scholarly journals Overexpression of the HECT ubiquitin ligase PfUT prolongs the intraerythrocytic cycle and reduces invasion efficiency of Plasmodium falciparum

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Monika Jankowska-Döllken ◽  
Cecilia P. Sanchez ◽  
Marek Cyrklaff ◽  
Michael Lanzer
Keyword(s):  
Plasmodium Falciparum ◽  
Ubiquitin Ligase ◽  
Cell Cycle Progression ◽  
Developmental Cycle ◽  
Unexpected Finding ◽  
Gene Encoding ◽  
Merozoite Invasion ◽  
Protein Levels ◽  
Expression Of Genes ◽  
Glms Ribozyme

AbstractThe glms ribozyme system has been used as an amenable tool to conditionally control expression of genes of interest. It is generally assumed that insertion of the ribozyme sequence does not affect expression of the targeted gene in the absence of the inducer glucosamine-6-phosphate, although experimental support for this assumption is scarce. Here, we report the unexpected finding that integration of the glms ribozyme sequence in the 3′ untranslated region of a gene encoding a HECT E3 ubiquitin ligase, termed Plasmodium falciparum ubiquitin transferase (PfUT), increased steady state RNA and protein levels 2.5-fold in the human malaria parasite P. falciparum. Overexpression of pfut resulted in an S/M phase-associated lengthening of the parasite’s intraerythrocytic developmental cycle and a reduced merozoite invasion efficiency. The addition of glucosamine partially restored the wild type phenotype. Our study suggests a role of PfUT in controlling cell cycle progression and merozoite invasion. Our study further raises awareness regarding unexpected effects on gene expression when inserting the glms ribozyme sequence into a gene locus.

scholarly journals PfAP2-EXP2, an Essential Transcription Factor for the Intraerythrocytic Development of Plasmodium falciparum

2022 ◽  
Vol 9 ◽  
Author(s):  
Xiaomin Shang ◽  
Changhong Wang ◽  
Li Shen ◽  
Fei Sheng ◽  
Xiaohui He ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Transcription Factor ◽  
Dna Sequences ◽  
Transcriptome Profiling ◽  
Growth Defect ◽  
Developmental Cycle ◽  
Appreciable Effect ◽  
Expression Of Genes ◽  
Cell Remodeling ◽  
New Perspective

Plasmodium falciparum undergoes a series of asexual replications in human erythrocytes after infection, which are effective targets for combatting malaria. Here, we report roles of an ApiAP2 transcription factor PfAP2-EXP2 (PF3D7_0611200) in the intraerythrocytic developmental cycle of P. falciparum. PfAP2-EXP2 conditional knockdown resulted in an asexual growth defect but without an appreciable effect on parasite morphology. Further ChIP-seq analysis revealed that PfAP2-EXP2 targeted genes related to virulence and interaction between erythrocytes and parasites. Especially, PfAP2-EXP2 regulation of euchromatic genes does not depend on recognizing specific DNA sequences, while a CCCTAAACCC motif is found in its heterochromatic binding sites. Combined with transcriptome profiling, we suggest that PfAP2-EXP2 is participated in the intraerythrocytic development by affecting the expression of genes related to cell remodeling at the schizont stage. In summary, this study explores an ApiAP2 member plays an important role for the P. falciparum blood-stage replication, which suggests a new perspective for malaria elimination.

scholarly journals Identification and Disruption of the Gene Encoding the Third Member of the Low-Molecular-Mass Rhoptry Complex in Plasmodium falciparum

2002 ◽  
Vol 70 (9) ◽  
pp. 5236-5245 ◽  
Author(s):  
Deborah L. Baldi ◽  
Robert Good ◽  
Manoj T. Duraisingh ◽  
Brendan S. Crabb ◽  
Alan F. Cowman
Keyword(s):  
Plasmodium Falciparum ◽  
Molecular Mass ◽  
Parasite Species ◽  
Single Gene ◽  
Plasmodium Yoelii ◽  
Gene Encoding ◽  
Genome Database ◽  
Merozoite Invasion ◽  
Homologous Genes ◽  
Genes Encoding

