scholarly journals Molecular studies of NAD- and NADP- glutamate dehydrogenases decipher the conundrum of yeast-hypha dimorphism in zygomycete Benjaminiella poitrasii

2019 ◽  
Author(s):  
E K Pathan ◽  
V Ghormade ◽  
S Panwar ◽  
R Prasad ◽  
M V Deshpande

Abstract Benjaminiella poitrasii, a zygomycete shows glucose and temperature dependent yeast (Y)-hypha (H) dimorphic transition. Earlier we reported the biochemical correlation of relative proportion of NAD- and NADP- glutamate dehydrogenases (GDH) with Y-H transition. Further, we observed the presence of one NAD-GDH and two form–specific NADP-GDH isoenzymes in B. poitrasii. However, molecular studies are necessary to elucidate the explicit role of GDHs in regulating Y-H reversible transition. Here, we report the isolation and characterization of one NAD- (BpNADGDH, 2.643 kb) and two separate genes, BpNADPGDH I (Y form specific, 1.365 kb) and BpNADPGDH II (H form specific, 1.368 kb) coding for NADP-GDH isoenzymes in B. poitrasii. The transcriptional profiling during Y-H transition showed higher BpNADPGDH I expression in Y cells while expression of BpNADPGDH II was higher in H cells. Moreover, the yeast form monomorphic mutant (Y-5) did not show BpNADPGDH II expression under normal dimorphism triggering conditions. Transformation with H form specific BpNADPGDH II induced the germ tube formation in Y-5, which confirmed the cause-effect relationship between BpNADPGDH genes and morphological outcome in B. poitrasii. Interestingly, expression of H-form specific BpNADPGDH II also induced germ tube formation in human pathogenic, non-dimorphic yeast Candida glabrata, which further corroborated our findings.

1981 ◽  
Vol 27 (6) ◽  
pp. 580-585 ◽  
Author(s):  
Louise A. Brown ◽  
W. LaJean Chaffin

Changes in the identity and quantity of proteins synthesized during morphogenesis may result from alterations in gene expression in the dimorphic yeast Candida albicans. Stationary phase yeast cells, upon resuming growth at 25 °C, form budding yeast and at 37 °C form germ tubes. In order to identify proteins associated with morphogenesis, we compared cytoplasmic proteins synthesized during germ tube and bud formation. Proteins synthesized during this period were labeled at four intervals with either [3H]leucine or [35S]methionine and separated by two-dimensional polyacrylamide gel electrophoresis. This study shows that, of the 230 proteins resolved on each gel, 5 were specific to the yeast morphology and 2 proteins showed reduction in net synthesis in the mycelial phase. There were, however, no mycelium-specific proteins at any labeling period. The majority of proteins were common to both morphologies and showed no major shift in number during resumption of growth. The observations reported here suggest that differential gene expression occurs during morphogenesis of C. albicans.


1999 ◽  
Vol 45 (4, Part 2 of 2) ◽  
pp. 156A-156A
Author(s):  
Catherine M Bendel ◽  
Karen K Kinneberg ◽  
Robert P Jechorek ◽  
Margaret K Hostetter ◽  
Stanley L Erlandsen ◽  
...  

1984 ◽  
Vol 44 (3) ◽  
pp. 576-580 ◽  
Author(s):  
J D Sobel ◽  
G Muller ◽  
H R Buckley

2004 ◽  
Vol 164 (4) ◽  
pp. 581-591 ◽  
Author(s):  
Raymond Wightman ◽  
Steven Bates ◽  
Pat Amornrrattanapan ◽  
Peter Sudbery

In the development of hyphal germ tubes of Candida albicans, a band of septin forms at the base of the germ tube (basal septin band). Later, a septin ring forms, which organizes the first septum within the germ tube (septin ring). We have investigated the role of the Nim1 kinases, Gin4 and Hsl1, in the formation of these septin structures. We show that during germ tube formation, Gin4 is required for the organization of the septin ring but not the basal septin band. Hsl1 is not required for the formation of either septin rings or basal bands. Unexpectedly, we found that both gin4Δ and hsl1Δ mutants form pseudohyphae constitutively, in a fashion that in the case of gin4Δ, is partly independent of Swe1. Gin4-depleted pseudohyphae are unable to form hyphae when challenged with serum, but this can be overcome by ectopic expression of Gin4 from the MET3 promoter. Thus, Gin4 may regulate the developmental switch from pseudohyphae to hyphae.


