Siegfried W. de Laat

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Receptor protein-tyrosine phosphatase alpha (RPTP alpha) is a transmembrane member of the family of protein-tyrosine phosphatases (PTPs) that has been implicated in neuronal differentiation in vitro. Here we demonstrate that RPTP alpha is differentially expressed during mouse embryogenesis in a spatio-temporal manner. RPTP alpha expression was detectable in(More)
Growth factor-induced stress fiber formation involves signal transduction through Rac and Rho proteins and production of leukotrienes from arachidonic acid metabolism. In exploring the relationship between these pathways, we found that Rac is essential for EGF-induced arachidonic acid production and subsequent generation of leukotrienes and that Rac V12, a(More)
A number of studies suggest a role for PTHrP and the classical PTH/PTHrP receptor (type I) in one of the first differentiation processes in mouse embryogenesis, i.e. the formation of parietal endoderm (PE). We previously reported that although in type I receptor (-/-) embryos PE formation seemed normal, the embryos were smaller from at least day 9.5 p.c.(More)
The TPA-inducible transcription factor AP-1, consisting of homo- or hetero-dimers of members of the Jun- and Fos-families, regulates transcription of a wide variety of genes containing the TPA response element (TRE). In P19 embryonal carcinoma (EC) cells, Jun D is the only component of AP-1 expressed, while in these cells until now none of the members of(More)
Goosecoid is a homeobox gene that is expressed as an immediate early response to mesoderm induction by activin. We have investigated the induction of the zebrafish goosecoid promoter by the mesoderm inducing factors activin and basic fibroblast growth factor (bFGF) in dissociated zebrafish blastula cells, as well as by different wnts in intact embryos.(More)
Heat shock at 42°caused a rapid inhibition of protein synthesis in Reuber H35 hepatoma cells. Inhibition was maximal within 5 min after the temperature was increased. After heat shock at 42°for 30 min, protein synthesis was restored in 4 to 5 hr. Heat shock did not inhibit amino acid transport or cause a decrease of cellular amino acid pools, excluding a(More)
Cellular transformation of normal rat kidney (NRK) cells by simian sarcoma virus (SSV) results in a complete loss of the cellular requirement of externally added polypeptide growth factors for proliferation. More over, SSV-transformed NRK cells have a strongly reduced ability to bind both external platelet-derived growth factor and epidermal growth factor,(More)
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