ABSTRACT The low-molecular-mass rhoptry complex of Plasmodium falciparum consists of three proteins, rhoptry-associated protein 1 (RAP1), RAP2, and RAP3. The genes encoding RAP1 and RAP2 are known; however, the RAP3 gene has not been identified. In this study we identify the RAP3 gene from the P. falciparum genome database and show that this protein is part of the low-molecular-mass rhoptry complex. Disruption of RAP3 demonstrated that it is not essential for merozoite invasion, probably because RAP2 can complement the loss of RAP3. RAP3 has homology with RAP2, and the genes are encoded on chromosome 5 in a head-to-tail fashion. Analysis of the genome databases has identified homologous genes in all Plasmodium spp., suggesting that this protein plays a role in merozoite invasion. The region surrounding the RAP3 homologue in the Plasmodium yoelii genome is syntenic with the same region in P. falciparum; however, there is a single gene. Phylogenetic comparison of the RAP2/3 protein family from Plasmodium spp. suggests that the RAP2/3 duplication occurred after divergence of these parasite species.

scholarly journals Primary structure of the 175K Plasmodium falciparum erythrocyte binding antigen and identification of a peptide which elicits antibodies that inhibit malaria merozoite invasion.

1990 ◽  
Vol 111 (5) ◽  
pp. 1877-1884 ◽  
Author(s):  
B K Sim ◽  
P A Orlandi ◽  
J D Haynes ◽  
F W Klotz ◽  
J M Carter ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Amino Acid ◽  
Vaccine Development ◽  
Fluorescent Antibody ◽  
Amino Acid Residues ◽  
Gene Encoding ◽  
Merozoite Invasion ◽  
Reading Frame ◽  
Erythrocyte Binding

The Plasmodium falciparum gene encoding erythrocyte binding antigen-175 (EBA-175), a putative receptor for red cell invasion (Camus, D., and T. J. Hadley. 1985. Science (Wash. DC). 230:553-556.), has been isolated and characterized. DNA sequencing demonstrated a single open reading frame encoding a translation product of 1,435 amino acid residues. Peptides corresponding to regions on the deduced amino acid sequence predicted to be B cell epitopes were assessed for immunogenicity. Immunization of mice and rabbits with EBA-peptide 4, a synthetic peptide encompassing amino acid residues 1,062-1,103, produced antibodies that recognized P. falciparum merozoites in an indirect fluorescent antibody assay. When compared to sera from rabbits immunized with the same adjuvant and carrier protein, sera from rabbits immunized with EBA-peptide 4 inhibited merozoite invasion of erythrocytes in vitro by 80% at a 1:5 dilution. Furthermore, these sera inhibited the binding of purified, authentic EBA-175 to erythrocytes, suggesting that their activity in inhibiting merozoite invasion of erythrocytes is mediated by blocking the binding of EBA-175 to erythrocytes. Since the nucleotide sequence of EBA-peptide 4 is conserved among seven strains of P. falciparum from throughout the world (Sim, B. K. L. 1990. Mol. Biochem. Parasitol. 41:293-296.), these data identify a region of the protein that should be a focus of vaccine development efforts.

scholarly journals Genome-wide regulatory dynamics of translation in the Plasmodium falciparum asexual blood stages

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Florence Caro ◽  
Vida Ahyong ◽  
Miguel Betegon ◽  
Joseph L DeRisi
Keyword(s):  
Plasmodium Falciparum ◽  
Translational Control ◽  
Ribosome Profiling ◽  
Developmental Cycle ◽  
Molecular Physiology ◽  
Protein Levels ◽  
Genome Wide ◽  
Tightly Coupled ◽  
Regulatory Dynamics

