Extracellular signal-regulated activation of Rap1 fails to interfere in Ras effector signalling.

The small GTPase Rap1 has been implicated in both negative and positive control of Ras-mediated signalling events. We have investigated which extracellular signals can activate Rap1 and whether this activation leads to a modulation of Ras effector signalling, i.e.

Discordance of p53 status in matched primary tumours and metastases in head and neck squamous cell carcinoma patients.

To study the use of p53 as a diagnostic tool in head and neck squamous cell carcinoma (HNSCC), we analysed 15 primary tumours (PT) and matched lymph node metastases (LNM) for overexpression and mutations of p53. The primary goal was to study whether differentiation between primary and metastatic disease through their p53 status would be possible. Immunohistochemistry for p53 protein (antibody BP 53-12-1) was performed.

The N-terminal region of the adenovirus type 5 E1A proteins can repress expression of cellular genes via two distinct but overlapping domains.

The transforming E1A 12S and E1A 13S proteins of human adenovirus type 5 (Ad5) contain two and three conserved regions, respectively. In the present study, the contribution of sequences in the nonconserved N-terminal region of the E1A proteins to morphological transformation and to down-regulation of a number of mitogen-inducible genes was investigated. As described previously, transformation of NRK cells (an established normal rat kidney cell line) results in denser cell growth and a cuboidal cellular morphology.

The human low affinity immunoglobulin G Fc receptor IIC gene is a result of an unequal crossover event.

We have isolated and characterized three genes coding for hFc gamma RIIA, IIB, and IIC. Each gene spans approximately 15-19 kilobases of DNA and consists of eight exons. Two exons encode the 5'-untranslated region and signal peptides, two exons code for homologous Ig-like extracellular domains, a single exon encodes the transmembrane spanning region, and three exons encode the cytoplasmic domains and 3'-untranslated regions.