22 research outputs found
Association of Arabidopsis type‐II ROPs with the plasma membrane requires a conserved C‐terminal sequence motif and a proximal polybasic domain
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Physcomitrella patens Auxin-Resistant Mutants Affect Conserved Elements of an Auxin-Signaling Pathway
No full textSummaryAuxin regulates most aspects of flowering-plant growth and development, including key developmental innovations that evolved within the vascular plant lineage after diverging from a bryophyte-like ancestor nearly 500 million years ago [1–3]. Recent studies in Arabidopsis indicate that auxin acts by directly binding the TIR1 subunit of the SCFTIR1 ubiquitin ligase; this binding results in degradation of the Aux/IAA transcriptional repressors and de-repression of auxin-responsive genes [4–9]. Little is known, however, about the mechanism of auxin action in other plants. To characterize auxin signaling in a nonflowering plant, we utilized the genetically tractable moss Physcomitrella patens. We used a candidate-gene approach to show that previously identified auxin-resistant mutants of P. patens harbor mutations in Aux/IAA genes. Furthermore, we show that the moss Aux/IAA proteins interact with Arabidopsis TIR1 moss homologs called PpAFB and that a reduction in PpAFB levels results in a phenotype similar to that of the auxin-resistant mutants. Our results indicate that the molecular mechanism of auxin perception is conserved in land plants despite vast differences in the role auxin plays in different plant lineages
DNA Glycosylases Involved in Base Excision Repair May Be Associated with Cancer Risk in BRCA1 and BRCA2 Mutation Carriers.
No full textSingle Nucleotide Polymorphisms (SNPs) in genes involved in the DNA Base Excision Repair (BER) pathway could be
associated with cancer risk in carriers of mutations in the high-penetrance susceptibility genes BRCA1 and BRCA2, given the relation of synthetic lethality that exists between one of the components of the BER pathway, PARP1 (poly ADP ribose
polymerase), and both BRCA1 and BRCA2. In the present study, we have performed a comprehensive analysis of 18 genes involved in BER using a tagging SNP approach in a large series of BRCA1 and BRCA2 mutation carriers. 144 SNPs were analyzed in a two stage study involving 23,463 carriers from the CIMBA consortium (the Consortium of Investigators of Modifiers of BRCA1 and BRCA2). Eleven SNPs showed evidence of association with breast and/or ovarian cancer at p,0.05 in the combined analysis. Four of the five genes for which strongest evidence of association was observed were DNA glycosylases. The strongest evidence was for rs1466785 in the NEIL2 (endonuclease VIII-like 2) gene (HR: 1.09, 95% CI (1.03– 1.16), p = 2.761023) for association with breast cancer risk in BRCA2 mutation carriers, and rs2304277 in the OGG1 (8-guanine DNA glycosylase) gene, with ovarian cancer risk in BRCA1 mutation carriers (HR: 1.12 95%CI: 1.03–1.21,
p = 4.861023). DNA glycosylases involved in the first steps of the BER pathway may be associated with cancer risk in BRCA1/ 2 mutation carriers and should be more comprehensively studied
The impact of an educational intervention on attitudes and beliefs of law students about "what works" in juvenile rehabilitation
No full textElectronic Thesis or DissertationOpinions about "what works" in juvenile justice are often based on poorly informed beliefs and attitudes rather than on scientific evidence. Disseminating credible information remains a challenge. Studies have identified programs that effectively address juvenile offenders while exposing "get tough" alternatives as ineffective. It is important to communicate these findings to future legal policy professionals, many of whom will come from the ranks of today's law students. Previous findings by this author suggest that belief barriers may impact openness to empirical evidence. The current study addressed two questions: Can brief, on-line educational modules change participant knowledge and beliefs about "what works"? How will attitudes influence receptivity to new information? The 161 nationally recruited law students who completed this study were randomly assigned to one of two experimental groups (Module One: "benefits of empirically-supported programs [ESP]" or Module Two: "weaknesses of unsupported programs") or a control group (Module Three: general information about juvenile crime). Prior to receiving an educational module, participants completed surveys regarding demographics, baseline justice related attitudes, and beliefs about program effectiveness. After completing the modules, participants rated program effectiveness again. Results at pre-test demonstrated that individuals were readily categorized as having either a treatment-focused "supportive" belief system or a punitive "get tough" belief system. The "supportive" group tended to rate ESP as highly effective while the "get tough" participants tended to rate unsupported programs as highly effective, while also emphasizing the lack of effectiveness for ESP. Although baseline attitudes were significant predictors of pre-test program ratings, at post-test, it was clear that exposure to Module One not only produced the expected result (i.e., raising the ESP effectiveness ratings), but also had a notable carryover and corrective influence on subsequent ratings of unsupported programs. Module Two also produced expected results (i.e., lowering the post-test ratings of unsupported program effectiveness). Following exposure to educational modules based on empirical evidence, it appeared that pre-existing attitudes no longer played a significant role in assigning program effectiveness ratings. Module One had a particularly robust effect on post-test ratings; these were in line with the research literature on "what works" in juvenile intervention
