scholarly journals Meis Transcription Factor in Axial Development

2019 ◽  
Author(s):  
Alejandra Cristina Lopez Delgado
Development ◽  
1999 ◽  
Vol 126 (24) ◽  
pp. 5621-5634 ◽  
Author(s):  
M. Watanabe ◽  
M. Whitman

We have examined the role of the maternally encoded transcription factor FAST-1 in the establishment of the mesodermal transcriptional program in Xenopus embryos. FAST-1 has been shown to associate with Smad2 and Smad4, transducers of TGFbeta superfamily signals, in response to stimulation by several TGFbeta superfamily ligands. The FAST-1/Smad2/Smad4 complex binds and activates a 50 bp activin responsive element identified in the promoter of the meso-endodermal marker Mix.2. We have now used three complementary approaches to demonstrate that FAST-1 is a central regulator of mesoderm induction by ectopic TGFbeta superfamily ligands and during endogenous patterning: ectopic expression of mutationally activated FAST-1, ectopic expression of dominant inhibitory FAST-1, and injection of a blocking antibody specific for FAST-1. Expression of constitutively transcriptionally active FAST-1 fusion protein (FAST-VP16(A)) in prospective ectoderm can directly induce the same set of general and dorsal mesodermal genes, as well as some endodermal genes, as are induced by activin or Vg1. In intact embryos, this construct can induce secondary axes similar to those induced by activin or Vg1. Conversely, expression of a FAST-1-repressor fusion (FAST-En(R)) in prospective ectoderm blocks induction of mesodermal genes by activin, while expression of FAST-En(R) in intact embryos prevents general/dorsal mesodermal gene expression and axial development. Injection of a blocking antibody specific for FAST-1 prevents induction of mesodermal response genes by activin or Vg1, but not by FGF. In intact embryos, this antibody can prevent the expression of early mesodermal markers and inhibit axis formation, demonstrating that FAST-1 is a necessary component of the first steps in the specification of mesoderm.


Author(s):  
David P. Bazett-Jones ◽  
Mark L. Brown

A multisubunit RNA polymerase enzyme is ultimately responsible for transcription initiation and elongation of RNA, but recognition of the proper start site by the enzyme is regulated by general, temporal and gene-specific trans-factors interacting at promoter and enhancer DNA sequences. To understand the molecular mechanisms which precisely regulate the transcription initiation event, it is crucial to elucidate the structure of the transcription factor/DNA complexes involved. Electron spectroscopic imaging (ESI) provides the opportunity to visualize individual DNA molecules. Enhancement of DNA contrast with ESI is accomplished by imaging with electrons that have interacted with inner shell electrons of phosphorus in the DNA backbone. Phosphorus detection at this intermediately high level of resolution (≈lnm) permits selective imaging of the DNA, to determine whether the protein factors compact, bend or wrap the DNA. Simultaneously, mass analysis and phosphorus content can be measured quantitatively, using adjacent DNA or tobacco mosaic virus (TMV) as mass and phosphorus standards. These two parameters provide stoichiometric information relating the ratios of protein:DNA content.


Nephrology ◽  
2000 ◽  
Vol 5 (3) ◽  
pp. A92-A92
Author(s):  
Takazoe K ◽  
Foti R ◽  
Hurst La ◽  
Atkins Rc ◽  
Nikolic‐Paterson DJ.

2001 ◽  
Vol 120 (5) ◽  
pp. A31-A31
Author(s):  
H KATAOKA ◽  
T JOH ◽  
T OHSHIMA ◽  
Y ITOH ◽  
K SENOO ◽  
...  

2008 ◽  
Vol 7 ◽  
pp. 109-109
Author(s):  
R BRECKENRIDGE ◽  
Z ZUBERI ◽  
L FELKIN ◽  
E BIRKS ◽  
P BARTON ◽  
...  

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