scholarly journals Candida albicans hyphal morphogenesis occurs in Sec3p-independent and Sec3p-dependent phases separated by septin ring formation

2007 ◽  
Vol 120 (11) ◽  
pp. 1898-1907 ◽  
Author(s):  
C.-R. Li ◽  
R. T.-H. Lee ◽  
Y.-M. Wang ◽  
X.-D. Zheng ◽  
Y. Wang
Keyword(s):  
Candida Albicans ◽  
Ring Formation ◽  
Septin Ring ◽  
Hyphal Morphogenesis

scholarly journals Sep7 Is Essential to Modify Septin Ring Dynamics and Inhibit Cell Separation during Candida albicans Hyphal Growth

2008 ◽  
Vol 19 (4) ◽  
pp. 1509-1518 ◽  
Author(s):  
Alberto González-Novo ◽  
Jaime Correa-Bordes ◽  
Leticia Labrador ◽  
Miguel Sánchez ◽  
Carlos R. Vázquez de Aldana ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Cell Separation ◽  
Hyphal Growth ◽  
Yeast Cells ◽  
Septin Ring ◽  
Protein Levels ◽  
Hyphal Morphogenesis ◽  
Hypha Formation ◽  
Ring Dynamics ◽  
Cytoskeleton Dynamics

When Candida albicans yeast cells receive the appropriate stimulus, they switch to hyphal growth, characterized by continuous apical elongation and the inhibition of cell separation. The molecular basis of this inhibition is poorly known, despite its crucial importance for hyphal development. In C. albicans, septins are important for hypha formation and virulence. Here, we used fluorescence recovery after photobleaching analysis to characterize the dynamics of septin rings during yeast and hyphal growth. On hyphal induction, septin rings are converted to a hyphal-specific state, characterized by the presence of a frozen core formed by Sep7/Shs1, Cdc3 and Cdc12, whereas Cdc10 is highly dynamic and oscillates between the ring and the cytoplasm. Conversion of septin rings to the hyphal-specific state inhibits the translocation of Cdc14 phosphatase, which controls cell separation, to the hyphal septum. Modification of septin ring dynamics during hyphal growth is dependent on Sep7 and the hyphal-specific cyclin Hgc1, which partially controls Sep7 phosphorylation status and protein levels. Our results reveal a link between the cell cycle machinery and septin cytoskeleton dynamics, which inhibits cell separation in the filaments and is essential for hyphal morphogenesis.

scholarly journals The 65�kDa mannoprotein gene of Candida albicans encodes a putative ?-glucanase adhesin required for hyphal morphogenesis and experimental pathogenicity

2007 ◽  
Vol 9 (5) ◽  
pp. 1223-1238 ◽  
Author(s):  
Silvia Sandini ◽  
Roberto La Valle ◽  
Flavia De Bernardis ◽  
Caterina Macrì ◽  
Antonio Cassone
Keyword(s):  
Candida Albicans ◽  
Hyphal Morphogenesis ◽  
Experimental Pathogenicity

scholarly journals The 5’ untranslated region of theEFG1transcript promotes its translation to regulate hyphal morphogenesis inCandida albicans

2018 ◽  
Author(s):  
Prashant R. Desai ◽  
Klaus Lengeler ◽  
Mario Kapitan ◽  
Silas Matthias Janßen ◽  
Paula Alepuz ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Fungal Pathogen ◽  
Regulatory Mechanisms ◽  
Untranslated Regions ◽  
Regulatory Sequence ◽  
Transcriptional Level ◽  
Human Fungal Pathogen ◽  
Hyphal Morphogenesis ◽  
Cellular Morphogenesis ◽  
Incandida Albicans

ABSTRACTExtensive 5’ untranslated regions (UTR) are a hallmark of transcripts determining hyphal morphogenesis inCandida albicans.The major transcripts of theEFG1gene, which are responsible for cellular morphogenesis and metabolism, contain a 5’ UTR of up to 1170 nt. Deletion analyses of the 5’ UTR revealed a 218 nt sequence that is required for production of the Efg1 protein and its functions in filamentation, without lowering the level and integrity of theEFG1transcript. Polysomal analyses revealed that the 218 nt 5’ UTR sequence is required for efficient translation of the Efg1 protein. Replacement of theEFG1ORF by the heterologous reporter geneCaCBGlucconfirmed the positive regulatory importance of the identified 5’ UTR sequence. In contrast to other reported transcripts containing extensive 5’ UTR sequences, these results indicate the positive translational function of the 5’ UTR sequence in theEFG1transcript, which is observed in context of the nativeEFG1promoter. The results suggest that the 5’ UTR recruits regulatory factors, possibly during emergence of the native transcript, which aid in translation of theEFG1transcript.IMPORTANCEMany of the virulence traits that makeCandida albicansan important human fungal pathogen are regulated on a transcriptional level. Here we report an important regulatory contribution of translation, which is exerted by the extensive 5’ untranslated regulatory sequence (5’ UTR) of the transcript for the protein Efg1, which determines growth, metabolism and filamentation in the fungus. Presence of the 5’ UTR is required for efficient translation of Efg1, to promote filamentation. Because transcripts for many relevant regulators contain extensive 5’ UTR sequences, it appears that virulence ofC. albicansdepends on the combination of transcriptional and translation regulatory mechanisms.

