translation elongation
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Plant Disease ◽  
2022 ◽  
Liu Yang ◽  
Tian Yuan ◽  
Xia Zhao ◽  
Yue Liang ◽  

Root rot is a serious disease in plantations of A. sinensis, severely affecting yield and quality and threatening sustainable production. Fusarium isolates (n=32) were obtained from field samples of root rot tissue, leaves and infected soil. Isolates were identified by comparing the sequences of their internal transcribed spacer (ITS) region and translation elongation factor 1-ɑ (TEF-1ɑ) to sequences of known species in the NCBI-database. These Fusarium isolates include F. tricinctum (43.75%), F. equiseti (31.25%), F. solani (9.37%), F. oxysporum (6.25%), F. acuminatum (6.25%), and F. incarnatum (3.12%). For pathogenicity testing under greenhouse conditions, seven isolates were selected based on a phylogenetic analysis, including four strains of F. tricinctum and one strain each of F. solani, F. oxysporum, and F. acuminatum. The seven isolates were all pathogenic but differed in their ability to infect: the four F. tricinctum strains were capable pathogens causing root rot in A. sinensis at 100% incidence and the highly aggressive. Furthermore, the symptoms of root rot induced by those seven isolates were consistent with typical root rot cases in the field, but their disease severity varied. Observed histopathological preparations of F. tricinctum-infected seedlings and tissue-slides results showed this fungal species can penetrate epidermal cells and colonize the cortical cells where it induces necrosis and severe plasmolysis. Plate confrontation experiments showed that isolated rhizosphere bacteria inhibited the Fusarium pathogens that cause root rot in A. sinensis. Our results provide timely information for informing the use of biocontrol agents for suppression of root rot disease.

2022 ◽  
Vol 8 (1) ◽  
pp. 70
Vanice Rodrigues Poester ◽  
Rossana Patricia Basso ◽  
David A. Stevens ◽  
Lívia Silveira Munhoz ◽  
Vanessa Brito de Souza Rabello ◽  

We describe the successful treatment of a series of 30 zoonotic sporotrichosis cases from southern Brazil. Sporothrix brasiliensis was the species genotypically identified in all 25 confirmed cases. Five other cases were classified as probable, without laboratory confirmation, but with clinical and epidemiological data of cat-transmitted sporotrichosis. Two isolates were sequenced by translation elongation factor-1 alpha (EF1α) loci in order to compare their sequences, and both of them showed distinct genotypes from S. brasiliensis strains from other Brazilian states. Itraconazole (ITZ) or potassium iodide (KI) were the first choice treatment in 28 and 2 cases, respectively. Microdilution assay showed a wild-type profile of S. brasiliensis isolates to ITZ. However, a lack of clinical response occurred in 42% of cases, especially those treated with ITZ 100 mg/day, and treatment needed modifications, by either increased doses or antifungal combinations. Clinical cure required a mean of 187 days of treatment, which was dependent on the clinical form of the disease and age of patients. Therapy, including dosages and durations, for cutaneous forms of sporotrichosis requires re-evaluation, since cases caused by S. brasiliensis may influence treatment efficacy.

Phytotaxa ◽  
2022 ◽  
Vol 530 (2) ◽  
pp. 177-188

Types and recently collected samples of two Paxillus species namely P. rhytidophyllus and P. yunnanensis, originally described from southwestern China, were critically restudied based on morphology and molecular phylogenetic data of DNA sequences from the large subunit of the nuclear ribosomal RNA (nrLSU), the nuclear ribosomal internal transcribed spacer (ITS), and the translation elongation factor 1-α (tef1-α). The results showed that these two species belong to Boletinellus and Tricholomopsis, respectively. Thus, two new combinations, Boletinellus rhytidophyllus and Tricholomopsis yunnanensis are proposed. Boletinellus rhytidophyllus is characterized by a deeply decurrent and shallow hymenophore which is poroid-lamellate to alveolate, slightly thick-walled (0.6–1 μm) basidiospores, occasionally 2- to 4-spored basidia, rare or infrequent hymenial cystidia, and a trichodermal pileipellis. Tricholomopsis yunnanensis is characterized by a convex pileus densely covered by red-violet to red-brown fibrillose squamules, a yellowish stipe sparsely covered with red to red-brown fibrillose squamules, subglobose to broadly ellipsoid basidiospores, prominent large cheilocystidia measuring 60–195 × 11–39 μm, and a palisadic pileipellis. New descriptions and line drawings of these two species and their comparisons with allied taxa are presented.

