scholarly journals From Genes to Transcripts, a Tightly Regulated Journey in Plasmodium

2020 ◽  
Vol 10 ◽  
Author(s):  
Thomas Hollin ◽  
Karine G. Le Roch
Keyword(s):  
Life Cycle ◽  
Malaria Parasite ◽  
Molecular Mechanisms ◽  
Cell Types ◽  
Regulatory Mechanisms ◽  
Tight Control ◽  
Control Of Gene Expression ◽  
Human Malaria Parasite ◽  
Stage Conversion ◽  
The Past

Over the past decade, we have witnessed significant progresses in understanding gene regulation in Apicomplexa including the human malaria parasite, Plasmodium falciparum. This parasite possesses the ability to convert in multiple stages in various hosts, cell types, and environments. Recent findings indicate that P. falciparum is talented at using efficient and complementary molecular mechanisms to ensure a tight control of gene expression at each stage of its life cycle. Here, we review the current understanding on the contribution of the epigenome, atypical transcription factors, and chromatin organization to regulate stage conversion in P. falciparum. The adjustment of these regulatory mechanisms occurring during the progression of the life cycle will be extensively discussed.

scholarly journals Identification, Characterization, and Regulatory Mechanisms of a Novel EGR1 Splicing Isoform

2019 ◽  
Vol 20 (7) ◽  
pp. 1548 ◽  
Author(s):  
Vincenza Aliperti ◽  
Giulia Sgueglia ◽  
Francesco Aniello ◽  
Emilia Vitale ◽  
Laura Fucci ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Cell Types ◽  
Regulatory Mechanisms ◽  
Brain Diseases ◽  
Regulation Of Transcription ◽  
Biological Processes ◽  
Activation Domain ◽  
Post Translational Modifications ◽  
Pathological Conditions ◽  
Proliferation And Apoptosis

EGR1 is a transcription factor expressed in many cell types that regulates genes involved in different biological processes including growth, proliferation, and apoptosis. Dysregulation of EGR1 expression has been associated with many pathological conditions such as tumors and brain diseases. Known molecular mechanisms underlying the control of EGR1 function include regulation of transcription, mRNA and protein stability, and post-translational modifications. Here we describe the identification of a splicing isoform for the human EGR1 gene. The newly identified splicing transcript encodes a shorter protein compared to the canonical EGR1. This isoform lacks a region belonging to the N-terminal activation domain and although it is capable of entering the nucleus, it is unable to activate transcription fully relative to the canonical isoform.

scholarly journals Gating and Regulatory Mechanisms of TMEM16 Ion Channels and Scramblases

2021 ◽  
Vol 12 ◽  
Author(s):  
Son C. Le ◽  
Pengfei Liang ◽  
Augustus J. Lowry ◽  
Huanghe Yang
Keyword(s):  
Ion Channels ◽  
Molecular Mechanisms ◽  
Transmembrane Protein ◽  
Structural Features ◽  
Regulatory Mechanisms ◽  
Membrane Bilayer ◽  
Flip Flop ◽  
The Past ◽  
Activation Gating ◽  
Health And Disease

The transmembrane protein 16 (TMEM16) family consists of Ca2+-activated ion channels and Ca2+-activated phospholipid scramblases (CaPLSases) that passively flip-flop phospholipids between the two leaflets of the membrane bilayer. Owing to their diverse functions, TMEM16 proteins have been implicated in various human diseases, including asthma, cancer, bleeding disorders, muscular dystrophy, arthritis, epilepsy, dystonia, ataxia, and viral infection. To understand TMEM16 proteins in health and disease, it is critical to decipher their molecular mechanisms of activation gating and regulation. Structural, biophysical, and computational characterizations over the past decade have greatly advanced the molecular understanding of TMEM16 proteins. In this review, we summarize major structural features of the TMEM16 proteins with a focus on regulatory mechanisms and gating.

scholarly journals MicroRNAs: Recent insights towards their role in male infertility and reproductive cancers

2019 ◽  
Vol 19 (1) ◽  
pp. 31-42 ◽  
Author(s):  
Muhammad Babar Khawar ◽  
Rabia Mehmood ◽  
Nabila Roohi
Keyword(s):  
Male Infertility ◽  
Reproductive System ◽  
Molecular Mechanisms ◽  
Cell Types ◽  
Regulatory Mechanisms ◽  
Aberrant Expression ◽  
Protein Coding ◽  
Reproductive Cancers ◽  
Post Transcriptional Regulation ◽  
Different Cell Types