A Novel ROP/RAC Effector Links Cell Polarity, Root-Meristem Maintenance, and Vesicle Trafficking
No full textSummaryROP/RAC GTPases are master regulators of cell polarity in plants, implicated in the regulation of diverse signaling cascades including cytoskeleton organization, vesicle trafficking, and Ca2+ gradients [1–8]. The involvement of ROPs in differentiation processes is yet unknown. Here we show the identification of a novel ROP/RAC effector, designated interactor of constitutive active ROPs 1 (ICR1), that interacts with GTP-bound ROPs. ICR1 knockdown or silencing leads to cell deformation and loss of root stem-cell population. Ectopic expression of ICR1 phenocopies activated ROPs, inducing cell deformation of leaf-epidermis-pavement and root-hair cells [3, 5, 6, 9]. ICR1 is comprised of coiled-coil domains and forms complexes with itself and the exocyst vesicle-tethering complex subunit SEC3 [10–13]. The ICR1-SEC3 complexes can interact with ROPs in vivo. Plants overexpressing a ROP- and SEC3-noninteracting ICR1 mutant have a wild-type phenotype. Taken together, our results show that ICR1 is a scaffold-mediating formation of protein complexes that are required for cell polarity, linking ROP/RAC GTPases with vesicle trafficking and differentiation
Correction: Corrigendum: N-acetyl ornithine deacetylase is a moonlighting protein and is involved in the adaptation of Entamoeba histolytica to nitrosative stress
No full textScientific Reports 6: Article number: 36323; published online: 03 November 2016; updated: 05 April 2017 The original version of this Article contained errors in the spelling of the author Sharon Baumel-Alterzon, which was incorrectly given as Sharon Alterzon-Baumel. These errors have now been corrected in the PDF and HTML versions of the Article.</jats:p
Comparative mutant analyses reveal a novel mechanism of ARF regulation in land plants
No full textAdditional data associated with the publication "Comparative mutant analyses reveal a novel mechanism of ARF regulation in land plants" Nature Plants, 2025. Abstract: The plant hormone auxin regulates a wide variety of transcriptional responses depending on the cell type, environment, and species. How this diversity is achieved may be related to the specific complement of auxin signalling components in each cell. The levels of activators (class-A AUXIN RESPONSE FACTORS) and repressors (class-B ARFs) are particularly important. Tight regulation of ARF protein levels is likely key in determining this balance. Through comparative analysis of novel, dominant mutants in maize and the moss Physcomitrium patens, we have discovered a ~500-million-year-old mechanism of class-B ARF protein level regulation mediated by proteasome degradation, important in determining cell fate decisions across land plants. Thus, our results add a key piece to the puzzle of how auxin regulates plant development. These datasets are in addition to those included in the supplmentary materials in the paper, the raw sequence data provided in the NCBI GEO deposit, and the github pages (https://github.com/ThePlantShapeLab/Truffula ) ## The raw sequence data associated with the project is available to download at GEO accession numbers GSE293375, GSE293431, GSE29343
Comparative mutant analyses reveal a novel mechanism of ARF regulation in land plants
No full textAdditional data associated with the publication "Comparative mutant analyses reveal a novel mechanism of ARF regulation in land plants" Nature Plants, 2025.
Abstract:
The plant hormone auxin regulates a wide variety of transcriptional responses depending on the cell type, environment, and species. How this diversity is achieved may be related to the specific complement of auxin signalling components in each cell. The levels of activators (class-A AUXIN RESPONSE FACTORS) and repressors (class-B ARFs) are particularly important. Tight regulation of ARF protein levels is likely key in determining this balance. Through comparative analysis of novel, dominant mutants in maize and the moss Physcomitrium patens, we have discovered a ~500-million-year-old mechanism of class-B ARF protein level regulation mediated by proteasome degradation, important in determining cell fate decisions across land plants. Thus, our results add a key piece to the puzzle of how auxin regulates plant development.
These datasets are in addition to those included in the supplmentary materials in the paper, the raw sequence data provided in the NCBI GEO deposit, and the github pages (https://github.com/ThePlantShapeLab/Truffula )
##
The raw sequence data associated with the project is available to download at GEO accession numbers GSE293375, GSE293431, GSE293432Please see README_Comparative mutant analyses reveal a novel mechanism of ARF regulation in land plants.txt file for information on each datase
