scholarly journals Spatial transcriptomics: Gene expression in space, time and numbers

2021 ◽  
Vol 12 (11) ◽  
pp. 1-2
Author(s):  
Ruby Dhar ◽  
Arun Kumar ◽  
Subhradip Karmakar
Keyword(s):  
Gene Expression ◽  
Messenger Rna ◽  
Cdna Libraries ◽  
Full Potential ◽  
Average Output ◽  
Complex Processes ◽  
Eukaryotic Gene ◽  
Innovative Solution ◽  
Long Time ◽  
Number Of Publications

Eukaryotic gene expression is an array of complex processes that must fine-tune with cellular needs to maintain homeostasis, yet flexible enough to respond to external cues and signals. Transcriptomics is the average output of cellular gene expression wherein messenger RNA copy the information inscribed in the DNA to instruct protein synthesis by the cellular ribosomes in the cytoplasm. So far, the knowledge gained from the transcriptomic-based studies was similar to the Heisenberg uncertainty dilemma. Information about these transcripts could be quantitated with utmost accuracy at the cost of losing information about their cellular spatial coordinates. In other words, we may quantitate the transcripts by PCR or the modern-day next-generation sequencing but cannot comment on where these transcripts originated or are located in the cells/tissues. Suppose we, however, accurately try to localize these transcripts using in-situ hybridization-like techniques; in that case, we are uncertain about its actual copy numbers due to the semi-quantitative nature of these methods. Its genuinely a Heisenbergian tradeoff that baffled the biologist for a long time until now; an innovative solution seems to be in place. Spatial transcriptomics (ST) is the perfect marriage between localization and quantitation without compromising either. It is a method that allows simultaneous visualization and quantitative analysis of the transcriptome by performing histological sections on glass slides incubated with oligonucleotides containing positional barcodes to generate high-quality cDNA libraries, which may be used for quantitation by RNA-sequencing. Increasingly, the scientific community seems to realize this technology’s full potential, as evidenced by the sheer number of publications in the past 2 years. This technology is the first of its kind to provide an unbiased whole transcriptome analysis with anatomical information from tissue sections where these transcripts are expressed. A time laspse serial longitudinal ST is powerful to identify the temporal transcript oscillations and decay at unprecedented accuracy. Cells of different types are spatially and structurally organized within the tissue matrix to perform their complex functions. Uncovering the complex spatial architecture of heterogenous tissue is crucial for our understanding of the disease’s pathology. Understanding the disease is the primary step towards its remedy, and ST is a powerful tool to address this with precision.

scholarly journals Activation of Prp28 ATPase by phosphorylated Npl3 at a critical step of spliceosome remodeling

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Fu-Lung Yeh ◽  
Shang-Lin Chang ◽  
Golam Rizvee Ahmed ◽  
Hsin-I Liu ◽  
Luh Tung ◽  
...  
Keyword(s):  
Gene Expression ◽  
Atpase Activity ◽  
Conformational Changes ◽  
Active Site ◽  
Messenger Rna ◽  
Dead Box ◽  
Eukaryotic Gene Expression ◽  
U1 Snrnp ◽  
Eukaryotic Gene ◽  
Snrnp Protein

AbstractSplicing, a key step in the eukaryotic gene-expression pathway, converts precursor messenger RNA (pre-mRNA) into mRNA by excising introns and ligating exons. This task is accomplished by the spliceosome, a macromolecular machine that must undergo sequential conformational changes to establish its active site. Each of these major changes requires a dedicated DExD/H-box ATPase, but how these enzymes are activated remain obscure. Here we show that Prp28, a yeast DEAD-box ATPase, transiently interacts with the conserved 5′ splice-site (5′SS) GU dinucleotide and makes splicing-dependent contacts with the U1 snRNP protein U1C, and U4/U6.U5 tri-snRNP proteins, Prp8, Brr2, and Snu114. We further show that Prp28’s ATPase activity is potentiated by the phosphorylated Npl3, but not the unphosphorylated Npl3, thus suggesting a strategy for regulating DExD/H-box ATPases. We propose that Npl3 is a functional counterpart of the metazoan-specific Prp28 N-terminal region, which can be phosphorylated and serves as an anchor to human spliceosome.

