scholarly journals Molecular determinants that govern scaRNA processing by Drosha/DGCR8

Biology Open ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. bio054619
Author(s):  
Douglas M. McLaurin ◽  
Madelyn K. Logan ◽  
Katheryn E. Lett ◽  
Michael D. Hebert
Keyword(s):  
Cajal Body ◽  
Efficient Production ◽  
New Class ◽  
Molecular Determinants ◽  
Different Types ◽  
Microprocessor Complex ◽  
Sequence Elements ◽  
Rna Fragments

ABSTRACTThe Cajal body (CB) is a subnuclear domain that participates in the biogenesis of many different types of ribonucleoproteins (RNPs), including small nuclear RNPs (snRNPs), small Cajal body-specific RNPs (scaRNPs) and telomerase. Most scaRNAs, the RNA component of scaRNPs, accumulate in CBs. However, there are three scaRNAs (scaRNA 2, 9, and 17) that are known to be processed into small, nucleolar-enriched fragments. Evidence suggests that these fragments are packaged into a new class of RNPs, called regulatory RNPs (regRNPs), and may modify small nucleolar RNP (snoRNP) activity, thus playing a role in rRNA modification. However, the mechanism by which these fragments are produced is unknown. Previous work has reported the involvement of Drosha and DGCR8 in the cleavage of primary-scaRNA9. Here, we expand on that knowledge by identifying sequence elements necessary for the efficient production of these RNA fragments and demonstrate that primary scaRNA 2 and 17 are also processed by the Drosha-DGCR8 complex. Collectively, our work establishes new factors in the scaRNP biogenesis pathway and adds to the ever-expanding list of noncanonical functions for the microprocessor complex.

A new class of isotropic generators for developing 6-DOF isotropic manipulators

Robotica ◽  
2008 ◽  
Vol 26 (5) ◽  
pp. 619-625 ◽  
Author(s):  
K. Y. Tsai ◽  
T. K. Lee ◽  
Y. S. Jang
Keyword(s):  
Reference Point ◽  
Parallel Manipulators ◽  
Geometric Constraint ◽  
Kinematic Chains ◽  
New Class ◽  
New Methods ◽  
Center Point ◽  
Different Types ◽  
Different Shapes ◽  
Straight Lines

SUMMARYDeveloping 6-DOF isotropic manipulators using isotropic generators is simple and efficient, and isotropic generators can be employed to develop serial, redundant, or parallel isotropic manipulators. An isotropic generator consists of a reference point and six straight lines. The existing generators, however, have one common geometric constraint: the reference point is equidistant from the six straight lines. Some practical isotropic designs might not be obtained due to this constraint. This paper proposes methods for developing new isotropic generators. The generators thus developed are not subject to the constraint, and the new methods allow us to specify the location of the tool center point, the size of the platform or the base, or the shape of isotropic parallel manipulators. Many new generators are presented to develop 6-DOF parallel manipulators with different shapes or different types of kinematic chains.

ON A MULTIVARIATE GENERALIZED POLYA PROCESS WITHOUT REGULARITY PROPERTY

2019 ◽  
Vol 34 (4) ◽  
pp. 484-506
Author(s):  
Ji Hwan Cha ◽  
F.G. Badía
Keyword(s):  
Regularity Property ◽  
Dependence Structure ◽  
Counting Processes ◽  
Multiple Events ◽  
New Class ◽  
Different Types ◽  
Polya Process ◽  
Multivariate Dependence ◽  
Pólya Process ◽  
Stochastic Properties

Most of the multivariate counting processes studied in the literature are regular processes, which implies, ignoring the types of the events, the non-occurrence of multiple events. However, in practice, several different types of events may occur simultaneously. In this paper, a new class of multivariate counting processes which allow simultaneous occurrences of multiple types of events is suggested and its stochastic properties are studied. For the modeling of such kind of process, we rely on the tool of superposition of seed counting processes. It will be shown that the stochastic properties of the proposed class of multivariate counting processes are explicitly expressed. Furthermore, the marginal processes are also explicitly obtained. We analyze the multivariate dependence structure of the proposed class of counting processes.

