Research Interests The pathogenic and cytotoxic effects of viruses are largely due to the expression of viral gene products. Therefore, the determinants of these outcomes are the mechanisms underlying the expression of viral genes. The hallmark of herpes simplex virus gene expression is the sequential and coordinately regulated expression of the approximately 80 viral genes. This regulation occurs largely through modulation of RNA polymerase II transcription. Two viral proteins, VP16 and ICP4, function to activate transcription of the five immediate early genes, and the remainder of the HSV genome, respectively. ICP4 is a large and structurally complex molecule. Previous studies from our lab have provided insight into how this molecule regulates transcription. Considerable effort has been placed on the mechanisms by which the major regulatory protein of HSV, ICP4, affects the pol II transcriptional apparatus of the cell resulting in the regulation of HSV genes. This involves structure/function studies of ICP4 using viral mutants in the context of infection and reconstituted in vitro transcription studies aimed at determining the molecular mechanism of ICP4 function. In addition, the actions of expressed viral proteins greatly perturbs cellular processes leading to changes in the abundance, activity, and subunit composition of cellular transcription factors. These changes contribute to the pathogenic and cytotoxic effects of HSV and also to the regulated cascade of HSV gene expression. We are using a combination of microarray analysis and protein biochemistry to determine what these changes are as well as their significance to viral gene expression. We have constructed a cDNA chip representing genes for approximately 1500 cellular transcription factors, including components of the basal transcription machinery, coactivator subunits, chromatin remodeling complexes, gene specific regulatory proteins, and viral proteins. The microarray data from infected cells is used to guide the subsequent biochemical experiments. HSV gene expression during lytic infection is contrasted by the ability to establish latency in PNS neurons. During latency, viral lytic gene expression does not occur, and the genome persists as an episomal element packaged in chromatin. Reactivation from latency presumably involves activation of the genome in the absence of VP16. One IE protein, ICP0, has been shown to be involved in the process of reactivation from latency in several model systems. ICP0 has also been shown to facilitate lytic viral gene expression. While its mechanism of action is unknown, it has been shown to interact with a ubiquitin proteinase and function as a ubiquitin E3 ligase. The use of mutants deficient in subsets of the IE proteins provides the means to examine viral gene expression and genome persistence in the absence of lytic gene expression in tissue culture. One mutant, d109, does not express any of the five IE proteins, is completely nontoxic, and establishes a long-term relationship with the cell. Gene expression from the persisting genomes is repressed, but can be induced by the addition of ICP0. Therefore, some of the events occurring in d109-infected tissue culture cells are similar to those that may occur with latent genomes in vivo. We are using this system to study the processes involved in the repression and reactivation of the HSV genome.   Selected Publications Livingston CM, DeLuca NA, Wilkinson DE, Weller SK. Oligomerization of ICP4 and rearrangement of heat shock proteins may be important for herpes simplex virus type 1 pre-replicative site formation. J Virol. 2008 Jul;82(13):6324-36. Epub 2008 Apr 23. Zabierowski SE, Deluca, NA. Stabilized binding of TBP to the TATA Box of HSV-1 early (tk) and late (gC) promotors by TFIIA AND ICP4. J Virol. 2008 Apr;82(7):3546-54. Epub 2008 Jan 23. Sampath P, Deluca NA. Binding of ICP4, TBP, and RNA POLII to herpes simplex virus, Type 1 immediate early, early and late promoters in virus-infected cells. J Virol. 2008 Mar;82(5):2339-49. Epub 2007 Dec 19. Terry-Allison T, Smith CA, DeLuca NA. Relaxed repression of herpes simplex virus type 1 genomes in Murine trigeminal neurons. J Virol. 2007 Nov;81(22):12394-405. Epub 2007 Sep 12. Kuddus RH, Deluca NA. DNA-dependent oligomerization of herpes simplex virus type 1 regulatory protein ICP4. J Virol. 2007 Sep;81(17):9230-7. Epub 2007 Jun 20. Complete Publication Listing   Grant Support NIH/NIAID: Virus-cell interactions affecting HSV gene expression. Principal Investigator NIH: Center for Neuroanatomy with neurotropic viruses. Director of HSV Core NIH/NIAID: Repression and activation of persisting HSV genomes. Principal Investigator NIH/NIAID: Virus-cell interactions affecting HSV gene expression. Principal Investigator   Other Links MGB Faculty Webpage University of Pittsburgh

Neal A DeLuca , Ph.D., Professor Office:  BST E1257 Lab:BST E1212,13,14 Phone:(412) 648-9947 Fax: (412) 624-0298 ndeluca@pitt.edu   Academic Affiliations Department of Microbiology and Molecular Genetics Member, Biochemistry and Molecular Genetics Graduate Program University of Pittsburgh   Education 1977 - B.S. Fundamental Sciences Lehigh University 1979 - M.S. Biophysics Pennsylvania State University 1981 - Ph.D. Biophysics Pennsylvania State University 1982-1986 - Postdoc Harvard Medical School at the Dana Farber Cancer Institute   Lab Personnel Peter Compel, Ph.D. Padma Sampath, Ph.D. Costas Hadjipanayis, M.D. Sara Jackson Trupta Purohit Brian Manning Kim Harrison Kurt D'Andrea Trevor Lester