable model for functional genetics. Functional characterization of domains located within a multi-domain protein depends on the ability to generate mutants harboring genetic modifications at internal gene positions while maintaining the reading-frames of the flanking exons.

The DEK1 Calpain Linker Functions in Three-Dimensional Body Patterning in Physcomitrella patens.

The DEFECTIVE KERNEL1 (DEK1) calpain is a conserved 240-kD key regulator of three-dimensional body patterning in land plants acting via mitotic cell plane positioning. The activity of the cytosolic C-terminal calpain protease is regulated by the membrane-anchored DEK1 MEM, which is connected to the calpain via the 600-amino acid residue Linker. Similar to the calpain and MEM domains, the Linker is highly conserved in the land plant lineage, the similarity dropping sharply compared with orthologous charophyte sequences.

The phenotype of the CRINKLY4 deletion mutant of Physcomitrella patens suggests a broad role in developmental regulation in early land plants.

Deletion of the ancestral gene of the land plant multigene family of receptor like kinase CR4 in Physcomitrella patens demonstrates involvement in developmental control of gametophytic and sporophytic organs. The CRINKLY4 (CR4) family of receptor kinases in angiosperms consists of three clades, one including CR4, the CR4-related CCR1 and CCR2, a second including CCR3 and CCR4 family members, and a third and more distant clade. In addition to crinkly leaves in maize, which gave rise to the mutant gene name, CR4 is implicated in ovule, embryo, flower and root development in Arabidopsis thaliana.

DEK1; missing piece in puzzle of plant development.

Patterning of land plant bodies is determined by positioning of cell walls. A crucial event in land plant evolution was the ability to utilize spatial information to direct cell wall deposition. Recent studies of DEK1 in Physcomitrella patens support a role for DEK1 in position dependent cell wall orientation.

Genetic analysis of DEFECTIVE KERNEL1 loop function in three-dimensional body patterning in Physcomitrella patens.

DEFECTIVE KERNEL1 (DEK1) of higher plants plays an essential role in position-dependent signaling and consists of a large transmembrane domain (MEM) linked to a protease catalytic domain and a regulatory domain. Here, we show that the postulated sensory Loop of the MEM domain plays an important role in the developmental regulation of DEK1 activity in the moss Physcomitrella patens. Compared with P.

Utilization of deletion bins to anchor and order sequences along the wheat 7B chromosome.

A total of 3,671 sequence contigs and scaffolds were mapped to deletion bins on wheat chromosome 7B providing a foundation for developing high-resolution integrated physical map for this chromosome. Bread wheat (Triticum aestivum L.) has a large, complex and highly repetitive genome which is challenging to assemble into high quality pseudo-chromosomes.

Ancient hybridizations among the ancestral genomes of bread wheat.

The allohexaploid bread wheat genome consists of three closely related subgenomes (A, B, and D), but a clear understanding of their phylogenetic history has been lacking. We used genome assemblies of bread wheat and five diploid relatives to analyze genome-wide samples of gene trees, as well as to estimate evolutionary relatedness and divergence times. We show that the A and B genomes diverged from a common ancestor ~7 million years ago and that these genomes gave rise to the D genome through homoploid hybrid speciation 1 to 2 million years later.

Genome interplay in the grain transcriptome of hexaploid bread wheat.

Allohexaploid bread wheat (Triticum aestivum L.) provides approximately 20% of calories consumed by humans. Lack of genome sequence for the three homeologous and highly similar bread wheat genomes (A, B, and D) has impeded expression analysis of the grain transcriptome.

Defective Kernel 1 (DEK1) is required for three-dimensional growth in Physcomitrella patens.

Orientation of cell division is critical for plant morphogenesis. This is evident in the formation and function of meristems and for morphogenetic transitions. Mosses undergo such transitions: from two-dimensional tip-growing filaments (protonema) to the generation of three-dimensional leaf-like structures (gametophores).

The catalytic domain CysPc of the DEK1 calpain is functionally conserved in land plants.

DEK1, the single calpain of land plants, is a member of the ancient membrane bound TML-CysPc-C2L calpain family that dates back 1.5 billion years. Here we show that the CysPc-C2L domains of land plant calpains form a separate sub-clade in the DEK1 clade of the phylogenetic tree of plants.

Integration of mate pair sequences to improve shotgun assemblies of flow-sorted chromosome arms of hexaploid wheat.