Spermatogenesis is a tightly controlled, multi-step process in which mature spermatozoa are produced. Disruption of regulatory mechanisms in spermatogenesis can lead to male infertility, various diseases of male reproductive system, or even cancer. The spermatogenic impairment in infertile men can be associated with different etiologies, and the exact molecular mechanisms are yet to be determined. MicroRNAs (miRNAs) are a type of non-protein coding RNAs, about 22 nucleotides long, with an essential role in post-transcriptional regulation. miRNAs have been recognized as important regulators of various biological processes, including spermatogenesis. The aim of this review is to summarize the recent literature on the role of miRNAs in spermatogenesis, male infertility and reproductive cancers, and to evaluate their potential in diagnosis, prognosis and therapy of disease. Experimental evidence shows that aberrant expression of miRNAs affects spermatogenesis at multiple stages and in different cell types, most often resulting in infertility. In more severe cases, dysregulation of miRNAs leads to cancer. miRNAs have enormous potential to be used as diagnostic and prognostic markers as well as therapeutic targets in male infertility and reproductive system diseases. However, to exploit this potential fully, we need a better understanding of miRNA-mediated regulation of spermatogenesis, including the characterization of yet unidentified miRNAs and related regulatory mechanisms.

scholarly journals Hematopoietic cytokines

Blood ◽  
2008 ◽  
Vol 111 (2) ◽  
pp. 485-491 ◽  
Author(s):  
Donald Metcalf
Keyword(s):  
Hematopoietic Cells ◽  
Cell Types ◽  
Lymphoid Cells ◽  
Simultaneous Action ◽  
Colony Stimulating Factor ◽  
Tight Control ◽  
The Past ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor

The production of hematopoietic cells is under the tight control of a group of hematopoietic cytokines. Each cytokine has multiple actions mediated by receptors whose cytoplasmic domains contain specialized regions initiating the various responses—survival, proliferation, differentiation commitment, maturation, and functional activation. Individual cytokines can be lineage specific or can regulate cells in multiple lineages, and for some cell types, such as stem cells or megakaryocyte progenitors, the simultaneous action of multiple cytokines is required for proliferative responses. The same cytokines control basal and emergency hematopoietic cell proliferation. Three cytokines, erythropoietin, granulocyte colony-stimulating factor, and granulocyte-macrophage colony-stimulating factor, have now been in routine clinical use to stimulate cell production and in total have been used in the management of many millions of patients. In this little review, discussion will be restricted to those cytokines well established as influencing the production of hematopoietic cells and will exclude newer candidate regulators and those active on lymphoid cells. As requested, this account will describe the cytokines in a historical manner, using a sequential format of discovery, understanding, validation, and puzzlement, a sequence that reflects the evolving views on these cytokines over the past 50 years.

scholarly journals The Molecular Interplay between Human Coronaviruses and Autophagy

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 2022
Author(s):  
Ankit Shroff ◽  
Taras Y. Nazarko
Keyword(s):  
Life Cycle ◽  
Membrane Trafficking ◽  
Molecular Mechanisms ◽  
Membrane Vesicles ◽  
Intracellular Protein ◽  
Double Membrane ◽  
The Past ◽  
Trafficking Pathway ◽  
Life Threatening ◽  
Human Coronaviruses

Coronavirus disease 2019 (COVID-19), caused by a new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has instantaneously emerged as a worldwide pandemic. However, humans encountered other coronaviruses in the past, and they caused a broad range of symptoms, from mild to life-threatening, depending on the virus and immunocompetence of the host. Most human coronaviruses interact with the proteins and/or double-membrane vesicles of autophagy, the membrane trafficking pathway that degrades and recycles the intracellular protein aggregates, organelles, and pathogens, including viruses. However, coronaviruses often neutralize and hijack this pathway to complete their life cycle. In this review, we discuss the interactions of human coronaviruses and autophagy, including recent data from SARS-CoV-2-related studies. Some of these interactions (for example, viral block of the autophagosome–lysosome fusion), while being conserved across multiple coronaviruses, are accomplished via different molecular mechanisms. Therefore, it is important to understand the molecular interplay between human coronaviruses and autophagy for developing efficient therapies against coronaviral diseases.

scholarly journals Do Epigenetic Timers Control Petal Development?

2021 ◽  
Vol 12 ◽  
Author(s):  
Ruirui Huang ◽  
Tengbo Huang ◽  
Vivian F. Irish
Keyword(s):  
Gene Expression ◽  
Molecular Mechanisms ◽  
Environmental Changes ◽  
Cell Types ◽  
Epigenetic Factors ◽  
Control Of Gene Expression ◽  
Dna Accessibility ◽  
Developmental Progression ◽  
Petal Development ◽  
Incomplete Picture

Epigenetic modifications include histone modifications and DNA methylation; such modifications can induce heritable changes in gene expression by altering DNA accessibility and chromatin structure. A number of studies have demonstrated that epigenetic factors regulate plant developmental timing in response to environmental changes. However, we still have an incomplete picture of how epigenetic factors can regulate developmental events such as organogenesis. The small number of cell types and the relatively simple developmental progression required to form the Arabidopsis petal makes it a good model to investigate the molecular mechanisms driving plant organogenesis. In this minireview, we summarize recent studies demonstrating the epigenetic control of gene expression during various developmental transitions, and how such regulatory mechanisms can potentially act in petal growth and differentiation.

