Abstract
The diversification of effector function, driven by a co-evolutionary arms race, enables pathogens to establish compatible interactions with hosts. Structurally conserved plant ...pathogenesis-related PR-1 and PR-1-like (PR-1L) proteins are involved in plant defense and fungal virulence, respectively. It is unclear how fungal PR-1L counters plant defense. Here, we show that
Ustilago maydis
UmPR-1La and yeast ScPRY1, with conserved phenolic resistance functions, are Ser/Thr-rich region mediated cell-surface localization proteins. However, UmPR-1La has gained specialized activity in sensing phenolics and eliciting hyphal-like formation to guide fungal growth in plants. Additionally,
U. maydis
hijacks maize cathepsin B-like 3 (CatB3) to release functional CAPE-like peptides by cleaving UmPR-1La’s conserved CNYD motif, subverting plant CAPE-primed immunity and promoting fungal virulence. Surprisingly, CatB3 avoids cleavage of plant PR-1s, despite the presence of the same conserved CNYD motif. Our work highlights that UmPR-1La has acquired additional dual roles to suppress plant defense and sustain the infection process of fungal pathogens.
Abstract
The recent discovery of SPINDLY (SPY)-catalyzed protein O-fucosylation revealed a novel mechanism for regulating nucleocytoplasmic protein functions in plants. Genetic evidence indicates the ...important roles of SPY in diverse developmental and physiological processes. However, the upstream signal controlling SPY activity and the downstream substrate proteins O-fucosylated by SPY remain largely unknown. Here, we demonstrated that SPY mediates sugar-dependent growth in Arabidopsis (Arabidopsis thaliana). We further identified hundreds of O-fucosylated proteins using lectin affinity chromatography followed by mass spectrometry. All the O-fucosylation events quantified in our proteomic analyses were undetectable or dramatically decreased in the spy mutants, and thus likely catalyzed by SPY. The O-fucosylome includes mostly nuclear and cytosolic proteins. Many O-fucosylated proteins function in essential cellular processes, phytohormone signaling, and developmental programs, consistent with the genetic functions of SPY. The O-fucosylome also includes many proteins modified by O-linked N-acetylglucosamine (O-GlcNAc) and by phosphorylation downstream of the target of rapamycin (TOR) kinase, revealing the convergence of these nutrient signaling pathways on key regulatory functions such as post-transcriptional/translational regulation and phytohormone responses. Our study identified numerous targets of SPY/O-fucosylation and potential nodes of crosstalk among sugar/nutrient signaling pathways, enabling future dissection of the signaling network that mediates sugar regulation of plant growth and development.
A proteomic profiling of O-fucose-modified intracellular proteins in Arabidopsis reveals mechanisms of sugar-dependent growth regulation and crosstalk among nutrient-sensing pathways.
Transposons are generally kept silent by epigenetic mechanisms including DNA methylation. Here, we identified a pair of Harbinger transposon-derived Rroteins （HDPs）, HDP1 and HDP2, as anti-silencing ...factors in Arabidopsis. hdp1 and hdp2 mutants displayed an enhanced silencing of transgenes and some transposons. Phylogenetic analyses revealed that HDP1 and HDP2 were co-domesticated from the Harbinger transposon-encoded transposase and DNA-binding protein, respectively. HDP1 interacts with HDP2 in the nucleus, analogous to their transposon counterparts. Moreover, HDP1 and HDP2 are associated with IDMI, IDM2, IDM3 and MBD7 that constitute a histone acetyltransferase complex functioning in DNA demethylation. HDP2 and the methyl-DNA-binding protein MBD7 share a large set of common genomic binding sites, indicating that they jointly determine the target specificity of the histone acetyltransferase complex. Thus, our data revealed that HDP1 and HDP2 constitute a functional module that has been recruited to a histone acetyltransferase complex to prevent DNA hypermethylation and epigenetic silencing.
•Serotonergic antidepressants improved overall NPS, agitation, depressive symptom, cognition, and care burden.•Both SSRIs and non-SSRIs significantly reduced agitation and depressive symptoms.•SSRIs, ...but not SSRIs reduced overall NPS and care burden.•Serotonergic antidepressants improved overall NPS among patients with not pure AD compared those with pure AD.
