Enter Your Search:
Results 1-2 (2)
Go to page number:
Select a Filter Below
Blood Cancer Journal (1)
Nucleic Acids Research (1)
Slany, R K (2)
Dassé, E (1)
Del Pozzo, W (1)
Dumon, S (1)
Frampton, J (1)
Kersten, H (1)
O'Neill, L P (1)
Volpe, G (1)
Walton, D S (1)
Wilson, N (1)
Year of Publication
Did you mean:
author:("slant, R K")
Distinct regulation of c-myb gene expression by HoxA9, Meis1 and Pbx proteins in normal hematopoietic progenitors and transformed myeloid cells
Walton, D S
Del Pozzo, W
O'Neill, L P
Blood Cancer Journal
The proto-oncogenic protein c-Myb is an essential regulator of hematopoiesis and is frequently deregulated in hematological diseases such as lymphoma and leukemia. To gain insight into the mechanisms underlying the aberrant expression of c-Myb in myeloid leukemia, we analyzed and compared c-myb gene transcriptional regulation using two cell lines modeling normal hematopoietic progenitor cells (HPCs) and transformed myelomonocytic blasts. We report that the transcription factors HoxA9, Meis1, Pbx1 and Pbx2 bind in vivo to the c-myb locus and maintain its expression through different mechanisms in HPCs and leukemic cells. Our analysis also points to a critical role for Pbx2 in deregulating c-myb expression in murine myeloid cells cotransformed by the cooperative activity of HoxA9 and Meis1. This effect is associated with an intronic positioning of epigenetic marks and RNA polymerase II binding in the orthologous region of a previously described alternative promoter for c-myb. Taken together, our results could provide a first hint to explain the abnormal expression of c-myb in leukemic cells.
c-myb; hematopoietic progenitors; myeloid leukemia; Hox and TALE proteins
The promoter of the tgt/sec operon in Escherichia coli is preceded by an upstream activation sequence that contains a high affinity FIS binding site.
Nucleic Acids Research
The tgt/sec operon in E. coli consists of five genes: queA, tgt, ORF12, secD, and secF. QueA and Tgt participate in the biosynthesis of the hypermodified t-RNA nucleoside Queuosine, whereas SecD and SecF are involved in protein secretion. Examination of the promoter region of the operon showed structural similarity to promoter regions of the rrn-operons. An upstream activation sequence (UAS) containing a potential binding site for the factor of inversion stimulation (FIS) was found. Gel retardation assays and DNaseI footprinting indicated, that FIS binds specifically and with high affinity to a site centred at position -58. Binding of FIS caused bending of the DNA, as deduced from circular permutation analysis. Various 5' deletion mutants of the promoter region were constructed and fused to a lacZ reporter gene to determine the influence of the UAS element on the promoter strength. An approximately two-fold activation of the promoter by the UAS element was observed.
Results 1-2 (2)
Go to page number:
Remove citation from clipboard
Add citation to clipboard
This will clear all selections from your clipboard. Do you wish proceed?
Clipboard is full! Please remove an item and try again.
PubMed Central Canada is a service of the
Canadian Institutes of Health Research
(CIHR) working in partnership with the National Research Council's
Canada Institute for Scientific and Technical Information
in cooperation with the
National Center for Biotechnology Information
U.S. National Library of Medicine
(NCBI/NLM). It includes content provided to the
PubMed Central International archive
by participating publishers.