LncRNAs: Master Regulators in Disease and Cancer

2020 ◽  
Vol 14 (02) ◽  
pp. 79-89
Author(s):  
Ying Chen ◽  
Vinay Tergaonkar
Keyword(s):  
Cancer Progression ◽  
Therapeutic Intervention ◽  
Tumor Suppressors ◽  
Expression Patterns ◽  
Master Regulators ◽  
New Class ◽  
Non Coding Rna ◽  
Different Types ◽  
Cancer Transcriptome ◽  
Long Non Coding Rna

Long non-coding RNA (lncRNA) is a new class of endogenous molecules identified in recent years. Studies on the cancer transcriptome have identified a number of lncRNAs with distinct expression patterns in different types of cancer, indicating that this populous group of molecules can modulate cancer progression. In addition, advances in revealing the molecular principles of cancer-associated lncRNAs made them amenable for therapeutic intervention. Although more than 50,000 lncRNAs have been identified, their functions in cellular homeostasis and pathophysiological processes remain largely uncharacterized. In this review, we summarize cancer-related lncRNAs that have been identified in recent years and discuss their mechanistic roles as oncogenes or tumor suppressors. These findings provide insights into clinical application of lncRNAs as biomarkers or therapeutic targets.

scholarly journals Molecular determinants of metazoan tricRNA biogenesis

2019 ◽  
Vol 47 (12) ◽  
pp. 6452-6465 ◽  
Author(s):  
Casey A Schmidt ◽  
Joseph D Giusto ◽  
Alicia Bao ◽  
Anita K Hopper ◽  
A Gregory Matera
Keyword(s):  
Base Pair ◽  
Fruit Fly ◽  
Trna Genes ◽  
Cis Acting ◽  
Processing Enzymes ◽  
New Class ◽  
Weak Bases ◽  
Molecular Determinants ◽  
Intron Removal

Abstract Mature tRNAs are generated by multiple post-transcriptional processing steps, which can include intron removal. Recently, we discovered a new class of circular non-coding RNAs in metazoans, called tRNA intronic circular (tric)RNAs. To investigate the mechanism of tricRNA biogenesis, we generated constructs that replace native introns of human and fruit fly tRNA genes with the Broccoli fluorescent RNA aptamer. Using these reporters, we identified cis-acting elements required for tricRNA formation in vivo. Disrupting a conserved base pair in the anticodon-intron helix dramatically reduces tricRNA levels. Although the integrity of this base pair is necessary for proper splicing, it is not sufficient. In contrast, strengthening weak bases in the helix also interferes with splicing and tricRNA production. Furthermore, we identified trans-acting factors important for tricRNA biogenesis, including several known tRNA processing enzymes such as the RtcB ligase and components of the TSEN endonuclease complex. Depletion of these factors inhibits Drosophila tRNA intron circularization. Notably, RtcB is missing from fungal genomes and these organisms normally produce linear tRNA introns. Here, we show that in the presence of ectopic RtcB, yeast lacking the tRNA ligase Rlg1/Trl1 are converted into producing tricRNAs. In summary, our work characterizes the major players in eukaryotic tricRNA biogenesis.

scholarly journals Structured RNA Markers for Genotyping of Tick-Borne Encephalitis Virus

2018 ◽  
Vol 13 (1) ◽  
pp. 13-37
Author(s):  
V.D. Gusev ◽  
L.A. Miroshnichenko ◽  
T.N. Titkova ◽  
Yu.P. Dzhioev ◽  
I.V. Kozlova ◽  
...  
Keyword(s):  
Clinical Manifestations ◽  
Encephalitis Virus ◽  
Correct Identification ◽  
Disease Treatment ◽  
Pathogenic Potential ◽  
Tick Borne Encephalitis ◽  
Comprehensive Information ◽  
Different Types ◽  
Rna Fragments ◽  
Tick Borne Encephalitis Virus

Tick-borne encephalitis is one of the most dangerous natural focal infections. The causative agent of the disease is tick-borne encephalitis virus (TBEV ) transmitted by ticks . There are three main subtypes of TBEV with different clinical manifestations of the disease, but existence of other subtypes is also possible. Effectiveness of the disease treatment can largely depend on the correct identification of TBEV genotype. Comprehensive information about the genotype is contained in the full coding sequence of TBEV genome. А limited number of genotyping markers can be extracted from it in the form of relatively short structured RNA fragments. In this paper, a rather general approach to the isolation of structured RNA markers for the genotyping of TBEV is formulated. Three types of structures are considered: periodicity, fractal-like constructs and compactly localized combinations of different types of repetitions. The choice of these structures for the purposes of genotyping and their possible role in the formation of the pathogenic potential of the virus is substantiated. The approach was tested on the full coding sequences of TBEV (161 strains). Examples of the most characteristic markers of each of the three types are given.

scholarly journals Intelligent classification of platelet aggregates by agonist type

