Transcriptional Control of D-beta-2

Show simple item record

dc.contributor.advisor Linda Hanley-Bowdoin, Committee Member en_US
dc.contributor.advisor Michael L. Sikes, Committee Chair en_US
dc.contributor.advisor Scott M. Laster, Committee Co-Chair en_US
dc.contributor.advisor James W. Brown, Committee Member en_US McMillan, Ruth Erica en_US 2010-04-02T18:27:33Z 2010-04-02T18:27:33Z 2008-12-05 en_US
dc.identifier.other etd-10312007-121807 en_US
dc.description.abstract ABSTRACT McMILLAN, RUTH ERICA. Transcriptional Control of D?2. (Under the direction of Michael L. Sikes). The immune system?s response to invading pathogens depends on the ability of T and B-lymphocytes to generate a diverse repertoire of antigen receptors. This diversity is created during lymphocyte development by somatic recombination of variable (V), diversity (D) and joining (J) gene segments. Transcription of unrearranged gene segments precedes their recombination. Given the correlation of transcription and recombination, it has been suggested that enhancers and promoters within each locus may regulate the recombinational accessibility of nearby gene segments. For example, in developing T cells, two stages of recombination (first D to J, then V to DJ) are seen in the T cell receptor beta gene (TCR?). Both steps require the TCR? enhancer, E?, while a promoter associated with the first D segment (PD?1) only controls its recombination. In mutant cells that lack PD?1, the second D? rearranges normally. To investigate the regulation of D?2 recombination, we have characterized the transcriptional profile of DJC?2 gene cassette and identified separate promoter activities positioned 5? and 3? of D?2. The relatively simple downstream promoter (3?PD?2) contains no discernable initiator or TATA elements and is located 400 bases downstream of D?2 and is driven by two NFkB binding sites. Ribonuclease protection assay and 5? RACE PCR revealed diffused transcription start sites throughout the entire 150 bp promoter region. Transcription from 3?PD?2 occurs only when the TCR? locus is in its germline configuration. In-vivo germline transcription of the upstream promoter (5?PD?2) is detected in DNA with D?J?2 joints. When luciferase reporter plasmid bearing E? and sequential truncations of the DJ?2 sequence was transiently transfected into a RAG1 deficient cell line in-vitro, transcription from 5?PD?2 was detected when a 290 bp region immediately downstream of D?2 was deleted. Therefore, germline transcription from 5?PD?2 is held in repression while 3?PD?2 is active. Our report indicates that 3?PD?2 is positioned downstream of its associated D segment; a position that does not efficiently promote recombination. We hypothesize that this unique positioning plays an essential role in delaying D?2 recombination, thereby providing the locus with a second recombination opportunity should the recombination with the upstream D?1 fail. en_US
dc.rights I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dis sertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. en_US
dc.subject D-beta-2 en_US
dc.subject V(D)J recombination en_US
dc.subject TCR? en_US
dc.subject promoter en_US
dc.title Transcriptional Control of D-beta-2 en_US PhD en_US dissertation en_US Microbiology en_US

Files in this item

Files Size Format View
etd.pdf 3.412Mb PDF View/Open

This item appears in the following Collection(s)

Show simple item record