Dr. James C. Alwine

Professor of Microbiology

Office Address:
314 Biomedical Research Bldg
U of Pennsylvania Medical Center
421 Curie Blvd
Philadelphia, PA 19104-6142
215-898-3256; FAX 215-573-3888
alwine@mail.med.upenn.edu

RESEARCH SUMMARY

Dr. Alwine's laboratory blends aspects of cell/molecular biology and virology to study the mechanisms which control cellular processes (transcription, cell cycle and apoptosis) and to determine how viruses alter these processes resulting in pathogenesis.

Projects in the lab:

1. Effects of viral proteins on cellular transcription, cell cycle regulation and apoptosis. Cells infected by DNA viruses, for example the papova and herpes viruses, undergo dramatic alterations in transcription, cell cycle control and the control of apoptosis. All of these alterations are mediated by viral proteins to assure that cellular growth and survival conditions are optimized for the support of viral replication. Under some conditions, and in some cells, these effects can result in transformation, altered cellular morphology and other pathogenesis. The viral proteins mediating these effects are usually the first viral proteins to be expressed in the infected cells; e.g. the early protein of simian virus 40 (SV40, a papova virus), called large T antigen (T Ag), and the major immediate early proteins (MIEPs) of human cytomegalovirus (HCMV, a herpesvirus). Members of the Alwine laboratory have shown that T Ag and the MIEPs transcriptionally activate both viral and cellular promoters through direct interactions with cellular transcription factors and the basal transcription apparatus. Specifically, the viral proteins function as components of the basal transcription factor TFIID, where they perform functions similar to the TATA binding protein ?associated factors (TAFs). These findings established that the viral proteins can be used as tools to study the molecular mechanisms of transcription, as well as to determine how DNA viruses alter transcription mechanisms to their advantage. Additional studies in the Alwine laboratory suggest that both T Ag and the MIEPs affect cell cycle control and inhibit apoptosis. The mechanisms mediating these effects are, at least in part, independent of the transcriptional activation functions. Our studies suggest that the effects of the viral proteins on the cell cycle and apoptosis result from alterations in the activities of cellular factors that are master controllers of cellular metabolism and growth. Hence a major goal of the laboratory is to utilize the viral proteins to examine and understand these fundamental cellular processes and how the alteration of these processes contributes to viral pathogenesis and transformation.

2. Studies in RNA processing. The studies of RNA processing performed in the Alwine laboratory focus primarily on the molecular mechanisms of polyadenylation, the process by which a precursor RNA is cleaved at its 3'-end and 250-300 adenosine residues are added to that end. However, polyadenylation is only one of several RNA processing events all of which occur in a coordinated fashion. In particular, polyadenylation is tightly coupled to splicing and each process exerts controls on the other to assure that processing is efficient and exact. Projects in the lab are designed to 1) define the structure and function of all the elements that make up polyadenylation signals; and determine how these elements function in polyadenylation and the coupling of polyadenylation and splicing. 2) Define the protein complexes that form on the RNA to mediate the coupling of splicing and polyadenylation. 3) Analyze the makeup of these complexes and determine how the components relate to other known RNA processing factors.

Some of the elements of a polyadenylation signal are unique to a specific gene; thus they provide specific targets for potential therapy through oligonucleotide-directed alteration of gene expression. We are presently examining means to both up regulate and down regulate specific gene expression through targeting polyadenylation signal elements. Thus understanding the structure and function of the elements of a polyadenylation signal provides the knowledge upon which such therapy may be developed.If you have question about molecular virology, graduate studies at Penn or rotation and thesis projects in Dr. Alwine's lab feel free to call, e-mail or drop by Dr. Alwine's office.

SELECTED RECENT PUBLICATIONS

Publications related to functions of T antigen and the HCMV MIEPs:

Lukac, D.M., Harel, N. and J.C. Alwine. (1997). TAF-Like Functions of the Human Cytomegalovirus Immediate Early Proteins. J..Virol. 71:7227-7239.

Damania, B., Mital, R. and J.C. Alwine. (1998). SV40 Large T Antigen Interacts with BRF and the SNAPc Complex for Transcriptional Activation of TATA-Containing Polymerase III Promoters. Mol. Cell. Biol. 18:1331-1338.

Harel, N.Y. and J.C. Alwine. (1998). Phosphorylation of HCMV Immediate-Early Proteins. J.Virol. 72:5481-5492.

Damania, B., Lieberman, P. and J.C. Alwine. (1998). SV40 Large T Antigen Stabilizes the TBP-TFIIA Complex on the TATA Element. Mol. Cell. Biol. 18:3926-3935.

Lukac, D.M. and J.C. Alwine. (1999). Effects of the human cytomegalovirus major immediate early proteins in controlling the cell cycle and inhibiting apoptosis: Studies in ts13 cells. J. Virol. 73:2825-2831.Publications related to polyadenylation and coupling of splicing and polyadenylation:

O'Connor, J.P., Alwine, J.C. and C.S. Lutz. (1997). Identification of a novel, non-snRNP protein complex containing U1A protein. RNA 3:1444-1455.

Lutz, C.S., Cooke, C.L., O'Connor, J.P., Kobayashi, R. and J.C. Alwine. (1998). The snRNP-Free U1A (SF-A) Complex: Identification of the Largest Subunit as PSF, the Polypyrimidine Track Binding Protein Associated Splicing Factor. RNA 4:1493-1499.

Cooke, C., Hans, H. and J.C. Alwine. (1999). Utilization of splicing elements and polyadenylation signal elements in the coupling of polyadenylation and last intron removal. Mol. Cell. Biol. 19:4971-4979.

Hans, H. and J.C. Alwine. (2000). Functionally Significant Secondary Structure of the Simian Virus 40 Late Polyadenylation Signal. MCB 20:2926-2932.