Herpes Viral Proteins Manipulating the Peptide Transporter TAP

Author(s):  
E. Reits ◽  
A. Griekspoor ◽  
J. Neefjes
2020 ◽  
Vol 20 (18) ◽  
pp. 1900-1907
Author(s):  
Kasturi Sarkar ◽  
Parames C. Sil ◽  
Seyed Fazel Nabavi ◽  
Ioana Berindan-Neagoe ◽  
Cosmin Andrei Cismaru ◽  
...  

The global spread of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) that causes COVID-19 has become a source of grave medical and socioeconomic concern to human society. Since its first appearance in the Wuhan region of China in December 2019, the most effective measures of managing the spread of SARS-CoV-2 infection have been social distancing and lockdown of human activity; the level of which has not been seen in our generations. Effective control of the viral infection and COVID-19 will ultimately depend on the development of either a vaccine or therapeutic agents. This article highlights the progresses made so far in these strategies by assessing key targets associated with the viral replication cycle. The key viral proteins and enzymes that could be targeted by new and repurposed drugs are discussed.


2020 ◽  
Author(s):  
Laura Lafon-Hughes

BACKGROUND COVID-19 pandemic prompts the study of coronavirus biology and search of putative therapeutic strategies. OBJECTIVE To compare SARS-CoV-2 genome-wide structure and proteins with other coronaviruses, focusing on putative coronavirus-specific or SARS-CoV-2 specific therapeutic designs. METHODS The genome-wide structure of SARS-CoV-2 was compared to that of SARS and other coronaviruses in order to gain insights, doing a literature review through Google searches. RESULTS There are promising therapeutic alternatives. Host cell targets could be modulated to hamper viral replication, but targeting viral proteins directly would be a better therapeutic design, since fewer adverse side effects would be expected. CONCLUSIONS Therapeutic strategies (Figure 1) could include the modulation of host targets (PARPs, kinases) , competition with G-quadruplexes or nucleoside analogs to hamper RDRP. The nicest anti-CoV options include inhibitors of the conserved essential viral proteases and drugs that interfere ribosome slippage at the -1 PRF site.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Huiyun Wang ◽  
Chengcheng Li ◽  
Meng Peng ◽  
Lei Wang ◽  
Di Zhao ◽  
...  

Abstractβ-Conglycinin (β-CG), an anti-nutritional factor, is a major allergen in soybeans to induce intestinal dysfunction and diarrhea in neonatal animals, including piglets and human infants. This study with a piglet model determined the effects of N-acetylcysteine (NAC) on intestinal function and autophagy in response to β-CG challenge. Twenty-four 12-day-old piglets (3.44 ± 0.28 kg), which had been weaned at 7 days of age and adapted for 5 days after weaning, were randomly allocated to the control, β-CG, and β-CG + NAC groups. Piglets in the control group were fed a liquid diet containing 10% casein, whereas those in the β-CG and β-CG + NAC groups were fed the basal liquid diets containing 9.5% casein and 0.5% β-CG for 2 days. Thereafter, pigs in the β-CG + NAC group were orally administrated with 50 mg (kg BW)−1 NAC for 3 days, while pigs in the other two groups were orally administrated with the same volume of sterile saline. NAC numerically reduced diarrhea incidence (− 46.2%) and the concentrations of hydrogen peroxide and malondialdehyde, but increased claudin-1 and intestinal fatty-acid binding protein (iFABP) protein abundances and activities of catalase and glutathione peroxidase in the jejunum of β-CG-challenged piglets. Although β-CG challenge decreased the villus height, villus height/crypt depth ratio, and mRNA levels of claudin-1 and occludin, no significant differences were observed in these indices between the control and β-CG + NAC groups, suggesting the positive effects of NAC supplementation on intestinal mucosal barrier function. Moreover, NAC increased the concentrations of citrulline and D-xylose in the plasma, as well as the expression of genes for aquaporin (AQP) 3, AQP4, peptide transporter 1 (PepT1), sodium/glucose co-transporter-1 (SGLT-1), potassium inwardly-rectifying channel, subfamily J, member 13 (KCNJ13), and solute carrier family 1 member 1 (SLC1A1) in the jejunum, demonstrating that NAC augmented intestinal metabolic activity and absorptive function. Remarkably, NAC decreased Atg5 protein abundance and the LC3II/LC3I ratio (an indicator of autophagy) in the jejunum of β-CG-challenged piglets. Taken together, NAC supplementation improved intestinal function and attenuated intestinal autophagy in β-CG-challenged piglets.


Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1096
Author(s):  
Timothy W. Thoner ◽  
Xiang Ye ◽  
John Karijolich ◽  
Kristen M. Ogden

Packaging of segmented, double-stranded RNA viral genomes requires coordination of viral proteins and RNA segments. For mammalian orthoreovirus (reovirus), evidence suggests either all ten or zero viral RNA segments are simultaneously packaged in a highly coordinated process hypothesized to exclude host RNA. Accordingly, reovirus generates genome-containing virions and “genomeless” top component particles. Whether reovirus virions or top component particles package host RNA is unknown. To gain insight into reovirus packaging potential and mechanisms, we employed next-generation RNA-sequencing to define the RNA content of enriched reovirus particles. Reovirus virions exclusively packaged viral double-stranded RNA. In contrast, reovirus top component particles contained similar proportions but reduced amounts of viral double-stranded RNA and were selectively enriched for numerous host RNA species, especially short, non-polyadenylated transcripts. Host RNA selection was not dependent on RNA abundance in the cell, and specifically enriched host RNAs varied for two reovirus strains and were not selected solely by the viral RNA polymerase. Collectively, these findings indicate that genome packaging into reovirus virions is exquisitely selective, while incorporation of host RNAs into top component particles is differentially selective and may contribute to or result from inefficient viral RNA packaging.


Virus Genes ◽  
2021 ◽  
Vol 57 (2) ◽  
pp. 233-237
Author(s):  
Hendrik Reuper ◽  
Björn Krenz

AbstractTurnip mosaic virus (TuMV), belonging to the genus Potyvirus (family Potyviridae), has a large host range and consists of a single-stranded positive sense RNA genome encoding 12 proteins, including the P1 protease. This protein which is separated from the polyprotein by cis cleavage at its respective C-terminus, has been attributed with different functions during potyviral infection of plants. P1 of Turnip mosaic virus (P1-TuMV) harbors an FGSF-motif and FGSL-motif at its N-terminus. This motif is predicted to be a binding site for the host Ras GTPase-activating protein-binding protein (G3BP), which is a key factor for stress granule (SG) formation in mammalian systems and often targeted by viruses to inhibit SG formation. We therefore hypothesized that P1-TuMV might interact with G3BP to control and regulate plant SGs to optimize cellular conditions for the production of viral proteins. Here, we analyzed the co-localization of the Arabidopsis thaliana G3BP-2 with the P1 of two TuMV isolates, namely UK 1 and DEU 2. Surprisingly, P1-TuMV-DEU 2 co-localized with AtG3BP-2 under abiotic stress conditions, whereas P1-TuMV-UK 1 did not. AtG3BP-2::RFP showed strong SGs formation after stress, while P1-UK 1::eGFP maintained a chloroplastic signal under stress conditions, the signal of P1-DEU 2::eGFP co-localized with that of AtG3BP-2::RFP. This indicates a specific interaction between P1-DEU 2 and the AtG3BP family which is not solely based on the canonical interaction motifs.


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