The Clp1 Protein Is Required for Clamp Formation and Pathogenic Development of<i>Ustilago maydis</i>

Scherer, Mario; Heimel, Kai; Starke, V.; Kämper, Jörg

doi:10.1105/tpc.106.043521

Cited by 97 publications

(190 citation statements)

References 64 publications

Supporting

Mentioning

177

Contrasting

Unclassified

Order By: Relevance

“…It has recently been shown for example, that the b-regulated gene clp1, which is involved in cell cycle control during hyphal growth, is transcriptionally up-regulated immediately after b-locus induction. On the protein level, however, Clp1 is first observed upon plant penetration [9]. Protein accumulation results from the equilibrium between synthesis and degradation and thus posttranscriptional and/or posttranslational processes affect the protein level.…”

Section: Introductionmentioning

confidence: 99%

Proteomic analysis of dimorphic transition in the phytopathogenic fungus Ustilago maydis

et al. 2007

View full text Add to dashboard Cite

In the corn smut fungus Ustilago maydis, the dimorphic transition from budding to filamentous growth is intrinsically associated with the switch from a saprophytic to a pathogenic lifestyle. Both pathogenicity and filament formation are triggered by a heterodimeric homeodomain transcription factor encoded by the b mating type locus. Here, we present a reference map of the proteome of this dimorphic phytopathogenic fungus. Using 2-DE in combination with MALDI-TOF-MS and ESI-MS/MS, we were able to identify 250 distinct proteins obtained from soluble protein samples. In addition, we determined the abundance of cytosolic proteins in filamentous U. maydis cells and compared it with that of budding cells. Filamentous growth was induced by two independent regimes, either by overexpression of the bW2/bE1-heterodimer or by overexpression of the small GTP binding protein Rac1. By comparison of expression profiles, we have identified 13 protein spots that were significantly enhanced during filamentous growth induced by bW2/bE1. Rac1 only up-regulates a subset of four of these protein spots. None of these proteins have previously been associated with filamentous growth. Comparison of Rac1-and bregulated protein sets supports the hypothesis that filament formation during pathogenic development occurs via stimulation of a Rac1-containing signalling module.

show abstract

Section: Introductionmentioning

confidence: 99%

Proteomic analysis of dimorphic transition in the phytopathogenic fungus Ustilago maydis

et al. 2007

View full text Add to dashboard Cite

show abstract

“…Another candidate for Khd4 regulation is AUACCC-containing mRNA clp1 encoding a key factor of clamp formation, which is essential for pathogenicity. Consistently, Clp1 expression is regulated most likely at the translational level during plant penetration (Scherer et al 2006). A more detailed analysis of Khd4 targets will be critical to address these questions.…”

Section: What Is the Cellular Role Of Khd4?mentioning

confidence: 95%

“…In order to address this experimentally we investigated whether mRNAs were differentially expressed in the absence of Khd4. Using Affymetrix microarrays (Scherer et al 2006;Zarnack et al 2008; see Materials and Methods), we compared the expression profiles of FB2khd4D and wildtype strain FB2 in two independent transformants and two replicates growing in minimal medium, respectively (Supplemental Table S2). Seventy-two mRNAs were differentially expressed (1.5% of 4786 detected transcripts), whose abundance was significantly changed at least twofold in the deletion strain.…”

Section: Drfumentioning

confidence: 99%

See 1 more Smart Citation

Tandem KH domains of Khd4 recognize AUACCC and are essential for regulation of morphology as well as pathogenicity inUstilago maydis

Vollmeister¹,

Haag²,

Zarnack³

et al. 2009

RNA

View full text Add to dashboard Cite

RNA-binding proteins constitute key factors of the post-transcriptional machinery. These regulatory proteins recognize specific elements within target transcripts to promote, for example, maturation, translation, or stability of mRNAs. In Ustilago maydis, evidence is accumulating that post-transcriptional processes are important to determine pathogenicity. Deletion of khd4, encoding a predicted RNA-binding protein with five K homology (KH) domains, causes aberrant cell morphology and reduced virulence. Here, we demonstrate that Khd4 recognizes the sequence AUACCC in vivo via its tandem KH domains 3 and 4. This sequence most likely functions as a regulatory RNA element in U. maydis, since it accumulates in 39 untranslated regions. Consistently, an independent mRNA expression profiling approach revealed that the binding motif is significantly enriched in transcripts showing altered expression levels in khd4D strains. Since the vast majority of potential Khd4 target mRNAs exhibit increased amounts in deletion mutants, Khd4 might promote mRNA instability. Mutants that fail to bind AUACCC resemble deletion mutants, which exhibit altered cell morphology, disturbed filamentous growth, and severely reduced virulence. Hence, RNA binding is essential for function of Khd4, stressing the importance of post-transcriptional control in regulating morphology and pathogenicity.