Role of small nuclear RNAs in eukaryotic gene expression

2013 ◽  
Vol 54 ◽  
pp. 79-90 ◽  
Author(s):  
Saba Valadkhan ◽  
Lalith S. Gunawardane
Keyword(s):  
Gene Expression ◽  
Protein Interactions ◽  
Rna Stability ◽  
Splice Sites ◽  
Branch Site ◽  
Small Nuclear Rnas ◽  
Eukaryotic Gene Expression ◽  
Eukaryotic Gene ◽  
Rna Biogenesis

Eukaryotic cells contain small, highly abundant, nuclear-localized non-coding RNAs [snRNAs (small nuclear RNAs)] which play important roles in splicing of introns from primary genomic transcripts. Through a combination of RNA–RNA and RNA–protein interactions, two of the snRNPs, U1 and U2, recognize the splice sites and the branch site of introns. A complex remodelling of RNA–RNA and protein-based interactions follows, resulting in the assembly of catalytically competent spliceosomes, in which the snRNAs and their bound proteins play central roles. This process involves formation of extensive base-pairing interactions between U2 and U6, U6 and the 5′ splice site, and U5 and the exonic sequences immediately adjacent to the 5′ and 3′ splice sites. Thus RNA–RNA interactions involving U2, U5 and U6 help position the reacting groups of the first and second steps of splicing. In addition, U6 is also thought to participate in formation of the spliceosomal active site. Furthermore, emerging evidence suggests additional roles for snRNAs in regulation of various aspects of RNA biogenesis, from transcription to polyadenylation and RNA stability. These snRNP-mediated regulatory roles probably serve to ensure the co-ordination of the different processes involved in biogenesis of RNAs and point to the central importance of snRNAs in eukaryotic gene expression.

scholarly journals The crucial roles of N6-methyladenosine (m6A) modification in the carcinogenesis and progression of colorectal cancer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhihao Fang ◽  
Yiqiu Hu ◽  
Jinhui Hu ◽  
Yanqin Huang ◽  
Shu Zheng ◽  
...  
Keyword(s):  
Gene Expression ◽  
Colorectal Cancer ◽  
Nuclear Export ◽  
Messenger Rna ◽  
Regulatory Proteins ◽  
Biological Processes ◽  
The Past ◽  
Common Cancer ◽  
Potential Applications ◽  
Regulated Gene Expression

AbstractAs the predominant modification in RNA, N6-methyladenosine (m6A) has attracted increasing attention in the past few years since it plays vital roles in many biological processes. This chemical modification is dynamic, reversible and regulated by several methyltransferases, demethylases and proteins that recognize m6A modification. M6A modification exists in messenger RNA and affects their splicing, nuclear export, stability, decay, and translation, thereby modulating gene expression. Besides, the existence of m6A in noncoding RNAs (ncRNAs) could also directly or indirectly regulated gene expression. Colorectal cancer (CRC) is a common cancer around the world and of high mortality. Increasing evidence have shown that the changes of m6A level and the dysregulation of m6A regulatory proteins have been implicated in CRC carcinogenesis and progression. However, the underlying regulation laws of m6A modification to CRC remain elusive and better understanding of these mechanisms will benefit the diagnosis and therapy. In the present review, the latest studies about the dysregulation of m6A and its regulators in CRC have been summarized. We will focus on the crucial roles of m6A modification in the carcinogenesis and development of CRC. Moreover, we will also discuss the potential applications of m6A modification in CRC diagnosis and therapeutics.

scholarly journals Mammalian GW220/TNGW1 is essential for the formation of GW/P bodies containing miRISC

2012 ◽  
Vol 198 (4) ◽  
pp. 529-544 ◽  
Author(s):  
Virginia Castilla-Llorente ◽  
Lee Spraggon ◽  
Miwako Okamura ◽  
Saif Naseeruddin ◽  
Matthew Adamow ◽  
...  
Keyword(s):  
Gene Expression ◽  
Messenger Rna ◽  
Cellular Localization ◽  
Translational Repression ◽  
P Bodies ◽  
Target Mrna ◽  
Core Components ◽  
Mirna Pathway