scholarly journals Integrative multi-omics profiling reveals cAMP-independent mechanisms regulating hyphal morphogenesis in Candida albicans

2021 ◽  
Vol 17 (8) ◽  
pp. e1009861
Author(s):  
Kyunghun Min ◽  
Thomas F. Jannace ◽  
Haoyu Si ◽  
Krishna R. Veeramah ◽  
John D. Haley ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Adenylyl Cyclase ◽  
Regulatory Subunit ◽  
Chromosome 2 ◽  
Casein Kinase 1 ◽  
Hyphal Morphogenesis ◽  
Wide Range ◽  
Kinase A

Microbial pathogens grow in a wide range of different morphologies that provide distinct advantages for virulence. In the fungal pathogen Candida albicans, adenylyl cyclase (Cyr1) is thought to be a master regulator of the switch to invasive hyphal morphogenesis and biofilm formation. However, faster growing cyr1Δ/Δ pseudorevertant (PR) mutants were identified that form hyphae in the absence of cAMP. Isolation of additional PR mutants revealed that their improved growth was due to loss of one copy of BCY1, the negative regulatory subunit of protein kinase A (PKA) from the left arm of chromosome 2. Furthermore, hyphal morphogenesis was improved in some of PR mutants by multigenic haploinsufficiency resulting from loss of large regions of the left arm of chromosome 2, including global transcriptional regulators. Interestingly, hyphal-associated genes were also induced in a manner that was independent of cAMP. This indicates that basal protein kinase A activity is an important prerequisite to induce hyphae, but activation of adenylyl cyclase is not needed. Instead, phosphoproteomic analysis indicated that the Cdc28 cyclin-dependent kinase and the casein kinase 1 family member Yck2 play key roles in promoting polarized growth. In addition, integrating transcriptomic and proteomic data reveals hyphal stimuli induce increased production of key transcription factors that contribute to polarized morphogenesis.

scholarly journals The Ndr/LATS Kinase Cbk1 Regulates a Specific Subset of Ace2 Functions and Suppresses the Hypha-to-Yeast Transition in Candida albicans

mBio ◽  
2020 ◽  
Vol 11 (4) ◽  
Author(s):  
Rohan S. Wakade ◽  
Laura C. Ristow ◽  
Mark A. Stamnes ◽  
Anuj Kumar ◽  
Damian J. Krysan
Keyword(s):  
Candida Albicans ◽  
Regulatory Network ◽  
Transcriptional Analysis ◽  
Large Set ◽  
Phase Growth ◽  
Content Type ◽  
Hyphal Morphogenesis ◽  
Specific Subset ◽  
Wide Range ◽  
Yeast Phase

ABSTRACT The regulation of Ace2 and morphogenesis (RAM) pathway is an important regulatory network in the human fungal pathogen Candida albicans. The RAM pathway’s two most well-studied components, the NDR/Lats kinase Cbk1 and its putative substrate, the transcription factor Ace2, have a wide range of phenotypes and functions. It is not clear, however, which of these functions are specifically due to the phosphorylation of Ace2 by Cbk1. To address this question, we first compared the transcriptional profiles of CBK1 and ACE2 deletion mutants. This analysis indicates that, of the large number of genes whose expression is affected by deletion of CBK1 and ACE2, only 5.5% of those genes are concordantly regulated. Our data also suggest that Ace2 directly or indirectly represses a large set of genes during hyphal morphogenesis. Second, we generated strains containing ACE2 alleles with alanine mutations at the Cbk1 phosphorylation sites. Phenotypic and transcriptional analysis of these ace2 mutants indicates that, as in Saccharomyces cerevisiae, Cbk1 regulation is important for daughter cell localization of Ace2 and cell separation during yeast-phase growth. In contrast, Cbk1 phosphorylation of Ace2 plays a minor role in C. albicans yeast-to-hypha transition. We have, however, discovered a new function for the Cbk1-Ace2 axis. Specifically, Cbk1 phosphorylation of Ace2 prevents the hypha-to-yeast transition. To our knowledge, this is one of the first regulators of the C. albicans hypha-to-yeast transition to be described. Finally, we present an integrated model for the role of Cbk1 in the regulation of hyphal morphogenesis in C. albicans. IMPORTANCE The regulation of Ace2 and morphogenesis (RAM) pathway is a key regulatory network that plays a role in many aspects of C. albicans pathobiology. In addition to characterizing the transcriptional effects of this pathway, we discovered that Cbk1 and Ace2, a key RAM pathway regulator-effector pair, mediate a specific set of the overall functions of the RAM pathway. We have also discovered a new function for the Cbk1-Ace2 axis: suppression of the hypha-to-yeast transition. Very few regulators of this transition have been described, and our data indicate that maintenance of hyphal morphogenesis requires suppression of yeast phase growth by Cbk1-regulated Ace2.

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