|
|
||||||||

Institut für Klinische und Molekulare Virologie der Universität Erlangen-Nürnberg, D-8520 Erlangen, F.R.G.
The major enhancer, extending from nucleotides -530 to -120 upstream of the transcription initiation site of immediate early (IE) genes 1 and 2 in human cytomegalovirus (HCMV), contains four groups of repeated sequence motifs that consist of 17, 18, 19 or 21 bp, respectively. One of these elements, the 19 bp repeat, is a symmetrical palindrome that is also part of IE regulatory sequences of other cytomegalovirus-type herpesviruses, but not of unrelated members of the herpesvirus group. Synthetic oligonucleotides representing the 19 bp repeat unit strongly reduced the activity of the IE1/2 enhancer/promoter in cotransfection assays after transient expression. The HCMV enhancer can substitute for the 72 bp repeats of simian virus 40 (SV40). Replication-competent deletion mutants of SV40/HCMV enhancer recombinants were constructed that contained a single palindromic 19 bp repeat with a central cleavage site for AhaII. If deletions were introduced into the single remaining 19 bp repeat most of the mutant viruses were still replication-competent in CV-1 monkey kidney cells. Insertion of two nucleotides into the single AhaII site did not significantly alter transient SV40 T antigen expression. Deletion of four nucleotides or more from the single 19 bp palindrome reduced the stimulation of T antigen synthesis by the HCMV enhancer/SV40 promoter unit down to about 50%. More extended deletions (28 to 80 bp) did not further reduce T antigen expression. All mutants without an intact 19 bp repeat contained the 18 bp and/or the 21 bp sequence motif. DNase I footprinting and gel retardation assays indicated sequence-specific protein binding by the 19 bp palindrome. Altered palindromes, correlating with reduced enhancer activity, lost most of their protein-binding properties. Thus, the 19 bp repeat element is one of several protein-binding sites that contribute to enhancer strength. However, the 19 bp sequence motif can be deleted entirely to leave reduced activity. The HCMV IE1/2 upstream sequence appears to be the perfect model of an enhancer as a complex of multiple binding sites for trans-activating proteins in a modular fashion.
Keywords: cytomegalovirus, human, enhancer, immediate early genes
Present address: Boehringer Mannheim GmbH Biochemica, Production and Research Plant, Department of Genetics, D-8122 Penzberg, F.R.G.
Received 10 May 1988;
accepted 19 September 1988.
This article has been cited by other articles:
![]() |
P. Shen, G. Niu, M. Yao, H. Wang, and J. Fei Studying on the 19-bp Palindrome Repeats in Human Cytomegalovirus Immediate Early Enhancer/Promoter Reveals their Diversity in Function for the Promoter Activity J. Biochem., July 1, 2007; 142(1): 25 - 31. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Naderi, J. Y.J. Wang, T.-T. Chen, K. B. Gutzkow, and H. K. Blomhoff cAMP-mediated Inhibition of DNA Replication and S Phase Progression: Involvement of Rb, p21Cip1, and PCNA Mol. Biol. Cell, March 1, 2005; 16(3): 1527 - 1542. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Schierling, T. Stamminger, T. Mertens, and M. Winkler Human Cytomegalovirus Tegument Proteins ppUL82 (pp71) and ppUL35 Interact and Cooperatively Activate the Major Immediate-Early Enhancer J. Virol., September 1, 2004; 78(17): 9512 - 9523. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Kadener, J. P. Fededa, M. Rosbash, and A. R. Kornblihtt Regulation of alternative splicing by a transcriptional enhancer through RNA pol II elongation PNAS, June 11, 2002; 99(12): 8185 - 8190. [Abstract] [Full Text] [PDF] |
||||
![]() |
Q. Ning, M. Liu, P. Kongkham, M. M. C. Lai, P. A. Marsden, J. Tseng, B. Pereira, M. Belyavskyi, J. Leibowitz, M. J. Phillips, et al. The Nucleocapsid Protein of Murine Hepatitis Virus Type 3 Induces Transcription of the Novel fgl2 Prothrombinase Gene J. Biol. Chem., April 9, 1999; 274(15): 9930 - 9936. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Staak, S. Prosch, J. Stein, C. Priemer, R. Ewert, W.-D. Docke, D. H. Kruger, H. D. Volk, and P. Reinke Pentoxifylline Promotes Replication of Human Cytomegalovirus In Vivo and In Vitro Blood, May 15, 1997; 89(10): 3682 - 3690. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Prosch, A.-K. Heine, H.-D. Volk, and D. H. Kruger CCAAT/Enhancer-binding Proteins alpha and beta Negatively Influence the Capacity of Tumor Necrosis Factor alpha to Up-regulate the Human Cytomegalovirus IE1/2 Enhancer/Promoter by Nuclear Factor kappa B during Monocyte Differentiation J. Biol. Chem., October 26, 2001; 276(44): 40712 - 40720. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. G. Wheeler and E. Cooper Depolarization Strongly Induces Human Cytomegalovirus Major Immediate-Early Promoter/Enhancer Activity in Neurons J. Biol. Chem., August 17, 2001; 276(34): 31978 - 31985. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| INT J SYST EVOL MICROBIOL | MICROBIOLOGY | J GEN VIROL |
| J MED MICROBIOL | ALL SGM JOURNALS | |