The microRNA (miRNA)-induced silencing complex (miRISC) controls gene expression by a posttranscriptional mechanism involving translational repression and/or promoting messenger RNA (mRNA) deadenylation and degradation. The GW182/TNRC6 (GW) family proteins are core components of the miRISC and are essential for miRNA function. We show that mammalian GW proteins have distinctive functions in the miRNA pathway, with GW220/TNGW1 being essential for the formation of GW/P bodies containing the miRISC. miRISC aggregation and formation of GW/P bodies sequestered and stabilized translationally repressed target mRNA. Depletion of GW220 led to the loss of GW/P bodies and destabilization of miRNA-targeted mRNA. These findings support a model in which the cellular localization of the miRISC regulates the fate of the target mRNA.

Light-Induced Gene Expression Using Messenger RNA Molecules

2010 ◽  
Vol 20 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Sigurd Bøe ◽  
Stein Sæbøe-Larssen ◽  
Eivind Hovig
Keyword(s):  
Gene Expression ◽  
Messenger Rna ◽  
Rna Molecules

scholarly journals Differential Effects of Gonadotropin-Releasing Hormone (GnRH) Pulse Frequency on Gonadotropin Subunit and GnRH Receptor Messenger Ribonucleic Acid Levels in Vitro*

Endocrinology ◽  
1997 ◽  
Vol 138 (3) ◽  
pp. 1224-1231 ◽  
Author(s):  
Ursula B. Kaiser ◽  
Andrzej Jakubowiak ◽  
Anna Steinberger ◽  
William W. Chin
Keyword(s):  
Gene Expression ◽  
Messenger Rna ◽  
Pulse Frequency ◽  
Gnrh Receptor ◽  
Pituitary Cells ◽  
Mrna Levels ◽  
Subunit Gene ◽  
Differential Effects ◽  
Messenger Ribonucleic Acid

Abstract The hypothalamic hormone, GnRH, is released and transported to the anterior pituitary in a pulsatile manner, where it binds to specific high-affinity receptors and regulates gonadotropin biosynthesis and secretion. The frequency of GnRH pulses changes under various physiological conditions, and varying GnRH pulse frequencies have been shown to regulate differentially the secretion of LH and FSH and the expression of the gonadotropin α, LHβ, and FSHβ subunit genes in vivo. We demonstrate differential effects of varying GnRH pulse frequency in vitro in superfused primary monolayer cultures of rat pituitary cells. Cells were treated with 10 nm GnRH pulses for 24 h at a frequency of every 0.5, 1, 2, or 4 h. α, LHβ, and FSHβ messenger RNA (mRNA) levels were increased by GnRH at all pulse frequencies. α and LHβ mRNA levels and LH secretion were stimulated to the greatest extent at a GnRH pulse frequency of every 30 min, whereas FSHβ mRNA levels and FSH secretion were stimulated maximally at a lower GnRH pulse frequency, every 2 h. GnRH receptor (GnRHR) mRNA levels also were increased by GnRH at all pulse frequencies and were stimulated maximally at a GnRH pulse frequency of every 30 min. Similar results were obtained when the dose of each pulse of GnRH was adjusted to maintain a constant total cumulative dose of GnRH over 24 h. These data show that gonadotropin subunit gene expression is regulated differentially by varying GnRH pulse frequencies in vitro, suggesting that the differential effects of varying GnRH pulse frequencies on gonadotropin subunit gene expression occur directly at the level of the pituitary. The pattern of regulation of GnRHR mRNA levels correlated with that of α and LHβ but was different from that of FSHβ. This suggests that α and LHβ mRNA levels are maximally stimulated when GnRHR levels are relatively high, whereas FSHβ mRNA levels are maximally stimulated at lower levels of GnRHR expression, and that the mechanism for differential regulation of the gonadotropins by varying pulse frequencies of GnRH may involve levels of GnRHR. Furthermore, these data suggest that the mechanisms whereby varying GnRH pulse frequencies stimulate α, LHβ, and GnRHR gene expression are similar, whereas the stimulation of FSHβ mRNA levels may be different.

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