The Aspergillus nidulans GATA Factor SREA Is Involved in Regulation of Siderophore Biosynthesis and Control of Iron Uptake

1,409

1,302

SUMMARY High-affinity iron acquisition is mediated by siderophore-dependent pathways in the majority of pathogenic and nonpathogenic bacteria and fungi. Considerable progress has been made in characterizing and understanding mechanisms of siderophore synthesis, secretion, iron scavenging, and siderophore-delivered iron uptake and its release. The regulation of siderophore pathways reveals multilayer networks at the transcriptional and posttranscriptional levels. Due to the key role of many siderophores during virulence, coevolution led to sophisticated strategies of siderophore neutralization by mammals and (re)utilization by bacterial pathogens. Surprisingly, hosts also developed essential siderophore-based iron delivery and cell conversion pathways, which are of interest for diagnostic and therapeutic studies. In the last decades, natural and synthetic compounds have gained attention as potential therapeutics for iron-dependent treatment of infections and further diseases. Promising results for pathogen inhibition were obtained with various siderophore-antibiotic conjugates acting as “Trojan horse” toxins and siderophore pathway inhibitors. In this article, general aspects of siderophore-mediated iron acquisition, recent findings regarding iron-related pathogen-host interactions, and current strategies for iron-dependent pathogen control will be reviewed. Further concepts including the inhibition of novel siderophore pathway targets are discussed.

Section: Gene Regulation Of Microbial Iron Homeostasismentioning

confidence: 99%

Siderophore-Based Iron Acquisition and Pathogen Control

Miethke

Marahiel

2007

1,409

1,302

“…However, the TF NMRA of T. atroviride (TA_35890; containing an NADP Rossman fold domain), a negative regulator of the Nit-2 ortholog AreA in A. nidulans (389), is induced in the presence of light (1313). Another GATA factor not yet characterized in T. atroviride (TA_174504), T. virens (TV_192933), or T. reesei (TR_4231) is sre (siderophore regulation), which is involved in the uptake of iron in N. crassa and A. nidulans (1068,1069). In Trichoderma spp., siderophores are considered part of the biocontrol mechanism against phytopathogenic fungi and in the enhancement of plant growth (8,1070).…”

Section: Gata-type Zinc Finger Transcription Factorsmentioning

confidence: 99%

The Genomes of Three Uneven Siblings: Footprints of the Lifestyles of Three Trichoderma Species

Schmoll

Dattenböck

Carreras-Villaseñor

et al. 2016

163

195

SUMMARYThe genusTrichodermacontains fungi with high relevance for humans, with applications in enzyme production for plant cell wall degradation and use in biocontrol. Here, we provide a broad, comprehensive overview of the genomic content of these species for “hot topic” research aspects, including CAZymes, transport, transcription factors, and development, along with a detailed analysis and annotation of less-studied topics, such as signal transduction, genome integrity, chromatin, photobiology, or lipid, sulfur, and nitrogen metabolism inT. reesei,T. atroviride, andT. virens, and we open up new perspectives to those topics discussed previously. In total, we covered more than 2,000 of the predicted 9,000 to 11,000 genes of eachTrichodermaspecies discussed, which is >20% of the respective gene content. Additionally, we considered available transcriptome data for the annotated genes. Highlights of our analyses include overall carbohydrate cleavage preferences due to the different genomic contents and regulation of the respective genes. We found light regulation of many sulfur metabolic genes. Additionally, a new Golgi 1,2-mannosidase likely involved inN-linked glycosylation was detected, as were indications for the ability ofTrichodermaspp. to generate hybrid galactose-containingN-linked glycans. The genomic inventory of effector proteins revealed numerous compounds unique toTrichoderma, and these warrant further investigation. We found interesting expansions in theTrichodermagenus in several signaling pathways, such as G-protein-coupled receptors, RAS GTPases, and casein kinases. A particularly interesting feature absolutely unique toT. atrovirideis the duplication of the alternative sulfur amino acid synthesis pathway.

“…This GATA factor has two zinc fingers and sequence similarity to several fungal proteins, SreP from P. chrysogenum, UrbS from U. maydis, and SreA from A. nidulans. All are negative regulators of siderophore synthesis (317,318,835). SRE negatively regulates siderophore production in Neurospora (898).…”

Section: Transcription Factorsmentioning

confidence: 99%

Lessons from the Genome Sequence ofNeurospora crassa: Tracing the Path from Genomic Blueprint to Multicellular Organism

Borkovich

Alex

Yarden

et al. 2004

593

618

We present an analysis of over 1,100 of the ∼10,000 predicted proteins encoded by the genome sequence of the filamentous fungus Neurospora crassa. Seven major areas of Neurospora genomics and biology are covered. First, the basic features of the genome, including the automated assembly, gene calls, and global gene analyses are summarized. The second section covers components of the centromere and kinetochore complexes, chromatin assembly and modification, and transcription and translation initiation factors. The third area discusses genome defense mechanisms, including repeat induced point mutation, quelling and meiotic silencing, and DNA repair and recombination. In the fourth section, topics relevant to metabolism and transport include extracellular digestion; membrane transporters; aspects of carbon, sulfur, nitrogen, and lipid metabolism; the mitochondrion and energy metabolism; the proteasome; and protein glycosylation, secretion, and endocytosis. Environmental sensing is the focus of the fifth section with a treatment of two-component systems; GTP-binding proteins; mitogen-activated protein, p21-activated, and germinal center kinases; calcium signaling; protein phosphatases; photobiology; circadian rhythms; and heat shock and stress responses. The sixth area of analysis is growth and development; it encompasses cell wall synthesis, proteins important for hyphal polarity, cytoskeletal components, the cyclin/cyclin-dependent kinase machinery, macroconidiation, meiosis, and the sexual cycle. The seventh section covers topics relevant to animal and plant pathogenesis and human disease. The results demonstrate that a large proportion of Neurospora genes do not have homologues in the yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe. The group of unshared genes includes potential new targets for antifungals as well as loci implicated in human and plant physiology and disease