Control of gene expression inXenopus early development

1998 ◽  
Vol 22 (2) ◽  
pp. 122-131 ◽  
Author(s):  
Alan Hair ◽  
Marie-Noëlle Prioleau ◽  
Yegor Vassetzky ◽  
Marcel Méchali
2021 ◽  
Author(s):  
Thao Nguyen ◽  
Eli Costa ◽  
Tim Deibert ◽  
Jose Reyes ◽  
Felix Keber ◽  
...  

The development of a fertilized egg to an embryo requires the proper temporal control of gene expression. During cell differentiation, timing is often controlled via cascades of transcription factors (TFs). However, in early development, transcription is often inactive, and many TF levels are constant, suggesting that unknown mechanisms govern the observed rapid and ordered onset of gene expression. Here, we find that in early embryonic development, access of maternally deposited nuclear proteins to the genome is temporally ordered via importin affinities, thereby timing the expression of downstream targets. We quantify changes in the nuclear proteome during early development and find that nuclear proteins, such as TFs and RNA polymerases, enter nuclei sequentially. Moreover, we find that the timing of the access of nuclear proteins to the genome corresponds to the timing of downstream gene activation. We show that the affinity of proteins to importin is a major determinant in the timing of protein entry into embryonic nuclei. Thus, we propose a mechanism by which embryos encode the timing of gene expression in early development via biochemical affinities. This process could be critical for embryos to organize themselves before deploying the regulatory cascades that control cell identities.


2019 ◽  
Vol 15 (2) ◽  
pp. 120-130
Author(s):  
Mohammad Ghanbari ◽  
Reza Safaralizadeh ◽  
Kiyanoush Mohammadi

At the present time, cancer is one of the most lethal diseases worldwide. There are various factors involved in the development of cancer, including genetic factors, lifestyle, nutrition, and so on. Recent studies have shown that epigenetic factors have a critical role in the initiation and development of tumors. The histone post-translational modifications (PTMs) such as acetylation, methylation, phosphorylation, and other PTMs are important mechanisms that regulate the status of chromatin structure and this regulation leads to the control of gene expression. The histone acetylation is conducted by histone acetyltransferase enzymes (HATs), which are involved in transferring an acetyl group to conserved lysine amino acids of histones and consequently increase gene expression. On the basis of similarity in catalytic domains of HATs, these enzymes are divided into different groups such as families of GNAT, MYST, P300/CBP, SRC/P160, and so on. These enzymes have effective roles in apoptosis, signaling pathways, metastasis, cell cycle, DNA repair and other related mechanisms deregulated in cancer. Abnormal activation of HATs leads to uncontrolled amplification of cells and incidence of malignancy signs. This indicates that HAT might be an important target for effective cancer treatments, and hence there would be a need for further studies and designing of therapeutic drugs on this basis. In this study, we have reviewed the important roles of HATs in different human malignancies.


2021 ◽  
Vol 4 (1) ◽  
pp. 22
Author(s):  
Mrinmoyee Majumder ◽  
Viswanathan Palanisamy

Control of gene expression is critical in shaping the pro-and eukaryotic organisms’ genotype and phenotype. The gene expression regulatory pathways solely rely on protein–protein and protein–nucleic acid interactions, which determine the fate of the nucleic acids. RNA–protein interactions play a significant role in co- and post-transcriptional regulation to control gene expression. RNA-binding proteins (RBPs) are a diverse group of macromolecules that bind to RNA and play an essential role in RNA biology by regulating pre-mRNA processing, maturation, nuclear transport, stability, and translation. Hence, the studies aimed at investigating RNA–protein interactions are essential to advance our knowledge in gene expression patterns associated with health and disease. Here we discuss the long-established and current technologies that are widely used to study RNA–protein interactions in vivo. We also present the advantages and disadvantages of each method discussed in the review.


Cancers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 350
Author(s):  
Julianty Frost ◽  
Mark Frost ◽  
Michael Batie ◽  
Hao Jiang ◽  
Sonia Rocha

Hypoxia—reduction in oxygen availability—plays key roles in both physiological and pathological processes. Given the importance of oxygen for cell and organism viability, mechanisms to sense and respond to hypoxia are in place. A variety of enzymes utilise molecular oxygen, but of particular importance to oxygen sensing are the 2-oxoglutarate (2-OG) dependent dioxygenases (2-OGDs). Of these, Prolyl-hydroxylases have long been recognised to control the levels and function of Hypoxia Inducible Factor (HIF), a master transcriptional regulator in hypoxia, via their hydroxylase activity. However, recent studies are revealing that dioxygenases are involved in almost all aspects of gene regulation, including chromatin organisation, transcription and translation. We highlight the relevance of HIF and 2-OGDs in the control of gene expression in response to hypoxia and their relevance to human biology and health.


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