Background: The assembly of the bread wheat genome sequence is challenging due to allohexaploidy and extreme repeat content (>80%). Isolation of single chromosome arms by flow sorting can be used to overcome the polyploidy problem, but the repeat content cause extreme assembly fragmentation even at a single chromosome level. Long jump paired sequencing data (mate pairs) can help reduce assembly fragmentation by joining multiple contigs into single scaffolds.

Massive expansion of the calpain gene family in unicellular eukaryotes.

Background: Calpains are Ca2+-dependent cysteine proteases that participate in a range of crucial cellular processes. Dysfunction of these enzymes may cause, for instance, life-threatening diseases in humans, the loss of sex determination in nematodes and embryo lethality in plants. Although the calpain family is well characterized in animal and plant model organisms, there is a great lack of knowledge about these genes in unicellular eukaryote species (i.

A system for monitoring physical activity data among people with type 2 diabetes.

Trends towards lower levels of physical activity have raised health concerns. Tools to capture, store and use information about physical activity might improve motivation to increase the level of such activity. This is especially important for Type 2 diabetes, since physical activity is one of the key components in achieving healthy blood glucose values.

Subcellular localization and functional domain studies of DEFECTIVE KERNEL1 in maize and Arabidopsis suggest a model for aleurone cell fate specification involving CRINKLY4 and SUPERNUMERARY ALEURONE LAYER1.

DEFECTIVE KERNEL1 (DEK1), which consists of a membrane-spanning region (DEK1-MEM) and a calpain-like Cys proteinase region (DEK1-CALP), is essential for aleurone cell formation at the surface of maize (Zea mays) endosperm. Immunolocalization and FM4-64 dye incubation experiments showed that DEK1 and CRINKLY4 (CR4), a receptor kinase implicated in aleurone cell fate specification, colocalized to plasma membrane and endosomes. SUPERNUMERARY ALEURONE LAYER1 (SAL1), a negative regulator of aleurone cell fate encoding a class E vacuolar sorting protein, colocalized with DEK1 and CR4 in endosomes.

The Arabidopsis thaliana AT PRP39-1 gene, encoding a tetratricopeptide repeat protein with similarity to the yeast pre-mRNA processing protein PRP39, affects flowering time.

Flowering is regulated by a network integrated from four major pathways, including the photoperiod, vernalization, gibberellin, and autonomous pathways. RNA processing within the autonomous pathway is well known to regulate Arabidopsis thaliana flowering time. Here we identify a novel Arabidopsis gene, designated AT PRP39-1, that affects flowering time.

Surface position, not signaling from surrounding maternal tissues, specifies aleurone epidermal cell fate in maize.

Maize (Zea mays) endosperm consists of an epidermal-like surface layer of aleurone cells, an underlying body of starchy endosperm cells, and a basal layer of transfer cells. To determine whether surrounding maternal tissues perform a role in specifying endosperm cell fates, a maize endosperm organ culture technique was established whereby the developing endosperm is completely removed from surrounding maternal tissues. Using cell type-specific fluorescence markers, we show that aleurone cell fate specification occurs exclusively in response to surface position and does not require specific, continued maternal signal input.

Biochemical characterization of a truncated penta-EF-hand Ca2+ binding protein from maize.

Plants possess multiple genes encoding calcium sensor proteins that are members of the penta-EF-hand (PEF) family. Characterized PEF proteins such as ALG-2 (apoptosis-linked gene 2 product) and the calpain small subunit function in diverse cellular processes in a calcium-dependent manner by interacting with their target proteins at either their N-terminal extension or Ca2+ binding domains. We have identified a previously unreported class of PEF proteins in plants that are notable because they do not possess the hydrophobic amino acid rich N-terminal extension that is typical of these PEF proteins.

Mutation in the Arabidopisis thaliana DEK1 calpain gene perturbs endosperm and embryo development while over-expression affects organ development globally.

A T-DNA insertion in the Arabidopsis thaliana DEK1 gene, encoding a calpain-like cysteine proteinase with a predicted membrane anchor, causes unorganized embryo development displaying irregular mitotic divisions in the embryo proper and suspensor. Embryo development is arrested at the globular stage, and the embryo proper lacks a defined protoderm. In the endosperm, the aleurone-like peripheral cell layer is partly or completely lacking.