The characterization of the transcriptome and proteome of Plasmodium falciparum has been a tremendous resource for the understanding of the molecular physiology of this parasite. However, the translational dynamics that link steady-state mRNA with protein levels are not well understood. In this study, we bridge this disconnect by measuring genome-wide translation using ribosome profiling, through five stages of the P. falciparum blood phase developmental cycle. Our findings show that transcription and translation are tightly coupled, with overt translational control occurring for less than 10% of the transcriptome. Translationally regulated genes are predominantly associated with merozoite egress functions. We systematically define mRNA 5′ leader sequences, and 3′ UTRs, as well as antisense transcripts, along with ribosome occupancy for each, and establish that accumulation of ribosomes on 5′ leaders is a common transcript feature. This work represents the highest resolution and broadest portrait of gene expression and translation to date for this medically important parasite.

scholarly journals CRISPR/Cas9 genome editing system confirms centriolin’s role in cytokinesis

2022 ◽  
Vol 15 (1) ◽  
Author(s):  
Eric Seronick ◽  
Jae Son ◽  
Cameron Michael ◽  
Hannah Fogg ◽  
Zeynep Gromley ◽  
...  
Keyword(s):  
Cell Division ◽  
Genome Editing ◽  
Cell Cycle Progression ◽  
Primary Cilia ◽  
Effective Means ◽  
Mrna Level ◽  
Microtubule Organizing Center ◽  
Gene Encoding ◽  
Protein Levels ◽  
Organizing Center

Abstract Objective In addition to its function as the microtubule organizing center of the cell, the centrosome has functions in many other cellular processes including primary cilia formation, DNA damage checkpoints, and cell cycle progression. But the role of individual components of the centrosome in these processes remains unclear. Previous studies used siRNA (small interfering RNA) to “knock down” protein levels of the centrosome component centriolin, resulting in failed cytokinesis. Since this approach was transient, only targeting centriolin at the mRNA level, we sought to confirm these findings by permanently disrupting the gene encoding centriolin using the CRISPR/Cas9 system of genome editing. Results This study provides evidence that the CRISPR/Cas9 system is capable of effectively reducing centriolin protein levels in the cell. Furthermore, this disruption leads to a failure of cytokinesis that is reminiscent of the phenotype previously reported for the siRNA-mediated disruption of centriolin. Furthermore, no additional defects in cell division were observed, consistent with results seen with previous siRNA studies. We conclude that the CRISPR/Cas9 system is an effective means of permanently removing the cellular pools of centriolin and that the disruption of centriolin at both the mRNA level and genomic level lead to similar cell division defects.

scholarly journals Cinnamon Oil Inhibits Penicillium expansum Growth by Disturbing the Carbohydrate Metabolic Process

2021 ◽  
Vol 7 (2) ◽  
pp. 123
Author(s):  
Tongfei Lai ◽  
Yangying Sun ◽  
Yaoyao Liu ◽  
Ran Li ◽  
Yuanzhi Chen ◽  
...  
Keyword(s):  
Pentose Phosphate ◽  
Metabolic Process ◽  
Penicillium Expansum ◽  
Economic Losses ◽  
Pome Fruit ◽  
Cinnamon Oil ◽  
Atp Production ◽  
Protein Levels ◽  
Regulatory Enzymes ◽  
Expression Of Genes

Penicillium expansum is a major postharvest pathogen that mainly threatens the global pome fruit industry and causes great economic losses annually. In the present study, the antifungal effects and potential mechanism of cinnamon oil against P. expansum were investigated. Results indicated that 0.25 mg L−1 cinnamon oil could efficiently inhibit the spore germination, conidial production, mycelial accumulation, and expansion of P. expansum. In addition, it could effectively control blue mold rots induced by P. expansum in apples. Cinnamon oil could also reduce the expression of genes involved in patulin biosynthesis. Through a proteomic quantitative analysis, a total of 146 differentially expressed proteins (DEPs) involved in the carbohydrate metabolic process, most of which were down-regulated, were noticed for their large number and functional significance. Meanwhile, the expressions of 14 candidate genes corresponding to DEPs and the activities of six key regulatory enzymes (involving in cellulose hydrolyzation, Krebs circle, glycolysis, and pentose phosphate pathway) showed a similar trend in protein levels. In addition, extracellular carbohydrate consumption, intracellular carbohydrate accumulation, and ATP production of P. expansum under cinnamon oil stress were significantly decreased. Basing on the correlated and mutually authenticated results, we speculated that disturbing the fungal carbohydrate metabolic process would be partly responsible for the inhibitory effects of cinnamon oil on P. expansum growth. The findings would provide new insights into the antimicrobial mode of cinnamon oil.