1985 ◽  
Vol 73 (1) ◽  
pp. 207-220
Author(s):  
K. Tanaka ◽  
T. Kanbe ◽  
T. Kuroiwa

This study was done to correlate mitochondrial behaviour with nuclear behaviour and cell division as well as with the germ tube formation in the dimorphic yeast Candida albicans. Three-dimensional reconstruction of electron micrographs of serially sectioned cells of the three strains was used to determined the morphological and quantitative relationships between the structures. The results suggested that at the time of entry into the bud a few mitochondria fused into a single giant one, which fragmented during mitosis and resumed a single giant form before cytokinesis, and was then partitioned into two parts. This tendency was also shown during germ tube formation. Quantitative analysis has established that growth of organelles such as the nucleus and mitochondria closely followed total cell growth, the ratio of organelle volume to total cell volume being held relatively constant.


Gut ◽  
2021 ◽  
pp. gutjnl-2020-323363
Author(s):  
Ester Pagano ◽  
Joshua E Elias ◽  
Georg Schneditz ◽  
Svetlana Saveljeva ◽  
Lorraine M Holland ◽  
...  

ObjectivePrimary sclerosing cholangitis (PSC) is in 70% of cases associated with inflammatory bowel disease. The hypermorphic T108M variant of the orphan G protein-coupled receptor GPR35 increases risk for PSC and ulcerative colitis (UC), conditions strongly predisposing for inflammation-associated liver and colon cancer. Lack of GPR35 reduces tumour numbers in mouse models of spontaneous and colitis associated cancer. The tumour microenvironment substantially determines tumour growth, and tumour-associated macrophages are crucial for neovascularisation. We aim to understand the role of the GPR35 pathway in the tumour microenvironment of spontaneous and colitis-associated colon cancers.DesignMice lacking GPR35 on their macrophages underwent models of spontaneous colon cancer or colitis-associated cancer. The role of tumour-associated macrophages was then assessed in biochemical and functional assays.ResultsHere, we show that GPR35 on macrophages is a potent amplifier of tumour growth by stimulating neoangiogenesis and tumour tissue remodelling. Deletion of Gpr35 in macrophages profoundly reduces tumour growth in inflammation-associated and spontaneous tumour models caused by mutant tumour suppressor adenomatous polyposis coli. Neoangiogenesis and matrix metalloproteinase activity is promoted by GPR35 via Na/K-ATPase-dependent ion pumping and Src activation, and is selectively inhibited by a GPR35-specific pepducin. Supernatants from human inducible-pluripotent-stem-cell derived macrophages carrying the UC and PSC risk variant stimulate tube formation by enhancing the release of angiogenic factors.ConclusionsActivation of the GPR35 pathway promotes tumour growth via two separate routes, by directly augmenting proliferation in epithelial cells that express the receptor, and by coordinating macrophages’ ability to create a tumour-permissive environment.


2021 ◽  
Vol 22 (8) ◽  
pp. 3982
Author(s):  
Karolina Kotecka ◽  
Adam Kawalek ◽  
Kamil Kobylecki ◽  
Aneta Agnieszka Bartosik

Pseudomonas aeruginosa is a facultative human pathogen, causing acute and chronic infections that are especially dangerous for immunocompromised patients. The eradication of P. aeruginosa is difficult due to its intrinsic antibiotic resistance mechanisms, high adaptability, and genetic plasticity. The bacterium possesses multilevel regulatory systems engaging a huge repertoire of transcriptional regulators (TRs). Among these, the MarR family encompasses a number of proteins, mainly acting as repressors, which are involved in response to various environmental signals. In this work, we aimed to decipher the role of PA3458, a putative MarR-type TR from P. aeruginosa. Transcriptional profiling of P. aeruginosa PAO1161 overexpressing PA3458 showed changes in the mRNA level of 133 genes; among them, 100 were down-regulated, suggesting the repressor function of PA3458. Concomitantly, ChIP-seq analysis identified more than 300 PA3458 binding sites in P. aeruginosa. The PA3458 regulon encompasses genes involved in stress response, including the PA3459–PA3461 operon, which is divergent to PA3458. This operon encodes an asparagine synthase, a GNAT-family acetyltransferase, and a glutamyl aminopeptidase engaged in the production of N-acetylglutaminylglutamine amide (NAGGN), which is a potent bacterial osmoprotectant. We showed that PA3458-mediated control of PA3459–PA3461 expression is required for the adaptation of P. aeruginosa growth in high osmolarity. Overall, our data indicate that PA3458 plays a role in osmoadaptation control in P. aeruginosa.


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