Katie Marcucci

RESEARCH

A major question in a science-based approach to risk assessment for xenotransplantation is whether primary human cells in a patient will be permissive for Porcine Endogenous Retrovirus (PERV) infection or whether they will have a viral assembly defect. Assembly and budding are two steps in retroviral assembly that are vital to viral particle production and propagation. However, mechanisms of retroviral assembly are incompletely understood. Recently three Gag protein motifs—P(T/S)AP, PPXY and YXXL—known as late (L) domains have been implicated in viral assembly roles. These motifs are highly conserved and have been shown to interact with a variety of cellular proteins, including those involved in the endosomal sorting and the endocytic pathways.

PERV is a gamma retrovirus most closely related to gibbon ape leukemia virus (GALV), feline leukemia virus (FLV) and murine leukemia virus (MLV). PERV productively infects certain human cell lines, HEK 293 and HeLa. Thus, the presence of multiple copies of PERV in all pig genomes raises the possibility of moving the retrovirus to immunosuppressed patients after a pig xenotransplant. In contrast, non-human primate cell lines are not productively infected by PERV despite finding high levels of proviral DNA integration and cellular mRNA production, suggesting a defect in viral assembly of unknown mechanism.

My research focuses on the role of late domains in PERV assembly and budding. The PERV Gag sequence contains two L domain motifs, PPPY and PSAP, found at amino acid residues 150-153 and 161-164 respectively. These domains are involved in binding a number of intracellular proteins and potentially creating functional complexes that regulate the movement of viral Gag protein to the cell surface for viral particle assembly. Our strategy will be to apply tools of molecular engineering and proteomics to determine the function of the Late Domains, the protein binding partners and study the structure and functional organization of these molecular complexes, all in an effort to unravel the basic mechanisms of retroviral particle assembly.

	Position: Graduate Student Birthday: 21st March 1981 Nationality: American Education: BA, Northwestern University, Evanston, IL, USA Email: katiem@scripps.edu	Curriculum vitae

RESEARCH A major question in a science-based approach to risk assessment for xenotransplantation is whether primary human cells in a patient will be permissive for Porcine Endogenous Retrovirus (PERV) infection or whether they will have a viral assembly defect. Assembly and budding are two steps in retroviral assembly that are vital to viral particle production and propagation. However, mechanisms of retroviral assembly are incompletely understood. Recently three Gag protein motifs—P(T/S)AP, PPXY and YXXL—known as late (L) domains have been implicated in viral assembly roles. These motifs are highly conserved and have been shown to interact with a variety of cellular proteins, including those involved in the endosomal sorting and the endocytic pathways. PERV is a gamma retrovirus most closely related to gibbon ape leukemia virus (GALV), feline leukemia virus (FLV) and murine leukemia virus (MLV). PERV productively infects certain human cell lines, HEK 293 and HeLa. Thus, the presence of multiple copies of PERV in all pig genomes raises the possibility of moving the retrovirus to immunosuppressed patients after a pig xenotransplant. In contrast, non-human primate cell lines are not productively infected by PERV despite finding high levels of proviral DNA integration and cellular mRNA production, suggesting a defect in viral assembly of unknown mechanism. My research focuses on the role of late domains in PERV assembly and budding. The PERV Gag sequence contains two L domain motifs, PPPY and PSAP, found at amino acid residues 150-153 and 161-164 respectively. These domains are involved in binding a number of intracellular proteins and potentially creating functional complexes that regulate the movement of viral Gag protein to the cell surface for viral particle assembly. Our strategy will be to apply tools of molecular engineering and proteomics to determine the function of the Late Domains, the protein binding partners and study the structure and functional organization of these molecular complexes, all in an effort to unravel the basic mechanisms of retroviral particle assembly.