Objetivo
The main objective of this proposal is to understand the function of the GATA transcription factors in haematopoiesis, with particular emphasis on development of the erythroid and T cell lineages.
We have made substantial progress on a number of the specific objectives in the original network proposal while a number of other objectives were changed due to developments within the project (eg GATA cooperating factors) or in other laboratories (eg the expression analysis and knockout of GATA2).
- Role of GATA1 in globin gene expression
GATA 1 was implicated as a suppressor of e and g globin gene expression. This has been confirmed for the e-gene (Romeo) and excluded for the g-globin genes (Ottolenghi and Grosveld). YY1 was implied to be involved in both e-and g-gene expression (Anagnou and Romeo). One potential suppressor factor (NF-E3) of the g-globin gene has been shown to play a small but significant role (Ottolenghi and Grosveld). NF-E3 has been purified for sequence analysis and contains two subunits of the Ku antigen (Santoro and Ottolenghi). A second area of the promoter (the -200 region) is under intense study as a result of a newly discovered HPFH (Romeo and Grosveld). Most interestingly it was discovered that overexpression of GATA1 leads to changes in the cell cycle by acting on cyclin E dependent kinase (Romeo and Grosveld). Finally a number of regulatory regions and a novel promoter of the GATA1 gene were defined and the ets family of proteins implied in the regulation of GATA1 (Ottolenghi, Santoro and Romeo).
- `GATA1' associated proteins
A number of proteins have been implicated to act in specific combinations with GATA to provide cell type specific expression. In the case of erythroid cells these proteins bind a G-rich sequence. Two proteins were tested by a knockout in mice and a third is in progress. The absence of EKLF leads to a specific and lethal phenotype in adult erythropoiesis and the gene product plays an important role in the competition between early and late globin genes (Grosveld). The absence of Sp1 also leads to a lethal phenotype, however this appears to be a cell autonomous effect that does not inhibit erythropoiesis (Grosveld).
- Role of GATA3 in vivo
The absence of GATA3 leads to a lethal phenotype in which both the neuronal and haematopoietic system are affected. Haematopoiesis is normal in the embryo, but shows a marked absence of precursor cells in definitive haematopoiesis after a burst of activity on day 11 of development (Grosveld). Rescue and transplantation experiments show that the T cell lineage requires GATA3 for development (Grosveld). In addition a number of regulatory regions in the GATA3 gene were defined (Romeo).
- A number of HPFH deletions were characterized and shown to juxtapose enhancer regions to the 3' side of the g-gene, leading to its derepression in the adult stage of erythropoiesis (Anagnou).
Ámbito científico
Tema(s)
Convocatoria de propuestas
Data not availableRégimen de financiación
CSC - Cost-sharing contractsCoordinador
3000 DR Rotterdam
Países Bajos