Research, Research Articles
Overcoming phagocytosis resistance of hypervirulent Klebsiella pneumoniae by directly targeting capsules
Shogo Tsubaki1, Touya Toyomoto1, Rika Tanaka2,3, Jin Imai4,5, Juntaro Matsuzaki6,7, Katsuto Hozumi2 and Hitoshi Tsugawa1,5*
This study highlights a promising strategy for disarming hypervirulent K. pneumoniae by directly targeting its key virulence factors and provides novel insights into antibacterial therapeutic approaches against this clinically significant pathogen.
VapA/Scs2 sustains polarized growth in Aspergillus nidulans by maintaining AP-2-mediated apical endocytosis
Xenia Georgiou1, Sofia Politi1, Sotiris Amillis1 and George Diallinas1,2,*
To explore the functional significance of ER–PM contact sites in filamentous fungi, we identified and genetically characterized all Aspergillus nidulans proteins homologous to Snc2/VAP, Ist2, or tricalbins.
Genetic make-up and regulation of the L-lysine biosynthesis pathway in Vibrio natriegens
Elly Straube1, Johannes Radde1, Thi Van Anh Tran1, Negin Keihani Yazdi1, Rubén Crespo Blanco1, Ha Thanh Le2, Cláudio J.R. Frazão1 and Thomas Walther1,*
This study analysed the make-up and regulation of the biosynthetic pathway for L-lysine and related L-aspartate family amino acids (AFAAs) in Vibrio natriegens DSM759 to provide a comprehensive basis for future metabolic engineering endeavours aiming at developing this strain into an amino acid overproducer.
Regulation of extracellular vesicles for protein secretion in Aspergillus nidulans
Rebekkah E. Pope1, Patrick Ballmann2, Lisa Whitworth3 and Rolf A. Prade1,*
This study reveals that Aspergillus nidulans boosts extracellular vesicle production when ER-trafficked enzymes are induced, uncovering how fungi remodel their secretome through vesicle-mediated secretion to adapt to changing environments and biofilm formation.
Transcriptomic response to different heme sources in Trypanosoma cruzi epimastigotes
Evelyn Tevere1,a, María G. Mediavilla1,a, Cecilia B. Di Capua1, Marcelo L. Merli1, Carlos Robello2,3, Luisa Berná2,4 and Julia A. Cricco
This study uncovers how the Chagas disease parasite adapts to changes in heme, an essential molecule for its survival, providing transcriptional clues to heme metabolism and identifying a previously unreported heme-binding protein in T. cruzi.
Sir2 regulates selective autophagy in stationary-phase yeast cells
Ji-In Ryua, Juhye Junga, and Jeong-Yoon Kim
This study establishes Sir2 as a previously unrecognized regulator of selective autophagy during the stationary phase and highlight how cells dynamically control organelle degradation.
Luminal acetylation of microtubules is not essential for Plasmodium berghei and Toxoplasma gondii survival
Thrishla Kumar1,a, Katharina Röver2,a, Johannes F. Stortz3,a, Annika M. Binder2,a, Benjamin Spreng2, Madlen Konert2, Markus Meissner1, Friedrich Frischknecht2,4 and Elena Jimenez-Ruiz1,*
Acetylation of α-tubulin at lysine 40 is not essential for cytoskeletal stability in Plasmodium berghei or Toxoplasma gondii, suggesting redundancy and plasticity in microtubule regulation in these parasites.
The dual-site agonist for human M2 muscarinic receptors Iper-8-naphtalimide induces mitochondrial dysfunction in Saccharomyces cerevisiae
Angela Cirigliano1,a, Antonia Amelina2,a, Elena Passarini2, Alessandra Ricelli1, Nicole Balasco1, Mattia Mori3, Bruno Botta4, Maria Egle De Stefano2,5, Claudio Papotto6, Claudia Guerriero2, Ada Maria Tata2,5 and Teresa Rinaldi2,*
S. cerevisiae is a model to study human GPCRs. N-8-Iper, active against glioblastoma via M2 receptor, causes mitochondrial damage in yeast by binding Ste2, highlighting evolutionary conservation of GPCRs.
VDAC regulates AAC-mediated apoptosis and cytochrome c release in yeast
August 25, 2016
Mitochondrial outer membrane permeabilization is a key event in apoptosis processes leading to the release of lethal factors. In this study, we sought to determine whether Por1p functionally interacts with ADP/ATP carrier (AAC) proteins, as well as its contribution to cytochrome c release and yeast apoptosis induced by acetic acid treatment. Our data indicate that Por1p may regulate cell survival by acting as a negative regulator of AAC proteins in the apoptotic cascade.
