Insights into nucleo-cytoplasmic transport mechanisms utilized by retroviral trans-activators / Diana Palmeri.

Format:

Book

Manuscript

Microformat

Thesis/Dissertation

Author/Creator:

Palmeri, Diana.

Contributor:

Emerson, Charles, advisor.

University of Pennsylvania.

Language:

English

Subjects (All):

Penn dissertations--Cell and molecular biology.

Cell and molecular biology--Penn dissertations.

Cell and Molecular Biology.

Academic Dissertations as Topic.

Medical Subjects:

Cell and Molecular Biology.

Academic Dissertations as Topic.

Local Subjects:

Penn dissertations--Cell and molecular biology.

Cell and molecular biology--Penn dissertations.

Physical Description:

x, 186 pages : illustrations ; 29 cm

Production:

1998.

Summary:

The nucleo-cytoplasmic transport of cellular and viral factors is an area of gene regulation that is just beginning to be understood. The study of human immunodeficiency virus-1 (HIV-1) Rev and human T-cell leukemia virus (HTLV-1) Rex, both post-transcriptional viral factors, have made the molecular mechanisms responsible for cellular import and export more tractable. Rev and Rex allow the transport of intron containing viral RNAs from the nucleus to the cytoplasm. Mutational analysis has shown that Rev has two major domains in the N-terminal and C-terminus, respectively. The N-terminal domain is responsible for viral RNA binding, multimerization and nuclear localization. Mutations in this region that knock out any one of these functions create recessive, non-functional mutants. Encoded within the C-terminal region is the activation domain, which is thought to interact with a cellular factor. Mutations in this region are trans-dominant and create non-functional proteins that cannot exit the nucleus. Part of this thesis examines the interaction of Rev's activation domain with a cellular factor. The factor is isolated through immuno-affinity chromatography and does not interact with the trans-dominant mutant, suggesting that it is a specific interaction.

Rev's activation domain was shown to be essential for its exit from the nucelus. Since Rex also encodes a nuclear export signal. Classical approaches to study nuclear transport such as assays showing sensitivity to a transcriptional inhibitor and somatic cell microinjection were utilized. Rex's nuclear import was also of interest since there is evidence that Rex's import may have unique aspects relative to the classical pathway. We pursued the characterization of this possibly novel nuclear import pathway and demonstrated that Rex enters the nucleus in an $\alpha$ independent, yet $\beta$ dependent, manner.

The complete cycle of the nucleo-cytoplasmic trafficking of Rex and Rev was of interest in an attempt to better understand these post-transcriptional trans-activators. The insights obtained into these molecular mechanisms give a clearer view of the cellular pathways utilized by the virus and possible mechanisms that could be used by the cell itself.

Notes:

Adviser: Charles Emerson.

Thesis (Ph.D. in Cell and Molecular Biology) -- University of Pennsylvania, 1998.

Includes bibliographical references.

Local Notes:

University Microfilms order no.: 98-40222.

OCLC:

187472974