Functional analysis of the L Protein of Nipah Virus Using Minigenome System

2013 ◽  
Vol 3 (3) ◽  
pp. 36-42
Author(s):  
Ali Shahandeh ◽  
Keyword(s):  
Functional Analysis ◽  
Nipah Virus ◽  
L Protein ◽  
Minigenome System

scholarly journals Rift Valley fever virus minigenome system for investigating the role of L protein residues in viral transcription and replication

2019 ◽  
Author(s):  
Hanna Jérôme ◽  
Martin Rudolf ◽  
Michaela Lelke ◽  
Meike Pahlmann ◽  
Carola Busch ◽  
...  
Keyword(s):  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Regulatory Elements ◽  
Viral Transcription ◽  
Valley Fever ◽  
Replication Complex ◽  
L Protein ◽  
Minigenome System ◽  
Transcription And Replication

AbstractReplicon systems are important molecular tools for investigating the function of virus proteins and regulatory elements involved in viral RNA synthesis. We developed an ambisense minigenome system for Rift Valley fever virus (RVFV) to dissect the effects of L gene mutations on viral transcription versus replication. The S RNA segment with regulatory elements for ambisense gene expression served as backbone for the minigenome. Expression of the luciferase reporter gene allowed the overall activity of the RVFV replication complex to be assessed, while northern blot analysis enabled differentiation between synthesis of viral mRNA and replication intermediates. The functionality of the system was demonstrated by probing residues predictably involved in the active site of the cap-snatching endonuclease in the N-terminus of the L protein. Corresponding mutations led to a selective defect in the viral mRNA synthesis as described for other viruses of theBunyaviralesorder. The analysis of further L gene mutants revealed an essential and specific role of a C-terminal region in the RVFV L protein in viral transcription. In summary, the established minigenome system is suitable for functional testing of the relevance of residues for viral transcription and replication. It may be used to validate hypotheses arising from structural or biochemical investigations of the RVFV replication complex.

scholarly journals Functional Analysis of the Fusion and Attachment Glycoproteins of Mojiang Henipavirus

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 517
Author(s):  
Sofia Cheliout Da Silva ◽  
Lianying Yan ◽  
Ha V. Dang ◽  
Kai Xu ◽  
Jonathan H. Epstein ◽  
...  
Keyword(s):  
Functional Analysis ◽  
Cell Fusion ◽  
Sequence Data ◽  
Nipah Virus ◽  
Hendra Virus ◽  
Soluble Form ◽  
Fusion Activity ◽  
Low Levels ◽  
Entry Receptor ◽  
Functional Defects

Mojiang virus (MojV) is the first henipavirus identified in a rodent and known only by sequence data, whereas all other henipaviruses have been isolated from bats (Hendra virus, Nipah virus, Cedar virus) or discovered by sequence data from material of bat origin (Ghana virus). Ephrin-B2 and -B3 are entry receptors for Hendra and Nipah viruses, but Cedar virus can utilize human ephrin-B1, -B2, -A2 and -A5 and mouse ephrin-A1. However, the entry receptor for MojV remains unknown, and its species tropism is not well characterized. Here, we utilized recombinant full-length and soluble forms of the MojV fusion (F) and attachment (G) glycoproteins in membrane fusion and receptor tropism studies. MojV F and G were functionally competent and mediated cell–cell fusion in primate and rattine cells, albeit with low levels and slow fusion kinetics. Although a relative instability of the pre-fusion conformation of a soluble form of MojV F was observed, MojV F displayed significantly greater fusion activity when heterotypically paired with Ghana virus G. An exhaustive investigation of A- and B-class ephrins indicated that none serve as a primary receptor for MojV. The MojV cell fusion phenotype is therefore likely the result of receptor restriction rather than functional defects in recombinant MojV F and G glycoproteins.

Case Formulation and Design of Behavioral Treatment Programs

2003 ◽  
Vol 19 (3) ◽  
pp. 164-174 ◽  
Author(s):  
Stephen N. Haynes ◽  
Andrew E. Williams
Keyword(s):  
Functional Analysis ◽  
Behavior Problems ◽  
Behavioral Treatment ◽  
Clinical Case ◽  
Relative Magnitude ◽  
Mechanisms Of Action ◽  
Treatment Programs ◽  
Case Formulation ◽  
Functional Relations ◽  
Causal Variables

Summary: We review the rationale for behavioral clinical case formulations and emphasize the role of the functional analysis in the design of individualized treatments. Standardized treatments may not be optimally effective for clients who have multiple behavior problems. These problems can affect each other in complex ways and each behavior problem can be influenced by multiple, interacting causal variables. The mechanisms of action of standardized treatments may not always address the most important causal variables for a client's behavior problems. The functional analysis integrates judgments about the client's behavior problems, important causal variables, and functional relations among variables. The functional analysis aids treatment decisions by helping the clinician estimate the relative magnitude of effect of each causal variable on the client's behavior problems, so that the most effective treatments can be selected. The parameters of, and issues associated with, a functional analysis and Functional Analytic Clinical Case Models (FACCM) are illustrated with a clinical case. The task of selecting the best treatment for a client is complicated because treatments differ in their level of specificity and have unequally weighted mechanisms of action. Further, a treatment's mechanism of action is often unknown.

The Social Order Yields to Functional Analysis

1958 ◽  
Vol 3 (6) ◽  
pp. 158-160
Author(s):  
LAWRENCE SCHLESINGER
Keyword(s):  
Functional Analysis ◽  
Social Order ◽  
The Social

A Functional Analysis of Reinforcement Within a Social System

1973 ◽  
Author(s):  
Robert M. Leve ◽  
Lydia Burdick ◽  
Patricia Fontaine
Keyword(s):  
Functional Analysis ◽  
Social System
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