Identification and Characterization of Control Elements within the Murine CD4 Gene

<p>The control of CD4 gene expression is essential for T lymphocyte development. Since the molecular mechanism for the control of CD4 gene expression during T cell development had not been elucidated, a study of the factors that control CD4 gene expression may lead to further. Toward these goals, we have made a series of recombinant DNA constructs to define the <em>cis</em>-acting transcriptional control elements in the murine CD4 locus that control CD4 gene expression during T cell development. In this study, we have identified multiple <em>cis</em>-acting control elements, which are critical for regulating the expression of the murine CD4 gene. Two intronic enhancers, which are located in a 122 bp <em>Alu</em>l-<em>Alu</em>l fragment 5' of the first intron and a 174 bp <em>Pst</em>l-<em>Sal</em>I fragment 3' of the first intron, act in an orientation- and position-independent manner in both CD4⁺ and CD4^- T cells. DNase I footprint analyses revealed the location of potential transcription factor-binding sequences in the protected regions include GATA-1, Elf-1, and AP-1 for the 5' intronic enhancer, and PU.1, IRF-1, and GATA-1 for the 3' intronic enhancer. Among them, Elf-1 and PU.1, members of the Ets protein family, and AP-1 have been implicated in the regulation of T cell-specific gene expression. An intronic promoter is located in the 138 bp fragment within the first intron. This promoter is activated preferentially in the CD4⁺CD8^- T cells. Primer extension analysis indicates that the transcription initiation is located 107 bp upstream from the ATG site. A silencer element is loctaed in a 250 bp fragment corresponding to DH8, has a negative effect on the CD4 promoter activation in an orientation- and position-independent way in T cells. In summary, the molecular mechanisms, which control CD4 gene expression during T cell development, are complex and the result of coordinate interplay of multiple transcriptional control elements.</p>

Name thesis:degree_name

Doctor of Philosophy (Medical Science)

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Biochemistry

Year

2000

Author dc:creator

• Deng, Zhong

Contributors dc:contributor

• Aladar A. Szalay
• Thomas Linkhart
• Charles W. Slattery
• Donna Strong
• R. Bruce Wilcox

• Biochemistry
• Genetic Structures
• Laboratory and Basic Science Research
• Antigens -- immunology; Receptors, Antigen -- immunology; Antigens, CD4; Gene Expression Regulation, Developmental

Statement dc:rights

• This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.

Language dc:language

English

Repository record dc:identifier

https://scholarsrepository.llu.edu/etd/1411

OAI identifier oai:identifier

oai:scholarsrepository.llu.edu:etd-2183