Structure-function analysis of Arabidopsis TOPLESS reveals fundamental conservation of repression mechanisms across eukaryotes

SummaryThe plant corepressor TOPLESS (TPL) is recruited to a large number of loci that are selectively induced in response to developmental or environmental cues, yet the mechanisms by which it inhibits expression in the absence of these stimuli is poorly understood. Previously, we had used the N-terminus of Arabidopsis thaliana TPL to enable repression of a synthetic auxin response circuit in Saccharomyces cerevisiae (yeast). Here, we leveraged the yeast system to interrogate the relationship between TPL structure and function, specifically scanning for repression domains. We identified a potent repression domain in Helix 8 located within the CRA domain, which directly interacted with the Mediator middle domain subunits Med21 and Med10. Interactions between TPL and Mediator were required to fully repress transcription in both yeast and plants. In contrast, we found that multimer formation, a conserved feature of many corepressors, had minimal influence on the repression strength of TPL.

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Repression by the Arabidopsis TOPLESS corepressor requires association with the core Mediator complex

eLife ◽

10.7554/elife.66739 ◽

2021 ◽

Vol 10 ◽

Author(s):

Alexander R Leydon ◽

Wei Wang ◽

Hardik P Gala ◽

Sabrina Gilmour ◽

Samuel Juarez-Solis ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Structure And Function ◽

Mediator Complex ◽

Environmental Cues ◽

Auxin Response ◽

The Core ◽

N Terminus ◽

And Function ◽

The Relationship ◽

Repression Domain

The plant corepressor TOPLESS (TPL) is recruited to a large number of loci that are selectively induced in response to developmental or environmental cues, yet the mechanisms by which it inhibits expression in the absence of these stimuli is poorly understood. Previously, we had used the N-terminus of Arabidopsis thaliana TPL to enable repression of a synthetic auxin response circuit in Saccharomyces cerevisiae (yeast). Here, we leveraged the yeast system to interrogate the relationship between TPL structure and function, specifically scanning for repression domains. We identified a potent repression domain in Helix 8 located within the CRA domain, which directly interacted with the Mediator middle module subunits Med21 and Med10. Interactions between TPL and Mediator were required to fully repress transcription in both yeast and plants. In contrast, we found that multimer formation, a conserved feature of many corepressors, had minimal influence on the repression strength of TPL.

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Study of the relationship between structure and function of HIV-1 gp 41 N terminus fusion peptide

Chinese Peptide Symposia - Peptides Biology and Chemistry ◽

10.1007/0-306-46880-8_26 ◽

2005 ◽

pp. 104-107 ◽

Cited By ~ 1

Author(s):

Man Wu ◽

Song-Qing Nie ◽

Yang Qiu ◽

Ke-Chun Lin ◽

Shao-Xiong Wang ◽

...

Keyword(s):

Fusion Peptide ◽

Structure And Function ◽

N Terminus ◽

And Function ◽

The Relationship ◽

Hiv 1

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Structure and Function of the Saccharomyces cerevisiae Sir3 BAH Domain

Molecular and Cellular Biology ◽

10.1128/mcb.26.8.3256-3265.2006 ◽

2006 ◽

Vol 26 (8) ◽

pp. 3256-3265 ◽

Cited By ~ 44

Author(s):

Jessica J. Connelly ◽

Peihua Yuan ◽

Hao-Chi Hsu ◽

Zhizhong Li ◽

Rui-Ming Xu ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Protein A ◽

Transcriptional Silencing ◽

Structure And Function ◽

Full Length ◽

Left Handed ◽

N Terminus ◽

Bah Domain ◽

And Function

ABSTRACT Previous work has shown that the N terminus of the Saccharomyces cerevisiae Sir3 protein is crucial for the function of Sir3 in transcriptional silencing. Here, we show that overexpression of N-terminal fragments of Sir3 in strains lacking the full-length protein can lead to some silencing of HML and HMR. Sir3 contains a BAH (bromo-adjacent homology) domain at its N terminus. Overexpression of this domain alone can lead to silencing as long as Sir1 is overexpressed and Sir2 and Sir4 are present. Overexpression of the closely related Orc1 BAH domain can also silence in the absence of any Sir3 protein. A previously characterized hypermorphic sir3 mutation, D205N, greatly improves silencing by the Sir3 BAH domain and allows it to bind to DNA and oligonucleosomes in vitro. A previously uncharacterized region in the Sir1 N terminus is required for silencing by both the Sir3 and Orc1 BAH domains. The structure of the Sir3 BAH domain has been determined. In the crystal, the molecule multimerizes in the form of a left-handed superhelix. This superhelix may be relevant to the function of the BAH domain of Sir3 in silencing.

