Numerous variants of leucine rich repeats in proteins from nucleo-cytoplasmic large DNA viruses

Gene ◽  
2022 ◽  
pp. 146156
Author(s):  
Norio Matsushima ◽  
Robert H. Kretsinger
Author(s):  
Norio Matsushima ◽  
Hiroki Miyashita ◽  
Shinsuke Tamaki ◽  
Robert H. Kretsinger

Author(s):  
Norio Matsushima ◽  
Robert H. Kretsinger

: Leucine-rich repeats (LRRs) occurring in tandem are 20-29 amino acids long. Eleven LRR types have been recognized. Sequence features of LRRs from viruses were investigated using over 600 LRR proteins from 89 species. Before, metagenome data of nucleo-cytoplasmic large dsDNA viruses (NCLDVs) have been published; the 2,074 NCLDVs encode 199,021 proteins. From the NCLDVs, 549 LRR proteins were identified and analyzed. A comprehensive analysis of TpLRR and FNIP that belong to an LRR class was first performed. The repeating unit lengths (RULs) in five types are 19 residues, which are the shortest among all LRRs. Some RULs are one to five residues shorter than those of the known, corresponding LRR types. The shrinking of RUL is also observed in FNIP. The conserved hydrophobic residues, such as Leu, Val or Ile, in the consensus sequences are frequently substituted by cysteine at one or two positions. Some unique LRR types that are different from those identified previously have been observed. The present study confirms the previous result that the sequence novelty is a general feature of viral LRR proteins.


Author(s):  
T. G. Sarphie ◽  
C. R. Comer ◽  
D. J. Allen

Previous ultrastructural studies have characterized surface morphology during norma cell cycles in an attempt to associate specific changes with specific metabolic processes occurring within the cell. It is now known that during the synthetic ("S") stage of the cycle, when DNA and other nuclear components are synthesized, a cel undergoes a doubling in volume that is accompanied by an increase in surface area whereby its plasma membrane is elaborated into a variety of processes originally referred to as microvilli. In addition, changes in the normal distribution of glycoproteins and polysaccharides derived from cell surfaces have been reported as depreciating after cellular transformation by RNA or DNA viruses and have been associated with the state of growth, irregardless of the rate of proliferation. More specifically, examination of the surface carbohydrate content of synchronous KB cells were shown to be markedly reduced as the cell population approached division Comparison of hamster kidney fibroblasts inhibited by vinblastin sulfate while in metaphase with those not in metaphase demonstrated an appreciable decrease in surface carbohydrate in the former.


Author(s):  
A. E. Vatter ◽  
J. Zambernard

Oncogenic viruses, like viruses in general, can be divided into two classes, those that contain deoxyribonucleic acid (DNA) and those that contain ribonucleic acid (RNA). The RNA viruses have been recovered readily from the tumors which they cause whereas, the DNA-virus induced tumors have not yielded the virus. Since DNA viruses cannot be recovered, the bulk of present day investigations have been concerned with RNA viruses.The Lucké renal adenocarcinoma is a spontaneous tumor which occurs in northern leopard frogs (Rana pipiens) and has received increased attention in recent years because of its probable viral etiology. This hypothesis was first advanced by Lucké after he observed intranuclear inclusions in some of the tumor cells. Tumors with inclusions were examined at the fine structural level by Fawcett who showed that they contained immature and mature virus˗like particles.The use of this system in the study of oncogenic tumors offers several unique features, the virus has been shown to contain DNA and it can be recovered from the tumor, also, it is temperature sensitive. This latter feature is of importance because the virus can be transformed from a latent to a vegetative state by lowering or elevating the environmental temperature.


Author(s):  
S.I. Kutukova ◽  
A.B. Chukhlovin ◽  
A.I. Yaremenko ◽  
Yu.V. Ivaskova ◽  
A.Ya. Razumova ◽  
...  

The aim of the study was to assess the prevalence of DNA viruses (HSV I and II, CMV, EBV, HPV6.11, HPV16 and HPV18) in the native oral mucosa of healthy volunteers (n=50; 30 men (60.0%), 20 women (40.0%); 25—74 years, median age — 55.0 years (95% CI 47.60-56.76)). All samples of the normal oral mucosa were detected by real-time PCR to detect viral DNA. The majority of the examined — 76% (33/50) — revealed the DNA: one type of viral DNA in 17 (38.00%) of the examined, a combination of the two types in 14 (28.00%). In the normal oral mucosa, DNA of Epstein-Barr virus was significantly more often detected: 15 (30.00%) (p = 0.0276) and human papilloma viruses 27 (54.00%) (p <0.0001), especially HPV-18 (24 (48.00%)): mono-association in 9 (18.00%) examined and in 7 (14.00%) in combination with EBV DNA (p = 0.0253).


2020 ◽  
Vol 16 (5) ◽  
pp. 677-688 ◽  
Author(s):  
Sandra Piras ◽  
Paola Corona ◽  
Roberta Ibba ◽  
Federico Riu ◽  
Gabriele Murineddu ◽  
...  

Background: Coxsackievirus infections are associated with cases of aseptic meningitis, encephalitis, myocarditis, and some chronic disease. Methods: A series of benzo[d][1,2,3]triazol-1(2)-yl derivatives (here named benzotriazol-1(2)-yl) (4a-i, 5a-h, 6a-e, g, i, j and 7a-f, h-j) were designed, synthesized and in vitro evaluated for cytotoxicity and antiviral activity against two important human enteroviruses (HEVs) members of the Picornaviridae family [Coxsackievirus B 5 (CVB-5) and Poliovirus 1 (Sb-1)]. Results: Compounds 4c (CC50 >100 μM; EC50 = 9 μM), 5g (CC50 >100 μM; EC50 = 8 μM), and 6a (CC50 >100 μM; EC50 = 10 μM) were found active against CVB-5. With the aim of evaluating the selectivity of action of this class of compounds, a wide spectrum of RNA (positive- and negativesense), double-stranded (dsRNA) or DNA viruses were also assayed. For none of them, significant antiviral activity was determined. Conclusion: These results point towards a selective activity against CVB-5, an important human pathogen that causes both acute and chronic diseases in infants, young children, and immunocompromised patients.


Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 779
Author(s):  
Man Teng ◽  
Yongxiu Yao ◽  
Venugopal Nair ◽  
Jun Luo

In recent years, the CRISPR/Cas9-based gene-editing techniques have been well developed and applied widely in several aspects of research in the biological sciences, in many species, including humans, animals, plants, and even in viruses. Modification of the viral genome is crucial for revealing gene function, virus pathogenesis, gene therapy, genetic engineering, and vaccine development. Herein, we have provided a brief review of the different technologies for the modification of the viral genomes. Particularly, we have focused on the recently developed CRISPR/Cas9-based gene-editing system, detailing its origin, functional principles, and touching on its latest achievements in virology research and applications in vaccine development, especially in large DNA viruses of humans and animals. Future prospects of CRISPR/Cas9-based gene-editing technology in virology research, including the potential shortcomings, are also discussed.


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