Attenuation of polyglutamine-induced toxicity by enhancement of mitochondrial OXPHOS in yeast and fly models of aging
July 26, 2016
Defects in mitochondrial biogenesis and function are common in many neurodegenerative disorders, including Huntington’s disease (HD). We could shown that enhancement of mitochondrial biogenesis protects against neurodegeneration in HD yeast and fly models. Our results suggest that therapeutic interventions aiming at the enhancement of mitochondrial respiration and OXPHOS could reduce polyQ toxicity and delay disease onset.
Cox1 mutation abrogates need for Cox23 in cytochrome c oxidase biogenesis
June 30, 2016
Cox23 is a known conserved assembly factor for cytochrome c oxidase, although its role in cytochrome c oxidase (CcO) biogenesis remains unresolved. To gain additional insights into its role, we isolated spontaneous suppressors of the respiratory growth defect in cox23∆ yeast cells. In this report, we describe the isolation of a robust suppressor of the respiratory defect in cox23∆ cells that mapped to the mitochondrial-encoded Cox1 subunit.
Construction and evaluation of yeast expression networks by database-guided predictions
May 10, 2016
DNA-Microarrays are powerful tools to obtain expression data on the genome-wide scale. We set out to define a way to cluster microarray data according to their expressional relationship and to obtain information on the significance of this clustering approach.
Optogenetic monitoring identifies phosphatidylthreonine-regulated calcium homeostasis in Toxoplasma gondii
May 1, 2016
Toxoplasma gondii is an obligate intracellular parasite, which inflicts acute as well as chronic infections in a wide range of warm-blooded vertebrates. Using an optogenetic sensor to monitor subcellular calcium in this model intracellular pathogen we found a novel regulatory function of phosphatidylthreonine in calcium signaling.
Formaldehyde fixation is detrimental to actin cables in glucose-depleted S. cerevisiae cells
April 13, 2016
Actin filaments form cortical patches and emanating cables in fermenting cells of Saccharomyces cerevisiae. We assume that stability of actin cables reflects the metabolic status of the cell. Based on comparison of live and formaldehyde-fixed cells, our data suggest that formaldehyde affects respiration before fixation and this uneven signaling results in destabilization of actin cables in glucose-deprived cells.
Insights into dynamin-associated disorders through analysis of equivalent mutations in the yeast dynamin Vps1
March 22, 2016
The dynamins represent a superfamily of proteins that have been shown to function in a wide range of membrane fusion and fission events. An increasing number of mutations in the human classical dynamins, Dyn-1 and Dyn-2 has been reported, with diseases caused by these changes ranging from Charcot-Marie-Tooth disorder to epileptic encephalopathies. This study aimed to use the dynamin-like protein Vps1 of Saccharomyces cerevisiae as a model to gain insights into the mechanistic defects caused by specific dynamin mutations considered to underlie a number of diseases.
Genomic saturation mutagenesis and polygenic analysis identify novel yeast genes affecting ethyl acetate production, a non-selectable polygenic trait
March 18, 2016
Isolation of mutants in populations of microorganisms has been a valuable tool in experimental genetics for decades. The main disadvantage, however, is the inability of isolating mutants in non-selectable polygenic traits. Our study shows that genomic saturation mutagenesis combined with complex trait polygenic analysis could be used successfully to identify causative alleles underlying many non-selectable, polygenic traits in small collections of haploid strains with multiple induced mutations.
Differentiated cytoplasmic granule formation in quiescent and non-quiescent cells upon chronological aging
March 3, 2016
Stationary phase cultures represent a complicated cell population comprising at least two different cell types, quiescent (Q) and non-quiescent (NQ) cells. The authors show that the cell fate of NQ cells is largely irreversible even if they are allowed to reenter mitosis. Their results reveal that the formation of different granule structures may represent the early stage of cell type differentiation in yeast stationary phase cultures.
Mitochondrial proteomics of the acetic acid – induced programmed cell death response in a highly tolerant Zygosaccharomyces bailii – derived hybrid strain
January 22, 2016
Very high concentrations of acetic acid at low pH induce programmed cell death (PCD) in both the experimental model Saccharomyces cerevisiae and in Zygosaccharomyces bailii, the latter being considered the most problematic acidic food spoilage yeast due to its remarkable intrinsic resistance to this food preservative. This study offers insights into the mechanisms involved in acetic acid - induced PCD in the Z. bailii-derived hybrid strain ISA1307 by analyzing the yeast mitochondrial protein expression profile of cells challenged by acetic acid.