PolyQ-mediated regulation of mRNA granules assembly

2014 ◽  
Vol 42 (4) ◽  
pp. 1246-1250 ◽  
Author(s):  
Virginia Castilla-Llorente ◽  
Andres Ramos
Keyword(s):  
Life Cycle ◽  
Molecular Mechanisms ◽  
Cell Types ◽  
Rna Granules ◽  
Sequence Complexity ◽  
Pathological Conditions ◽  
Computational Data ◽  
Mrna Granules

RNA granules have been observed in different organisms, cell types and under different conditions, and their formation is crucial for the mRNA life cycle. However, very little is known about the molecular mechanisms governing their assembly and disassembly. The aggregation-prone LSCRs (low-sequence-complexity regions), and in particular, the polyQ/N-rich regions, have been extensively studied under pathological conditions due to their role in neurodegenerative diseases. In the present review, we discuss recent in vitro, in vivo and computational data that, globally, suggest a role for polyQ/N regions in RNA granule assembly.

scholarly journals Malaria parasite egress at a glance

2021 ◽  
Vol 134 (5) ◽  
pp. jcs257345
Author(s):  
Michele S. Y Tan ◽  
Michael J. Blackman
Keyword(s):  
Life Cycle ◽  
Malaria Control ◽  
Cyst Wall ◽  
Malaria Parasite ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Complex Life Cycle ◽  
Intracellular Pathogens ◽  
Parasite Egress ◽  
Intracellular Vacuole

ABSTRACTAll intracellular pathogens must escape (egress) from the confines of their host cell to disseminate and proliferate. The malaria parasite only replicates in an intracellular vacuole or in a cyst, and must undergo egress at four distinct phases during its complex life cycle, each time disrupting, in a highly regulated manner, the membranes or cyst wall that entrap the parasites. This Cell Science at a Glance article and accompanying poster summarises our current knowledge of the morphological features of egress across the Plasmodium life cycle, the molecular mechanisms that govern the process, and how researchers are working to exploit this knowledge to develop much-needed new approaches to malaria control.

scholarly journals Ontogeny reversal and phylogenetic analysis of Turritopsis sp.5 (Cnidaria, Hydrozoa, Oceaniidae), a possible new species endemic to Xiamen, China

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4225 ◽  
Author(s):  
Jun-yuan Li ◽  
Dong-hui Guo ◽  
Peng-cheng Wu ◽  
Li-sheng He
Keyword(s):  
Phylogenetic Analysis ◽  
Life Cycle ◽  
Molecular Mechanisms ◽  
Morphological Changes ◽  
Cell Types ◽  
Japanese Species ◽  
Ordinary Life ◽  
Polyp Stage ◽  
First Time ◽  
Contraction Stage

Ontogeny reversal, as seen in some cnidarians, is an unprecedented phenomenon in the animal kingdom involving reversal of the ordinary life cycle. Three species of Turritopsis have been shown to be capable of inverted metamorphosis, a process in which the pelagic medusa transforms back into a juvenile benthic polyp stage when faced with adverse conditions. Turritopsis sp.5 is a species of Turritopsis collected from Xiamen, China which presents a similar ability, being able to reverse its life cycle if injured by mechanical stress. Phylogenetic analysis based on both 16S rDNA and cytochrome c oxidase subunit I (COI) genetic barcodes shows that Turritopsis sp.5 is phylogenetically clustered in a clade separate from other species of Turritopsis. The genetic distance between T. sp.5 and the Japanese species T. sp.2 is the shortest, when measured by the Kimura 2-Parameter metric, and the distance to the New Zealand species T. rubra is the largest. An experimental assay on the induction of reverse development in this species was initiated by cutting medusae into upper and lower parts. We show, for the first time, that the two dissected parts have significantly different potentials to transform into polyps. Also, a series of morphological changes of the reversed life cycle can be recognised, including medusa stage, contraction stage I, contraction stage II, cyst, cyst with stolons, and polyp. The discovery of species capable of reverse ontogeny caused by unfavorable conditions adds to the available systems with which to study the cell types that contribute to the developmental reversal and the molecular mechanisms of the directional determination of ontogeny.

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