Guygraversen0134

Calcium (Ca2+)-dependent protein kinases (CDPKs or CPKs) are a unique family of Ca2+ sensor/kinase-effector proteins with diverse functions in plants. In Arabidopsis thaliana, CPK28 contributes to immune homeostasis by promoting degradation of the key immune signaling receptor-like cytoplasmic kinase BOTRYTIS-INDUCED KINASE 1 (BIK1) and additionally functions in vegetative-to-reproductive stage transition. How CPK28 controls these seemingly disparate pathways is unknown. Here, we identify a single phosphorylation site in the kinase domain of CPK28 (Ser318) that is differentially required for its function in immune homeostasis and stem elongation. We show that CPK28 undergoes intermolecular autophosphorylation on Ser318 and can additionally be transphosphorylated on this residue by BIK1. Analysis of several other phosphorylation sites demonstrates that Ser318 phosphorylation is uniquely required to prime CPK28 for Ca2+ activation at physiological concentrations of Ca2+, possibly through stabilization of the Ca2+-bound active state as indicated by intrinsic fluorescence experiments. Together, our data indicate that phosphorylation of Ser318 is required for the activation of CPK28 at low intracellular [Ca2+] to prevent initiation of an immune response in the absence of infection. By comparison, phosphorylation of Ser318 is not required for stem elongation, indicating pathway-specific requirements for phosphorylation-based Ca2+-sensitivity priming. We additionally provide evidence for a conserved function for Ser318 phosphorylation in related group IV CDPKs, which holds promise for biotechnological applications by generating CDPK alleles that enhance resistance to microbial pathogens without consequences to yield.Galectin-3 (Gal3) exhibits dynamic oligomerization and promiscuous binding, which can lead to concomitant activation of synergistic, antagonistic, or noncooperative signaling pathways that alter cell behavior. Conferring signaling pathway selectivity through mutations in the Gal3-glycan binding interface is challenged by the abundance of common carbohydrate types found on many membrane glycoproteins. Here, employing alpha-helical coiled-coils as scaffolds to create synthetic Gal3 constructs with defined valency, we demonstrate that oligomerization can physically regulate extracellular signaling activity of Gal3. Constructs with 2 to 6 Gal3 subunits ("Dimer," "Trimer," "Tetramer," "Pentamer," "Hexamer") demonstrated glycan-binding properties and cell death-inducing potency that scaled with valency. Dimer was the minimum functional valency. Unlike wild-type Gal3, which signals apoptosis and mediates agglutination, synthetic Gal3 constructs induced cell death without agglutination. In the presence of CD45, Hexamer was distributed on the cell membrane, whereas it clustered in absence of CD45 via membrane glycans other than those found on CD7. Wild-type Gal3, Pentamer, and Hexamer required CD45 and CD7 to signal apoptosis, and the involvement of caspases in apoptogenic signaling was increased in absence of CD45. However, wild-type Gal3 depended on caspases to signal apoptosis to a greater extent than Hexamer, which had greater caspase dependence than Pentamer. Diminished caspase activation downstream of Hexamer signaling led to decreased pannexin-1 hemichannel opening and interleukin-2 secretion, events facilitated by the increased caspase activation downstream of wild-type Gal3 signaling. selleck inhibitor Thus, synthetic fixation of Gal3 multivalency can impart physical control of its outside-in signaling activity by governing membrane glycoprotein engagement and, in turn, intracellular pathway activation.Chemical insecticides remain the main strategy to combat mosquito-borne diseases, but the growing threat of insecticide resistance prompts the urgent need to develop alternative, ecofriendly, and sustainable vector control tools. Entomopathogenic fungi can overcome insecticide resistance and represent promising biocontrol tools for the control of mosquitoes. However, insects have evolved robust defense mechanisms against infection. Better understanding of mosquito defenses against fungal infection is critical for improvement of fungal efficacy. Here, we show that as the pathogenic fungus Beauveria bassiana penetrates into the host hemocoel, mosquitoes increase expression of the let-7 and miR-100 microRNAs (miRNAs). Both miRNAs translocate into fungal hyphae to specifically silence the virulence-related genes sec2p and C6TF, encoding a Rab guanine nucleotide exchange factor and a Zn(II)2Cys6 transcription factor, respectively. Inversely, expression of a let-7 sponge (anti-let-7) or a miR-100 sponge (anti-miR-100) in the fungus efficiently sequesters the corresponding translocated host miRNA. Notably, B. bassiana strains expressing anti-let-7 and anti-miR-100 are markedly more virulent to mosquitoes. Our findings reveal an insect defense strategy that employs miRNAs to induce cross-kingdom silencing of pathogen virulence-related genes, conferring resistance to infection.Corals from the northern Red Sea and Gulf of Aqaba exhibit extreme thermal tolerance. To examine the underlying gene expression dynamics, we exposed Stylophora pistillata from the Gulf of Aqaba to short-term (hours) and long-term (weeks) heat stress with peak seawater temperatures ranging from their maximum monthly mean of 27 °C (baseline) to 29.5 °C, 32 °C, and 34.5 °C. Corals were sampled at the end of the heat stress as well as after a recovery period at baseline temperature. Changes in coral host and symbiotic algal gene expression were determined via RNA-sequencing (RNA-Seq). Shifts in coral microbiome composition were detected by complementary DNA (cDNA)-based 16S ribosomal RNA (rRNA) gene sequencing. In all experiments up to 32 °C, RNA-Seq revealed fast and pervasive changes in gene expression, primarily in the coral host, followed by a return to baseline gene expression for the majority of coral (>94%) and algal (>71%) genes during recovery. At 34.5 °C, large differences in gene expression were observed with minimal recovery, high coral mortality, and a microbiome dominated by opportunistic bacteria (including Vibrio species), indicating that a lethal temperature threshold had been crossed. Our results show that the S. pistillata holobiont can mount a rapid and pervasive gene expression response contingent on the amplitude and duration of the thermal stress. We propose that the transcriptomic resilience and transcriptomic acclimation observed are key to the extraordinary thermal tolerance of this holobiont and, by inference, of other northern Red Sea coral holobionts, up to seawater temperatures of at least 32 °C, that is, 5 °C above their current maximum monthly mean.