Serotonergic dysfunction may be involved in the etiology of overall neuropsychiatric symptoms (NPS) and agitation in patients with dementia; therefore, we aim to perform a systematic review and meta-analysis to investigate the efficacy of serotonergic antidepressants in such populations.
We systematically searched PubMed, Medline, Embase, and Cochrane Library to obtain randomized controlled trials (RCTs) from the date of their inception until December 11, 2020 to examine the effect of serotonergic antidepressants on the outcomes of interest in patients with dementia. Data were pooled using a random-effects model. Co-primary outcomes were mean changes in overall NPS and agitation as a specific symptom of NPS. Secondary outcomes were mean changes in depressive symptoms, cognition, and care burden.
Fourteen randomized controlled trials were eligible (n = 1,374; mean age = 76.8 years; mean proportion of female = 61.9 %). Serotonergic antidepressants significantly reduced the overall NPS (k = 12, n = 1276, Hedges’ g = −0.49, 95 % confidence intervals CIs = -0.74 to -0.24, p < 0.001) and agitation severity (k = 9, n = 749, Hedges’ g = −0.28, 95 % CIs = −0.43 to −0.14, p < 0.001), both with small effect size in patients with dementia. For secondary outcome, serotonergic antidepressants also significantly improved depressive symptoms, cognition, and care burden with small to very small effect sizes (depressive symptoms, k = 8, n = 938, Hedges’ g = −0.32, 95 % CIs = −0.49 to −0.15, p < 0.001;cognition, k = 6, n = 983, Hedges’ g = 0.15, 95 % CIs = 0.002 to 0.29, p = 0.046; care burden, k = 7, n = 961, Hedges’ g = −0.24, 95 % CIs = −0.41 to −0.07, p = 0.005). Subgroup analysis showed that both selective serotonin reuptake inhibitors (SSRIs) and non-SSRIs significant reduced agitation and depressive symptoms (For agitation, SSRIs, k = 6, n = 605, Hedges’ g = −0.25, 95 % CIs = −0.41 to −0.09, p=0.002; non-SSRIs, k = 3, n = 144, Hedges’ g = −0.41, 95 % CIs = −0.74 to −0.08, p = 0.016; For depression, SSRIs, k = 6, n = 736, Hedges’ g = −0.29, 95 % CIs = −0.48 to −0.09, p=0.004; non-SSRIs, k = 343, n = 144, Hedges’ g = −0.43, 95 % CIs = −0.78 to −0.09, p = 0.016), whereas only SSRIs reduced overall NPS (k = 9, n = 1109, Hedges’ g = −0.49, 95 % CIs = −0.78 to −0.20, p = 0.001) and care burden (k = 5, n = 740, Hedges’ g = −0.29, 95 % CIs = −0.50 to −0.08, p=0.007).
The present meta-analysis indicates that serotonergic antidepressants effectively alleviate overall NPS, agitation, depressive symptoms, and care burden, and improve cognitive function.
Phosphorylation has an incredible impact on the biological behavior of proteins, altering everything from intrinsic activity to cellular localization and complex formation. It is no surprise then ...that this post-translational modification has been the subject of intense study and that, with the advent of faster, more accurate instrumentation, the number of large-scale mass spectrometry-based phosphoproteomic studies has swelled over the past decade. Recent developments in sample preparation, phosphorylation enrichment, quantification, and data analysis strategies permit both targeted and ultra-deep phosphoproteome profiling, but challenges remain in pinpointing biologically relevant phosphorylation events. We describe here technological advances that have facilitated phosphoproteomic analysis of cells, tissues, and biofluids and note applications to neuropathologies in which the phosphorylation machinery may be dysregulated, much as it is in cancer.
Recent advances in phosphoproteomic strategies have made it possible to characterize protein phosphorylation with new depth and coverage, lending key insights into many human diseases.