show abstract

“…The qRT-PCR procedure with separate cDNA synthesis step was performed according to the manufacturer's instructions using the Superscript III Platinum two-step qRT-PCR kit with SYBR Green (Invitrogen) in an Applied Biosystems 7500 thermal cycler (Invitrogen). Ustilago peptidyl-prolyl isomerase (ppi) (GenBank NW_101009, locus UM03726.1) was used as a constitutively expressed reference gene (19,20). Primers used for the amplification of histone genes (see Fig.…”

Section: Methodsmentioning

confidence: 99%

Identification of a Replication-independent Replacement Histone H3 in the Basidiomycete Ustilago maydis

Verma

Kapros

Waterborg

2011

Journal of Biological Chemistry

View full text Add to dashboard Cite

Ustilago maydis is a haploid basidiomycete with single genes for two distinct histone H3 variants. The solitary U1 gene codes for H3.1, predicted to be a replication-independent replacement histone. The U2 gene is paired with histone H4 and produces a putative replication-coupled H3.2 variant. These predictions were evaluated experimentally. U2 was confirmed to be highly expressed in the S phase and had reduced expression in hydroxyurea, and H3.2 protein was not incorporated into transcribed chromatin of stationary phase cells. Constitutive expression of U1 during growth produced ϳ25% of H3 as H3.1 protein, more highly acetylated than H3.2. The level of H3.1 increased when cell proliferation slowed, a hallmark of replacement histones. Half of new H3.1 incorporated into highly acetylated chromatin was lost with a half-life of 2.5 h, the fastest rate of replacement H3 turnover reported to date. This response reflects the characteristic incorporation of replacement H3 into transcribed chromatin, subject to continued nucleosome displacement and a loss of H3 as in animals and plants. Although the two H3 variants are functionally distinct, neither appears to be essential for vegetative growth. KO gene disruption transformants of the U1 and U2 loci produced viable cell lines. The structural and functional similarities of the Ustilago replication-coupled and replication-independent H3 variants with those in animals, in plants, and in ciliates are remarkable because these distinct histone H3 pairs of variants arose independently in each of these clades and in basidiomycetes.Core histones provide the packaging proteins for DNA in eukaryotic cells. During the S phase when genomic DNA is duplicated, replication-coupled expression of histone genes provides new protein to assemble newly replicated DNA. Histone chaperones assist in the creation of new nucleosomes to maintain a stable, compacted, repressed state of chromatin. Within this context, regulatory proteins modulate chromatin environments to facilitate access to the DNA for gene transcription. The components and processes that allow RNA polymerases to transcribe a chromatin template, such as epigenetic modifications of DNA and histones, are being identified and intensely studied. The processes of nucleosome displacement from DNA by transcribing RNA polymerases and of nucleosome reassembly from available histones remain poorly understood.In research going back decades, it was observed that the composition of nucleosomes across transcribed gene regions, identified in part by high levels of histone acetylation, changed over time. Replication-coupled (RC) 2 histone H3 variants like H3.2 in birds were replaced by histone H3.3, a constitutively expressed form of animal histone H3. This histone is now known as a replacement histone or as a replication-independent (RI) H3 variant (1, 2). Specialized chaperones such as HIRA and Daxx selectively bind these RI H3 proteins at a small region, residues 87-90, which is uniquely different between RI and RC forms (3, 4). In the S phase...

show abstract

The Clp1 Protein Is Required for Clamp Formation and Pathogenic Development ofUstilago maydis

Cited by 97 publications

References 64 publications

Proteomic analysis of dimorphic transition in the phytopathogenic fungus Ustilago maydis

Proteomic analysis of dimorphic transition in the phytopathogenic fungus Ustilago maydis

Tandem KH domains of Khd4 recognize AUACCC and are essential for regulation of morphology as well as pathogenicity inUstilago maydis

Identification of a Replication-independent Replacement Histone H3 in the Basidiomycete Ustilago maydis

Contact Info

Product

Resources

About