2022 ◽  
MaKenzie R. Scarpitti ◽  
Julia E. Warrick ◽  
Michael G. Kearse

Loss of functional fragile X mental retardation protein (FMRP) causes fragile X syndrome, the leading form of inherited intellectual disability and the most common monogenic cause of autism spectrum disorders. FMRP is an RNA-binding protein that controls neuronal mRNA localization and translation. Notably, FMRP is thought to inhibit translation elongation after being recruited to target transcripts via binding RNA G-quadruplexes (G4s) within the coding sequence. Here we directly tested this model and report that FMRP inhibits translation elongation independent of mRNA G4s. Furthermore, we found that the RGG box motif together with its natural C-terminal domain forms a non-canonical RNA-binding domain (ncRBD) that binds reporter mRNA and all four polymeric RNA sequences. The ncRBD is essential for FMRP to inhibit translation. Transcripts that are bound by FMRP through the ncRBD co-sediment with heavy polysomes, which is consistent with stalling elongating ribosomes and a subsequent accumulation of slowed polysomes. Together, this work shifts our understanding of how FMRP inhibits translation elongation and supports a model where repression is driven by local FMRP and mRNA concentrations rather than target mRNA sequence.

2022 ◽  
Vol 8 ◽  
Jamie O. Yang ◽  
Hapet Shaybekyan ◽  
Yan Zhao ◽  
Xuedong Kang ◽  
Gregory A. Fishbein ◽  

We report a case of hypertrophic cardiomyopathy and lactic acidosis in a 3-year-old female. Cardiac and skeletal muscles biopsies exhibited mitochondrial hyperplasia with decreased complex IV activity. Whole exome sequencing identified compound heterozygous variants, p.Arg333Trp and p.Val119Leu, in TSFM, a nuclear gene that encodes a mitochondrial translation elongation factor, resulting in impaired oxidative phosphorylation and juvenile hypertrophic cardiomyopathy.

2021 ◽  
Minji Kim ◽  
Lukasz Samluk ◽  
Tomasz Maciej Stępkowski ◽  
Ida Suppanz ◽  
Remigiusz Adam Serwa ◽  

Perturbed proteostasis and mitochondrial dysfunction are often associated with age-related diseases such as Alzheimer′s and Parkinson′s diseases. However, the link between them remains incompletely understood. Mitochondrial dysfunction causes proteostasis imbalance, and cells respond to restore proteostasis by increasing proteasome activity and molecular chaperons in yeast and C. elegans. Here, we demonstrate the presence of similar responses in humans. Mitochondrial dysfunction upregulates a small heat shock protein HSPB1 and an immunoproteasome subunit PSMB9 leading to an increase in proteasome activity. HSPB1 and PSMB9 are required to prevent protein aggregation upon mitochondrial dysfunction. Moreover, PSMB9 expression is dependent on a translation elongation factor EEF1A2, and PSMB9-containing proteasomes are located near mitochondria, enabling fast local degradation of aberrant proteins. Our findings put a step forward in understanding the stress response triggered by mitochondrial dysfunction, and may be useful for therapeutic strategies to prevent or delay the onset of age-related diseases and attenuate their progression.

2021 ◽  
Vol 7 (12) ◽  
pp. 1102
Viridiana Magaña-Dueñas ◽  
José Francisco Cano-Lira ◽  
Alberto Miguel Stchigel

The Dothideomycetes are a class of cosmopolitan fungi that are present principally in terrestrial environments, but which have also been found in freshwater and marine habitats. In the present study, more than a hundred samples of plant debris were collected from various freshwater locations in Spain. Its incubation in wet chambers allowed us to detect and to isolate in pure culture numerous fungi producing asexual reproductive fruiting bodies (conidiomata). Thanks to a morphological comparison and to a phylogenetic analysis that combined the internal transcribed spacer (ITS) region of the nrDNA with fragments of the RNA polymerase II subunit 2 (rpb2), beta tubulin (tub2), and the translation elongation factor 1-alpha (tef-1) genes, six of those strains were identified as new species to science. Three belong to the family Didymellaceae: Didymella brevipilosa, Heterophoma polypusiformis and Paraboeremia clausa; and three belong to the family Phaeosphaeriaceae:Paraphoma aquatica, Phaeosphaeria fructigena and Xenophoma microspora. The finding of these new taxa significantly increases the number of the coelomycetous fungi that have been described from freshwater habitats.

