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Full-Text Articles in Virology

Efficient Transcriptional Activation Of Many Simple Modular Promoters By Simian Virus 40 Large T Antigen., Philip W. Rice, Charles N. Cole Nov 1993

Efficient Transcriptional Activation Of Many Simple Modular Promoters By Simian Virus 40 Large T Antigen., Philip W. Rice, Charles N. Cole

Dartmouth Scholarship

Simian virus 40 (SV40) large T antigen is a multifunctional protein which plays central roles during both lytic and transforming infections by SV40. It is a potent transcriptional activator and increases expression from the SV40 late promoter and from several cellular promoters. To understand better the transcriptional activation activity of large T antigen, we examined its ability to transactivate a set of simple modular promoters containing one of four upstream activation sequences coupled with one of three different TATA box sequences originally constructed and studied by Taylor and Kingston (Mol. Cell. Biol. 10:165-175, 1990). Large T antigen activated transcription from …


Molecular Cloning Of Infectious Ecotropic Murine Leukemia Virus Ak7 From An Emv-14-Positive Akxl-5 Mouse And The Resistance Of Ak7 To Recognition By Cytotoxic T Lymphocytes., Hillary D. White, William R. Green, Nuria R. Giné Aug 1993

Molecular Cloning Of Infectious Ecotropic Murine Leukemia Virus Ak7 From An Emv-14-Positive Akxl-5 Mouse And The Resistance Of Ak7 To Recognition By Cytotoxic T Lymphocytes., Hillary D. White, William R. Green, Nuria R. Giné

Dartmouth Scholarship

The AKXL-5 recombinant inbred mouse strain is positive for the endogenous ecotropic murine leukemia virus emv-14, the only emv present in its germ line. emv-14 is of particular interest because spleen cells expressing emv-14 virus escape recognition by anti-AKR/Gross virus-specific cytotoxic T lymphocytes. We report here the isolation and characterization of a replication-competent emv clone, pAK7, derived from an AKXL-5 mouse. This clone is novel in that it encodes a variant ecotropic murine leukemia virus that, when expressed in SC.Kb target cells, fails to be recognized efficiently by anti-AKR/Gross virus cytotoxic T lymphocytes. The pAK7 clone can therefore be used …


Simian Immunodeficiency Virus Mutants Resistant To Serum Neutralization Arise During Persistent Infection Of Rhesus Monkeys, Dawn P. Wooley, Catherine Collignon, Ronald C. Desrosiers Jul 1993

Simian Immunodeficiency Virus Mutants Resistant To Serum Neutralization Arise During Persistent Infection Of Rhesus Monkeys, Dawn P. Wooley, Catherine Collignon, Ronald C. Desrosiers

Neuroscience, Cell Biology & Physiology Faculty Publications

We previously described the pattern of sequence variation in gp120 following persistent infection of rhesus monkeys with the pathogenic simian immunodeficiency virus SIVmac239 molecular clone (D.P.W. Burns and R.C. Desrosiers, J. Virol. 65:1843, 1991). Sequence changes were confined largely to five variable regions (V1 to V5), four of which correspond to human immunodeficiency virus type 1 (HIV-1) gp120 variable regions. Remarkably, 182 of 186 nucleotide substitutions that were documented in these variable regions resulted in amino acid changes. This is an extremely nonrandom pattern, which suggests selective pressure driving amino acid changes in discrete variable domains. In the present study, …


Two Factors That Bind To Highly Conserved Sequences In Mammalian Type C Retroviral Enhancers., Nancy R. Manley, Mary M. O'Connell, Wanwen Sun, Nancy A. Speck, Nancy Hopkins Apr 1993

Two Factors That Bind To Highly Conserved Sequences In Mammalian Type C Retroviral Enhancers., Nancy R. Manley, Mary M. O'Connell, Wanwen Sun, Nancy A. Speck, Nancy Hopkins

Dartmouth Scholarship

The transcriptional enhancers of the Moloney and Friend murine leukemia viruses (MLV) are important determinants of viral pathogenicity. We used electrophoretic mobility shift and methylation interference assays to study nuclear factors which bind to a region of these enhancers whose sequence is identical between Moloney and Friend viruses and particularly highly conserved among 35 mammalian type C retroviruses whose enhancer sequences have been aligned (E. Golemis, N. A. Speck, and N. Hopkins, J. Virol. 64:534-542, 1990). Previous studies identified sites for the leukemia virus factor b (LVb) and core proteins in this region (N. A. Speck and D. Baltimore, Mol. …


Characterization Of A Protein That Binds Multiple Sequences In Mammalian Type C Retrovirus Enhancers., Wanwen Sun, Mary M. O'Connell, Nancy A. Speck Apr 1993

Characterization Of A Protein That Binds Multiple Sequences In Mammalian Type C Retrovirus Enhancers., Wanwen Sun, Mary M. O'Connell, Nancy A. Speck

Dartmouth Scholarship

Mammalian type C retrovirus enhancer factor 1 (MCREF-1) is a nuclear protein that binds several directly repeated sequences (CNGGN6CNGG) in the Moloney and Friend murine leukemia virus (MLV) enhancers (N. R. Manley, M. O'Connell, W. Sun, N. A. Speck, and N. Hopkins, J. Virol. 67:1967-1975, 1993). In this paper, we describe the partial purification of MCREF-1 from calf thymus nuclei and further characterize the binding properties of MCREF-1. MCREF-1 binds four sites in the Moloney MLV enhancer and three sites in the Friend MLV enhancer. Ethylation interference analysis suggests that the MCREF-1 binding site spans two adjacent minor grooves of …


Book Review: The Baculovirus Expression System: A Laboratory Guide (1992) King, L. A. & Possee, R. D., David D. Dunigan Jan 1993

Book Review: The Baculovirus Expression System: A Laboratory Guide (1992) King, L. A. & Possee, R. D., David D. Dunigan

Nebraska Center for Virology: Faculty Publications

The power of molecular biology is unleashed with the ability to clone and sequence genes, and then express these genes in heterologous systems. This sets the stage for the full analysis of proteins that are otherwise difficult to isolate and/or purify, especially when present at very low copy number per cell or when isolated from relatively precious materials. Overexpression of protein is now possible in a number of systems including prokaryotes (e.g., E. coli) and various eukaryotes (yeast, insects, and plants). The issue then becomes, which system (1) most closely reflects the homologous expression with respect to posttranslational modifications, …