Analysis of Transcription Regulation Complex of An Epithelial Cell-Specific EBV Promoter ED-L1E In NPC Cells

• Main Authors: CHEN HSIN-HSU, 陳信旭
• Other Authors: 張玉生
• Format: Others
• Language: en_US
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/32735696561350747458

碩士 === 長庚大學 === 基礎醫學研究所 === 95 === Expression of LMP1 gene can be initiated from two promoters: ED-L1 (EBV genome nt 169571- nt 169498) and ED-L1E (nt 170159- nt 170132). Two transcripts with molecular sizes of 2.8 kb and 3.5 kb are transcripted by ED-L1 and ED-L1E, respectively. ED-L1 is used in both B lymphocytes and epithelial cells, whereas ED-L1E is preferentially used in epithelial cells. Thus, we hypothesize that the transcription regulation complex that determines the usage of ED-L1E can be specifically formed in epithelial cells. Previous study suggests that ED-L1E can be regulated by cellular transcription factors Sp1 and Sp3 which are ubiquitously expressed in epithelial cells. However, it is not clear what other cellular factors may be involved in forming this transcription complex that can regulate ED-L1E activity. Using the ED-L1E DNA to incubate with the nuclear extracts of NPC-TW02 cells, the proteins potentially contained in the complex were pulled down. After analyzed on 8-15％ gradient SDS-PAGE, followed by identified through MALDI-TOF analysis, Helicase like transcription factor (HLTF) was identified. By EMSA study, I further showed that probe 1 (nt 170165 - nt 170135) of ED-L1E could form a complex with nuclear extracts. This DNA-protein complex had no obvious supershift, when anti-Sp1, anti-HLTF or both antibodies were added. Further validation of the data is merited.