Role of retroviral genomic RNA sequences in the maintenance of balanced splicing: The avian sarcoma virus as a model system.

Format:

Book

Thesis/Dissertation

Author/Creator:

Bouck, John Benjamin.

Contributor:

Skalka, Ann Marie, advisor.

University of Pennsylvania.

Language:

English

Subjects (All):

Microbiology.

Molecular biology.

0307.

0410.

Penn dissertations--Cell and molecular biology.

Cell and molecular biology--Penn dissertations.

Local Subjects:

Penn dissertations--Cell and molecular biology.

Cell and molecular biology--Penn dissertations.

0307.

0410.

Physical Description:

211 pages

Contained In:

Dissertation Abstracts International 59-04B.

System Details:

Mode of access: World Wide Web.

text file

Summary:

Retroviruses utilize balanced splicing to express a full complement of gene products. Simple retroviruses, such as avian sarcoma virus (ASV), do not contain regulatory proteins that affect splicing and, thus, the control of balanced splicing is encoded entirely in cis on the viral RNA. The contribution of RNA elements to balanced splicing was examined through the combined use of in vivo and in vitro characterization of viral mutants. The investigations have demonstrated that the polypyrimidine tract (PPyT) can be an important component of balanced splicing and that this element may play different roles at different stages within the splicing reaction. Early in the splicing pathway the PPyT interacts with the splicing factor U2AF and this interaction is facilitated by sequences found in the downstream exon. Abrogation of this interaction results in diminished splicing and the accumulation of unspliced transcripts. Later in the splicing pathway, mutations can cause stalling of the splicing reaction as indicated by the accumulation of intermediates. This stalling correlates with increased association of the splicing factor SAP49 and increased accumulation of unspliced RNA. The mechanism by which stalled splicing reactions might promote the cytoplasmic accumulation of unspliced RNA was investigated.

The results of these experiments demonstrate that the PPyT can play an important role late in the splicing reaction and that this element is likely to affect the binding of at least two proteins to the pre-mRNA. Examination of the sequence requirements of the PPyT reveals that they are complex and this likely reflects the binding of multiple proteins to this element. Lastly, a powerful in vivo selection system to address the role of RNA elements involved in splicing has been described. In combination with in vitro analysis this method provides insight into the mechanism of RNA splicing used by both viruses and the cell.

Notes:

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

Source: Dissertation Abstracts International, Volume: 59-04, Section: B, page: 1491.

Adviser: Ann Marie Skalka.

Local Notes:

School code: 0175.

ISBN:

9780591827132

Access Restriction:

Restricted for use by site license.