scholarly journals Expression of Apoptosis-Related Genes in Cat Testicular Tissue in Relation to Sperm Morphology and Seasonality—A Preliminary Study

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 489
Author(s):  
Sylwia Prochowska ◽  
Agnieszka Partyka ◽  
Wojciech Niżański
Keyword(s):  
Sperm Morphology ◽  
Semen Quality ◽  
Testicular Tissue ◽  
Reproductive Season ◽  
Tissue Samples ◽  
Protein Levels ◽  
Expression Of Genes ◽  
Testicular Regression ◽  
Preliminary Study ◽  
Apoptotic Genes

Apoptosis is a crucial process in spermatogenesis, responsible for the elimination of abnormal sperm cells and testicular regression out of breeding season. The aim of this study was to assess if the expression of apoptosis-related genes in testicular tissue of domestic cats differed: (1) between normozoospermic and teratozoospermic donors, and (2) between reproductive and non-reproductive season. The expression of genes: BCL2L1, BCL2, BAX, BAD, FAS, FASLG, and caspases (CASP3, CASP8, CASP9, and CASP10) was analyzed by qRT-PCR in testicular tissue samples. During non-reproductive season significantly higher expression of two anti-apoptotic genes (BCL2L1 and BCL2) was observed. Additionally, there was a significant higher expression of CASP10 in teratozoospermic cats during non-reproductive than during reproductive season. No differences were noted between normozoospermic and teratozoospermic groups. Upregulation of some genes during the non-reproductive season indicates engagement of apoptotic mechanisms in the seasonal changes of semen quality in cats, however further studies on protein levels and analysis of changes on distinct testicular germinal layers are required. At the same time, teratozoospermia in the general population of cats seems to be not connected with dysregulation of apoptosis in the testes.

scholarly journals Alopecia in Harlequin mutant mice is associated with reduced AIF protein levels and expression of retroviral elements

2020 ◽  
Author(s):  
Maik Hintze ◽  
Sebastian Griesing ◽  
Marion Michels ◽  
Birgit Blanck ◽  
Lena Wischhof ◽  
...  
Keyword(s):  
Hair Growth ◽  
Transcriptional Regulators ◽  
Mutant Mice ◽  
Wild Type ◽  
Protein Levels ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Keratinocyte Cell ◽  
Apoptosis Inducing Factor ◽  
Hair Cortex

AbstractWe investigated the contribution of apoptosis-inducing factor (AIF), a key regulator of mitochondrial biogenesis, in supporting hair growth. We report that pelage abnormalities developed during hair follicle (HF) morphogenesis in Harlequin (Hq) mutant mice. Fragility of the hair cortex was associated with decreased expression of genes encoding structural hair proteins, though key transcriptional regulators of HF development were expressed at normal levels. Notably, Aifm1 (R200 del) knockin males and Aifm1(R200 del)/Hq females showed minor hair defects, despite substantially reduced AIF levels. Furthermore, we cloned the integrated ecotropic provirus of the Aifm1Hq allele. We found that its overexpression in wild-type keratinocyte cell lines led to down-regulation of HF-specific Krt84 and Krtap3-3 genes without altering Aifm1 or epidermal Krt5 expression. Together, our findings imply that pelage paucity in Hq mutant mice is mechanistically linked to severe AIF deficiency and is associated with the expression of retroviral elements that might potentially influence the transcriptional regulation of structural hair proteins.

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