Genome-wide analysis of transcription factor PfNF-YB in Plasmodium falciparum.
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ABSTRACT: PfNF-YB is a transcription factor of Plasmodium falciparum and is known as a CCAAT-box-binding subunit B. PfNF-YB belongs to NF-Y complex family that is conserved from yeast to human. PfNF-YB is highly expressed in schizont stage and co-localized at the nucleus in mature form during intraerythrocytic stage. We found that melatonin and cAMP second messenger can modulate the PfNF-YB expression in P. falciparum. To better understand the function of PfNF-YB in P. falciparum we proposed to perform chromatin immunoprecipitation (ChIP) of PfNF-YB together with chromatin profiling by ChIP-on-chip analysis. The results showed that PfNF-YB binds to CCAAT of several genes in schizont stage.
Project description:PfNF-YB transcription factor is highly expressed and co-localized at the nucleuos in mature form during intra-erytrocytic stages. melatonin and cAMP second messenger can modulate the PfNF-YB expression in P. falciparum erythrocyte stages. Chromatin immunoprecipitation (ChIP) of PfNF-YB together with chromatin profiling by ChIP-on-chip analysis demonstrated that PfNF-YB binding to CCAAT of several genes in schizont stage. comparison of PfNF-YB vs control beads and IgG
Project description:The rate of mRNA decay is an essential element of post-transcriptional regulation in all organisms. Previously, studies in several organisms found that the specific half-life of each mRNA is precisely related to its physiological role, and plays an important role in determining levels of gene expression. We have used a genome wide approach to characterize mRNA decay in Plasmodium falciparum. We found that globally, rates of mRNA decay increase dramatically during the asexual intraerythrocytic developmental cycle. During the ring stage of the cycle, the average mRNA half-life was 9.5 minutes, yet this was extended to an average of 65 minutes during the late schizont stage of development. Thus a major determinant of mRNA decay rate appears to be linked to the stage of intraerythrocytic development. Furthermore, we have found specific variations in decay patterns superimposed upon the dominant trend of progressive half-life lengthening. These variations in decay pattern were frequently enriched for genes with specific cellular functions or processes. Elucidation of Plasmodium mRNA decay rates provides a key element for deciphering mechanisms of genetic control in this parasite, by complementing and extending previous mRNA abundance studies. Our results indicate that progressive stage-dependent decreases in mRNA decay rate function are a major determinant of mRNA accumulation during the schizont stage of intraerythrocytic development. This type of genome wide change in mRNA decay rate has not been observed in any other organism to date, and indicates that post-transcriptional regulation may be the dominant mechanism of gene regulation in P. falciparum. Keywords: Plasmodium falciparum treated with actinomycin D
Project description:We identified unconventional histone lysine trimethylation mark in the nucleosome core at H3K64 position in human malaria parasite Plasmodium falciparum. Global ChIP analysis was performed using anti-H3K64me3 specific antibody for three major blood stages, i.e. ring, trophozoite and schizont stages to identify the genomic position of the H3K64me3. The sheared chromatin was prepared from highly synchronous P. falciparum culture and subjected for ChIP followed by library preparation from the ChIP DNA and were subjected to sequencing using the HiSeq Illumina platform. H3K64me3 binding sites were determined after sequence alignment and normalization with input sequence. Interestingly, there was a significant reduction in the number of peaks on different chromosomes during multinucleated schizont stage as compared to ring and trophozoite stage. Collectively, this is first study to show that H3K64me3 function as repressor methyl mark during ring and trophozoite stages to regulate the expression of schizont specific export family of proteins in P. falciparum.
Project description:Comparison of expression profile of two 3D7 isogenic clones : 3D7AH1S2 and 3D7S8.4 at three different stages of intraerythrocytic cycle: ring, trophozite and schizont stage
Project description:We present results of RNA-Seq, Ribo-Seq, and RIP-Seq (YB-1, YB-3) experiments performed in HEK293T cells, as well as in HEK293T cells with YB-1 knockout and overexpression. The data shows YB-1 function as a global translation inhibitor and YB-3 ability to substitute YB-1 in its function in YB-1 knockout mutant.
Project description:Nuclear Factor Y (NF-Y) is a heterotrimeric transcription factor that binds CCAAT elements. The NF-Y trimer is composed of a Histone Fold Domain (HFD) dimer (NF-YB/NF-YC) and NF-YA, which confers DNA sequence specificity. NF-YA shares a conserved domain with the CONSTANS, CONSTANS-LIKE, TOC1 (CCT) proteins. We show that CONSTANS (CO/B-BOX PROTEIN1 BBX1), a master flowering regulator, forms a trimer with Arabidopsis thaliana NF-YB2/NF-YC3 to efficiently bind the CORE element of the FLOWERING LOCUS T promoter. Using saturation mutagenesis, electrophoretic mobility shift assays, and RNA-sequencing profiling of co, nf-yb, and nf-yc mutants, we identify CCACA elements as the core NF-CO binding site. CO physically interacts with the same HFD surface required for NF-YA association, as determined by mutations in NF-YB2 and NF-YC9, and tested in vitro and in vivo. The co-7 mutation in the CCT domain, corresponding to an NF-YA arginine directly involved in CCAAT recognition, abolishes NF-CO binding to DNA
Project description:Genome-wide ChIP-sequencing analysis of PfGCN5 was carried out in asynchronous stage (trophozoite and schizont stage enriched) parasites using PfGCN5 antibodies. We have observed that PfGCN5 is majorly associated with promoter regions of genes. Moreover, a uniform distribution was found in exons, transcription termination site, and intergenic regions. This study shed some light on PfGCN5 binding sites on Plasmodium falciparum genome.
Project description:In this study, we generated transcriptome profiles from HEK293T, HEK293T ΔYB-1ΔYB-3, and HEK293T ΔYB-1ΔYB-3 with the restored expression of YB-1 and/or YB-3. The data are used to explore YB-1 and YB-3 influence on transcriptome and translatome and their functional interchangeability in transcription and translation.
Project description:Plasmodium falciparum intraerythrocytic stage transcription four hour time course for NF54 and PB58 (an isogenic line with a piggyBac transposon in the promotor of K13 that alters K13 expression)
Project description:Transient regulation of Plasmodium numbers below the density that induces fever has been observed in chronic malaria infections in humans and this species transcending control cannot be explained by immunity alone. Using an in vitro system we have observed density dependent regulation of malaria parasitemia as a mechanism to possibly explain these in vivo observations. P. falciparum blood stages from a high but not low-density environment exhibited what appeared to be programmed changes during the late trophozoite and schizont stages of the intraerythrocytic cycle.