Identification of the Nuclear Localization Signal Region of Duck Enteritis Virus UL14 and Its Interaction with VP16

Identification and subcellular localization of proteins that interact with Duck plague virus pUL14 in infected host cells

Duck plague (DP), which is caused by duck plague virus (DPV), is an infectious disease that severely harms the waterfowl breeding industry. The UL14 protein (pUL14) is a tegument protein encoded by the UL14 gene, which is located in the unique long (UL) region of the DPV genome. DPV pUL14 plays a crucial role in viral replication, likely by interacting with host and viral proteins that have yet to be identified. In this study, glutathione-S-transferase (GST) pull-down combined with liquid chromatography-mass spectrometry (LC-MS/MS) was employed to identify pUL14-interacting proteins in DPV-infected cells. A total of 281 host proteins and 58 viral proteins that interacted with pUL14 were identified. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses revealed that the identified proteins could be assigned to several different subcellular locations and functional classes. These proteins are associated mainly with the regulation of biological processes, RNA biosynthetic processes, and nuclear export. In addition, four viral proteins of interest, the α-gene transducing factor (α-TIF) pUL48, the nuclear egress complex (NEC) proteins pUL31/34, and pUL51, a protein involved in secondary envelopment, were validated by coimmunoprecipitation (co-IP) to interact with DPV pUL14. Additionally, the nuclear export signal (NES) was identified in a leucine-rich region at aa 77-87 (77VQTKIEEQLAI87) of DPV pUL14. The interactome data between DPV pUL14 and host/viral proteins contribute to understanding the role of DPV pUL14 in the replication of DPV.

Multiple functions of the herpesvirus UL14 gene product in viral infection

Herpesviruses are a family of double-stranded DNA viruses with a tegument structure and a genome composed of a single sequence and terminal repeat (TR) sequences. The herpesvirus UL14 gene encodes the protein UL14 (pUL14), which has various subcellular localizations and plays a vital role in regulating immediate-early (IE) gene transcription and expression, influences the intracellular localization patterns of several proteins belonging to the capsid and the DNA packaging machinery, participates in secondary envelopment, and influences viral particle release. Additionally, pUL14 has roles in maintaining cellular homeostasis and preventing apoptosis. This review discusses how pUL14 engages in the life cycle of herpesviruses and provides new ideas for further research on pUL14's function in viral infection.

The precise function of alphaherpesvirus tegument proteins and their interactions during the viral life cycle

Alphaherpesvirus is a widespread pathogen that causes diverse diseases in humans and animals and can severely damage host health. Alphaherpesvirus particles comprise a DNA core, capsid, tegument and envelope; the tegument is located between the nuclear capsid and envelope. According to biochemical and proteomic analyses of alphaherpesvirus particles, the tegument contains at least 24 viral proteins and plays an important role in the alphaherpesvirus life cycle. This article reviews the important role of tegument proteins and their interactions during the viral life cycle to provide a reference and inspiration for understanding alphaherpesvirus infection pathogenesis and identifying new antiviral strategies.

Duck Plague Virus pUL48 Protein Activates the Immediate-Early Gene to Initiate the Transcription of the Virus Gene

Duck plague caused by the duck plague virus (DPV) is an infectious disease that seriously harms the waterfowl breeding industry. The VP16 protein of α herpesvirus can bind to specific cis-acting elements upstream of the promoter of the immediate-early (IE, α) gene to promote the transcription of the IE gene, so it is also called the trans-inducer of IE gene (α-TIF). However, no studies on DPV α-TIF have been reported. This study investigated the DPV pUL48, a homolog of HSV-1 VP16, transcriptional activation region, target sequence, and viral protein affecting its transcriptional activation using a dual-luciferase reporter gene detection system, and pUL48 was identified as the α-TIF of DPV. (1) The regulation of pUL48 on DPV different gene promoters showed that pUL48 could activate all the promoters of IE genes (ICP4, ICP22, and ICP27) but not the promoters of early and late genes. (2) The activity of pUL48 to ICP4 and ICP22 promoters with different upstream lengths showed that pUL48 activated ICP4 and ICP22 promoters by acting on TAATGA (T) TAT element upstream of ICP4 promoter and TAATTATAT element upstream of ICP22 promoter, respectively. (3) Transcriptional activation of IE gene by truncated proteins of different lengths at the N-terminal of pUL48 was detected. The results showed that the transcriptional activation domain of pUL48 was amino acids 1–60 at the N-terminal, and amino acids 1–20 was its core region. In addition, it was found that pUL14, pUL46, and pUL47 significantly promoted the transcriptional activation of pUL48. The effects of loss of pUL47 and its nuclear localization signal on the nuclear entry and transcriptional activation function of pUL48 were further examined. The results showed that pUL47 could promote the nuclear entry of pUL48 through its nuclear localization signal at positions 40–50 and 768–777 amino acids, thus, enhancing the transcriptional activation function of pUL48 and synergistic promotion of viral gene transcription.

SARS-CoV-2: its potential neurological manifestations and plausible mechanism: a review article

Coronavirus disease (COVID-19) was first identified in late December 2019. The disease began in Wuhan, Hubei province in China and since then it has spread quickly to many countries all over the world. COVID-19 is caused by a novel coronavirus, named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The virus was majorly seen to overwhelm the respiratory system with mild to severe acute respiratory syndrome considered pathognomic for the disease. However, with time a plethora of symptoms was observed in the patients infected with COVID-19 including strong evidence for neurological symptoms. Evidence suggests that the virus has both central and peripheral nervous system manifestations. Patients, particularly those who suffer from a severe illness, have a central nervous system (CNS) involvement and neurological manifestations. There is precise and targeted documentation of neurological symptoms with details of clinical, neurological, and electrophysiological findings. This review article thus gives an insight into the neuro-invasive potential of COVID-19 and discusses the possible pathogenesis.