2021 ◽  
Liang Xue ◽  
Swantje Lenz ◽  
Maria Zimmermann-Kogadeeva ◽  
Dimitry Tegunov ◽  
Patrick Cramer ◽  

Translation is the fundamental process of protein synthesis and is catalysed by the ribosome in all living cells. Here, we use cryo-electron tomography and sub-tomogram analysis to visualize the dynamics of translation inside the prokaryote Mycoplasma pneumoniae. We first obtain an in-cell atomic model for the M. pneumoniae ribosome that reveals distinct extensions of ribosomal proteins. Classification then resolves thirteen ribosome states that differ in conformation and composition and reflect intermediates during translation. Based on these states, we animate translation elongation and demonstrate how antibiotics reshape the translation landscape inside cells. During translation elongation, ribosomes often arrange in a defined manner to form polysomes. By mapping the intracellular three-dimensional organization of translating ribosomes, we show that their association into polysomes exerts a local coordination mechanism that is mediated by the ribosomal protein L9. Our work demonstrates the feasibility of visualizing molecular processes at atomic detail inside cells.

RNA ◽  
2021 ◽  
pp. rna.078964.121
Lisa Houston ◽  
Evan M Platten ◽  
Sara M Connelly ◽  
Jiyu Wang ◽  
Elizabeth J Grayhack

Ribosome stalls can result in ribosome collisions that elicit quality control responses, one function of which is to prevent ribosome frameshifting, an activity that entails interaction of the conserved yeast protein Mbf1 with uS3 on colliding ribosomes. However, the full spectrum of factors that mediate frameshifting during ribosome collisions is unknown. To delineate such factors in the yeast Saccharomyces cerevisiae, we used genetic selections for mutants that affect frameshifting from a known ribosome stall site, CGA codon repeats. We show that the general translation elongation factor eEF3 and the Integrated Stress Response (ISR) pathway components Gcn1 and Gcn20 modulate frameshifting in opposing manners. We found a mutant form of eEF3 that specifically suppressed frameshifting, but not translation inhibition by CGA codons. Thus, we infer that frameshifting at collided ribosomes requires eEF3, which facilitates tRNA-mRNA translocation and E-site tRNA release in yeast and other single cell organisms. By contrast, we found that removal of either Gcn1 or Gcn20, which bind collided ribosomes with Mbf1, increased frameshifting. Thus, we conclude that frameshifting is suppressed by Gcn1 and Gcn20, although these effects are not mediated primarily through activation of the ISR. Furthermore, we examined the relationship between eEF3-mediated frameshifting and other quality control mechanisms, finding that Mbf1 requires either Hel2 or Gcn1 to suppress frameshifting with wild type eEF3. Thus, these results provide evidence of a direct link between translation elongation and frameshifting at collided ribosomes, as well as evidence that frameshifting is constrained by quality control mechanisms that act on collided ribosomes.

2021 ◽  
Vol 7 (12) ◽  
pp. 1080
Lingling Li ◽  
Qin Yang ◽  
He Li

Tea-oil tree (Camellia oleifera) is an important edible oil woody plant with a planting area of over 3,800,000 hectares in southern China. Pestalotioid fungi are associated with a wide variety of plants worldwide along with endophytes, pathogens, and saprobes. In this study, symptomatic leaves of C. oleifera were collected from Guangdong, Guangxi, Hainan, Hunan, and Jiangsu Provinces and pestalotioid fungi are characterized based on combined sequence data analyses of internal transcribed spacer (ITS), beta tubulin (tub2), and translation elongation factor 1-alpha (tef-1α) coupled with morphological characteristics. As a result, seven species were confirmed, of which five species are described as new viz. N. camelliae-oleiferae, P. camelliae-oleiferae, P. hunanensis, P. nanjingensis, P. nanningensis, while the other two are reported as known species, viz., N. cubana and N. iberica. Pathogenicity assays showed that all species except for P. nanjingensis developed brown lesions on healthy leaves and P. camelliae-oleiferae showed stronger virulence.

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