Protein phosphatases play an essential role in normal cell physiology and the development of diseases such as cancer. The innate challenges associated with studying protein phosphatases have limited ...our understanding of their substrates, molecular mechanisms, and unique functions within highly coordinated networks. Here, we introduce a novel strategy using substrate-trapping mutants coupled with quantitative proteomics methods to identify physiological substrates of Src homology 2 containing protein tyrosine phosphatase 2 (SHP2) in a high-throughput manner. The technique integrates three parallel mass spectrometry-based proteomics experiments, including affinity isolation of substrate-trapping mutant complex using wild-type and SHP2 KO cells, in vivo global quantitative phosphoproteomics, and in vitro phosphatase reaction. We confidently identified 18 direct substrates of SHP2 in the epidermal growth factor receptor signaling pathways, including both known and novel SHP2 substrates. Docking protein 1 was further validated using biochemical assays as a novel SHP2 substrate, providing a mechanism for SHP2-mediated Ras activation. This advanced workflow improves the systemic identification of direct substrates of protein phosphatases, facilitating our understanding of the equally important roles of protein phosphatases in cellular signaling.
Cranial electrotherapy stimulation (CES) is beneficial in reducing anxiety in psychiatric patients. However, no studies have reported on elderly patients with generalized anxiety disorders (GAD). ...This study aimed to determine the efficacy and safety of a 6-week CES intervention for late-life GAD.
This single-arm pilot study assessed 6-week CES treatment (Alpha-Stim AID) for late-life GAD and 4-week follow-up post intervention. The Hamilton Rating Scale for Anxiety (HAMA) and Beck Anxiety Inventory (BAI) were used as baseline and outcome measures at weeks 4, 6, and 10, respectively. Treatment response was defined as 50 % or more reduction of the HAMA score and remission was defined as a of score ≤7 on the HAMA. Other measures included depression, sleep quality, and quality of life assessment.
We included participants (n = 27) aged 68.0 ± 5.0 years, 81.5 % of whom were female. Fifteen (55.6 %), 18 (66.7 %), and 15 (55.6 %) patients were concurrently treated with antidepressants, BZDs, and antipsychotics, respectively. Intention-to-treat (ITT) analysis revealed a significant decrease in HAMA scores from baseline (20.96 ± 3.30) to week 6 (12.26 ± 7.09) and one-month (12.85 ± 7.08) follow-up at W10 (all p < 0.001). The response and remission rates were 33.3 %, 40.7 %, and 48.1 % and 25.9 %, 29.6 %, and 25.9 % at W4, W6, and W10, respectively. The CES improved depression and sleep conditions as measured by the Beck Depression Inventory-II and Pittsburgh Sleep Quality Index.
CES clinically reduces symptoms of anxiety and depression and may improve sleep quality in late-life GAD. Future randomized controlled study is needed.
Methodologies to enrich heterogeneous types of phosphopeptides are critical for comprehensive mapping of the under-explored phosphoproteome. Taking advantage of the distinct binding affinities of ...Ga3+ and Fe3+ for phosphopeptides, we designed a metal-directed immobilized metal ion affinity chromatography for the sequential enrichment of phosphopeptides. In Raji B cells, the sequential Ga3+-Fe3+-immobilized metal affinity chromatography (IMAC) strategy displayed a 1.5–3.5-fold superior phosphoproteomic coverage compared to single IMAC (Fe3+, Ti4+, Ga3+, and Al3+). In addition, up to 92% of the 6283 phosphopeptides were uniquely enriched in either the first Ga3+-IMAC (41%) or second Fe3+-IMAC (51%). The complementary properties of Ga3+ and Fe3+ were further demonstrated through the exclusive enrichment of almost all of 1214 multiply phosphorylated peptides (99.4%) in the Ga3+-IMAC, whereas only 10% of 5069 monophosphorylated phosphopeptides were commonly enriched in both fractions. The application of sequential Ga3+-Fe3+-IMAC to human lung cancer tissue allowed the identification of 2560 unique phosphopeptides with only 8% overlap. In addition to the above-mentioned mono- and multiply phosphorylated peptides, this fractionation ability was also demonstrated on the basic and acidic phosphopeptides: acidophilic phosphorylation sites were predominately enriched in the first Ga3+-IMAC (72%), while Pro-directed (85%) and basophilic (79%) phosphorylation sites were enriched in the second Fe3+-IMAC. This strategy provided complementary mapping of different kinase substrates in multiple cellular pathways related to cancer invasion and metastasis of lung cancer. Given the fractionation ability and ease of tip preparation of this Ga3+-Fe3+-IMAC, we propose that this strategy allows more comprehensive characterization of the phosphoproteome both in vitro and in vivo.
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