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Yuqi Zhou ◽  
Atsushi Yasumoto ◽  
Cheng Lei ◽  
Chun-Jung Huang ◽  
Hirofumi Kobayashi ◽  
...  
Keyword(s):  
Cancer Metastasis ◽  
Underlying Mechanism ◽  
Clinical Diagnostics ◽  
New Class ◽  
Imaging Flow Cytometry ◽  
Different Types ◽  
Platelet Aggregates ◽  
High Throughput Imaging ◽  
Aggregation Of Platelets

Platelets are anucleate cells in blood whose principal function is to stop bleeding by forming aggregates for hemostatic reactions. In addition to their participation in physiological hemostasis, platelet aggregates are also involved in pathological thrombosis and play an important role in inflammation, atherosclerosis, and cancer metastasis. The aggregation of platelets is elicited by various agonists, but these platelet aggregates have long been considered indistinguishable and impossible to classify. Here we present an intelligent method for classifying them by agonist type. It is based on a convolutional neural network trained by high-throughput imaging flow cytometry of blood cells to identify and differentiate subtle yet appreciable morphological features of platelet aggregates activated by different types of agonists. The method is a powerful tool for studying the underlying mechanism of platelet aggregation and is expected to open a window on an entirely new class of clinical diagnostics, pharmacometrics, and therapeutics.

scholarly journals A unified theory for irresolute functions

2021 ◽  
Vol 25 (2) ◽  
pp. 307-313
Author(s):  
Bishwambhar Roy
Keyword(s):  
Generalized Topology ◽  
Unified Theory ◽  
Basic Properties ◽  
New Class ◽  
Different Types

In this paper, a new class called (µ, λ)θ -irresolute functions has been defined with the notion of generalized topology. We obtain some characterizations of such functions and some relations between similar types of functions are established. Some basic properties of such functions are also discussed. Such functions unify different types of weakly irresolute functions by T. Noiri.

scholarly journals Quasinormal modes of scalar and Dirac perturbations of Bardeen de Sitter black holes

2017 ◽  
Vol 26 (14) ◽  
pp. 1750160 ◽  
Author(s):  
Wadbor Wahlang ◽  
Piyush A. Jeena ◽  
Sayan Chakrabarti
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quasinormal Modes ◽  
Theory Of Relativity ◽  
De Sitter ◽  
Massive Scalar Field ◽  
Regular Black Holes ◽  
New Class ◽  
Different Types ◽  
External Form

So far the study of black hole perturbations has been mostly focused upon the classical black holes with singularities at the origin and hidden by event horizon. Compared to that, the regular black holes are a completely new class of solutions arising out of modification of general theory of relativity by coupling gravity to an external form of matter. Therefore it is extremely important to study the behavior of such regular black holes under different types of perturbations. Recently a new regular Bardeen black hole solution with a de Sitter branch has been proposed by Fernando [ arXiv:1611.05337 [gr-qc]]. We compute the quasi-normal (QN) frequencies for the regular Bardeen de Sitter (BdS) black hole due to massless and massive scalar field perturbations as well as the massless Dirac perturbations. We analyze the behavior of both real and imaginary parts of QN frequencies by varying different parameters of the theory.

Solution Methods for a New Class of Simple Model Neurons

2007 ◽  
Vol 19 (12) ◽  
pp. 3216-3225 ◽  
Author(s):  
Mark D. Humphries ◽  
Kevin Gurney
Keyword(s):  
Simple Model ◽  
Neuron Model ◽  
Solution Method ◽  
Cortical Cell ◽  
Spike Generation ◽  
Firing Patterns ◽  
New Class ◽  
Efficient Simulation ◽  
Different Types ◽  
Solution Methods

Izhikevich (2003) proposed a new canonical neuron model of spike generation. The model was surprisingly simple yet able to accurately replicate the firing patterns of different types of cortical cell. Here, we derive a solution method that allows efficient simulation of the model.

Alternative Explanations

2018 ◽  
Author(s):  
Jessica McCrory Calarco
Keyword(s):  
Formal Training ◽  
Gender And Race ◽  
New Class ◽  
Different Types

Chapter 7 answers a number of lingering questions about the processes that generate inequalities in schools. Drawing both on data from the current study and on an analysis of prior research, this chapter discusses the significance of class-based strategies and how they change as students move through school. It examines how gender and race might matter in shaping students’ interactions with teachers, how class-based patterns might vary across schools with different types of characteristics, and the extent to which students might learn class-based behaviors from their peers. The findings in this chapter highlight the difficulty involved in trying to learn new class-based behaviors, either through exposure to peers or through more formal training.

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