Footprint Analysis of the Transcriptional Control of Glycogen Phosphorylase 2 in Dictyostelium Discoideum

Glycogen phosphorylase 2 (gp-2) is a key enzyme during the development of Dictyostelium discoideum. The gp-2 enzyme breaks down glycogen into glucose monomers that are subsequently used to synthesize the terminal end products of cellular differentiation. This gene is an ideal candidate for studying the process of selective gene expression because its product figures so prominently in the development of this organism, implying a dependable control mechanism responsible for its developmentally regulated expression. I present in this thesis the identification of several putative cis-acting elements of gp-2 as revealed through footprint analysis. Due to the extreme AT-bias characteristic of Dictyostelium promoters, footprinting conditions required intensive optimization with respect to template, nonspecific competitor, source of protein extract and DNase I digestion. Using an endlabeled fragment containing seven repeated sequences (3 TA boxes [TAATTATA], 2 TAG boxes [TAAAAATGGT] and 2 C boxes [ACCCACT]), purified replication protein A and several developmental nuclear extracts were tested for DNA binding activity. Small footprints were observed on the TAG and C boxes of the promoter for both protein sources. However, using a more sensitive footprinting strategy involving multiple rounds of primer extension, larger footprints spanning the same promoter regions were detected. In both cases, the appearance of the footprints coincided with the documented transcriptional activity of the gene. It can be concluded from the data obtained that the TAG and C boxes are very likely cis-acting elements involved in the regulation of gp-2 expression.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Biology (Molecular and Cellular)

Department dc:contributor.department

Biology (Molecular and Cellular)

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1997

Author dc:creator

• Col, Bekir

Chair dc:contributor.committeechair

• Rutherford, Charles L.

Committee members dc:contributor.committeemember

• Esen, Asim
• Stevens, Ann M.
• Favis, Reyna

• cell differentiation
• Dictyostelium discoideum
• DNase I footprint analysis
• transcription
• gene expression
• AT-rich
• looping
• large footprints
• replication protein A

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

etd-0598-12052

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/33366