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The Where, When, and How of Organelle Acidification by the Yeast Vacuolar H+-ATPase

Microbiology and Molecular Biology Reviews ◽

10.1128/mmbr.70.1.177-191.2006 ◽

2006 ◽

Vol 70 (1) ◽

pp. 177-191 ◽

Cited By ~ 286

Author(s):

Patricia M. Kane

Keyword(s):

Saccharomyces Cerevisiae ◽

Current Knowledge ◽

Structure And Function ◽

Regulatory Mechanisms ◽

Eukaryotic Cells ◽

Higher Eukaryotes ◽

Specific Regulation ◽

And Function ◽

Acidic Organelles ◽

The Relationship

SUMMARY All eukaryotic cells contain multiple acidic organelles, and V-ATPases are central players in organelle acidification. Not only is the structure of V-ATPases highly conserved among eukaryotes, but there are also many regulatory mechanisms that are similar between fungi and higher eukaryotes. These mechanisms allow cells both to regulate the pHs of different compartments and to respond to changing extracellular conditions. The Saccharomyces cerevisiae V-ATPase has emerged as an important model for V-ATPase structure and function in all eukaryotic cells. This review discusses current knowledge of the structure, function, and regulation of the V-ATPase in S. cerevisiae and also examines the relationship between biosynthesis and transport of V-ATPase and compartment-specific regulation of acidification.

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Structure and function analysis of a CC-NBS-LRR protein AT1G12290

Biochemical and Biophysical Research Communications ◽

10.1016/j.bbrc.2020.11.111 ◽

2021 ◽

Vol 534 ◽

pp. 206-211

Author(s):

Jianzhong Huang ◽

Xiaoqiu Wu ◽

Kaiting Sun ◽

Zhiyong Gao

Keyword(s):

Function Analysis ◽

Structure And Function ◽

And Function ◽

Lrr Protein

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The Schizosaccharomyces pombe cho1+ Gene Encodes a Phospholipid Methyltransferase

Genetics ◽

10.1093/genetics/150.2.553 ◽

1998 ◽

Vol 150 (2) ◽

pp. 553-562

Author(s):

Margaret I Kanipes ◽

John E Hill ◽

Susan A Henry

Keyword(s):

Saccharomyces Cerevisiae ◽

Sequence Analysis ◽

Schizosaccharomyces Pombe ◽

Gene Disruption ◽

Structure And Function ◽

Biosynthetic Enzyme ◽

Gene Encoding ◽

Complementation Groups ◽

Eukaryotic Organisms ◽

And Function

Abstract The isolation of mutants of Schizosaccharomyces pombe defective in the synthesis of phosphatidylcholine via the methylation of phosphatidylethanolamine is reported. These mutants are choline auxotrophs and fall into two unlinked complementation groups, cho1 and cho2. We also report the analysis of the cho1+ gene, the first structural gene encoding a phospholipid biosynthetic enzyme from S. pombe to be cloned and characterized. The cho1+ gene disruption mutant (cho1Δ) is viable if choline is supplied and resembles the cho1 mutants isolated after mutagenesis. Sequence analysis of the cho1+ gene indicates that it encodes a protein closely related to phospholipid methyltransferases from Saccharomyces cerevisiae and rat. Phospholipid methyltransferases encoded by a rat liver cDNA and the S. cerevisiae OPI3 gene are both able to complement the choline auxotrophy of the S. pombe cho1 mutants. These results suggest that both the structure and function of the phospholipid N-methyltransferases are broadly conserved among eukaryotic organisms.

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Lung ultrasound presentation of COVID-19 patients: phenotypes and correlations

Internal and Emergency Medicine ◽

10.1007/s11739-020-02620-9 ◽

2021 ◽

Author(s):

Gianmarco Secco ◽

◽

Marzia Delorenzo ◽

Francesco Salinaro ◽

Caterina Zattera ◽

...

Keyword(s):

Intensive Care Unit ◽

Intensive Care ◽

Lung Ultrasound ◽

Structure And Function ◽

General Ward ◽

Prognostic Role ◽

Interstitial Syndrome ◽

Lung Structure ◽

And Function ◽

The Relationship

AbstractBedside lung ultrasound (LUS) can play a role in the setting of the SarsCoV2 pneumonia pandemic. To evaluate the clinical and LUS features of COVID-19 in the ED and their potential prognostic role, a cohort of laboratory-confirmed COVID-19 patients underwent LUS upon admission in the ED. LUS score was derived from 12 fields. A prevalent LUS pattern was assigned depending on the presence of interstitial syndrome only (Interstitial Pattern), or evidence of subpleural consolidations in at least two fields (Consolidation Pattern). The endpoint was 30-day mortality. The relationship between hemogasanalysis parameters and LUS score was also evaluated. Out of 312 patients, only 36 (11.5%) did not present lung involvment, as defined by LUS score < 1. The majority of patients were admitted either in a general ward (53.8%) or in intensive care unit (9.6%), whereas 106 patients (33.9%) were discharged from the ED. In-hospital mortality was 25.3%, and 30-day survival was 67.6%. A LUS score > 13 had a 77.2% sensitivity and a 71.5% specificity (AUC 0.814; p < 0.001) in predicting mortality. LUS alterations were more frequent (64%) in the posterior lower fields. LUS score was related with P/F (R2 0.68; p < 0.0001) and P/F at FiO2 = 21% (R2 0.59; p < 0.0001). The correlation between LUS score and P/F was not influenced by the prevalent ultrasound pattern. LUS represents an effective tool in both defining diagnosis and stratifying prognosis of COVID-19 pneumonia. The correlation between LUS and hemogasanalysis parameters underscores its role in evaluating lung structure and function.

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