Himatanthus sucuuba (Spruce ex Müll. Arg.) Woodson (Apocynaceae) is used in the Amazonian region for the treatment of inflammatory diseases [1]. The bark of this medicinal plant was phytochemically investigated guided by an LPS/TNF stimulated assay measuring E-selectin and IL-8. Out of bioactive fractions 11 constituents were isolated and identified by MS and 1D and 2D NMR experiments as iridoids (plumericin, plumieridin, allamandicin, and the new natural product (2'R,3R,4R,4aS,7aR)-methyl 3-hydroxy-4'-((S)-1-hydroxyethyl)-5'-oxo-3,4,4a,7a-tetrahydro-1H,5'H-spiro[cyclopenta[c]pyran-7,2'-furan]-4-carboxylate), flavonoids (biochanin A, dihydrobiochanin A, dalbergioidin, naringenin, ferreirin, and dihydrocajanin), and the lignan pinoresinol. Except for plumericin and pinoresinol this is the first time these compounds are reported to be isolated from Himatanthus sucuuba. The structure of the new iridoid was determined using X-ray crystallography. Interestingly, NMR experiments showed the presence of two compounds indicating stereochemical conversion.

. Small HERC proteins are defined by the presence of one RCC1-like domain and a HECT domain. Having evolved out of one common ancestor, the four members of the family exhibit a high degree of homology in genomic organization and amino acid sequence, thus it seems possible that they might accomplish similar functions. Here we show that small HERC proteins interact with each other and localize to the same cellular structures, which we identify as late endosomes and lysosomes. We demonstrate interaction of HERC3 with the ubiquitin-like proteins hPLIC-1 and hPLIC-2 and we establish interaction of HERC5 with the metastasis suppressor Nm23B. While hPLIC proteins are not ubiquitinated by HERC3, HERC5 plays an important role in ubiquitination of Nm23B. In summary, although small HERC proteins are highly homologous showing the same subcellular distribution, they undergo different molecular interactions.

Defects in activity and/or antigen levels of ADAMTS-13, the von Willebrand Factor (vWF) cleaving protease, are viewed as the main cause inducing the microvascular thrombotic disorder TTP (thrombotic thrombocytopenic purpura) that is in more than 90% of cases fatal if not treated early and appropriately. Malfunction of ADAMTS-13 with respect to cleave multimeric vWF can be caused by auto-antibodies directed against ADAMTS-13, by decreased presence of ADAMTS-13 in the circulation or by defective activity of ADAMTS-13. Therefore rapid and reliable diagnosis of ADAMTS-13 parameters is a clinical need. We present here an assay for quantification of ADAMTS-13 antigen levels. The assay is a regular double sandwich ELISA employing a monoclonal antibody for capturing ADAMTS-13 from the sample by binding to the CUB domains. The bound ADAMTS-13 is detected by a polyclonal antibody conjugate. The sensitivity of the assay is below 10% of the normal antigen level. In normal samples a wide range (50% to 200%) of the mean level was observed. In idiopathic TTP plasmas also a wide range of antigen levels was observed but with a slighltly lower mean value than in normal samples. Samples from hereditary TTP mostly showed lower antigen levels than normal samples. Thus we could show that this assay provides a useful tool for measuring ADAMTS-13 antigen levels. In combination with our activity assay, which is being developed in parallel, it will be possible to establish ratios of activity and antigen which could provide more insight into the mechanisms of ADAMTS-13 deficiencies than the individual values for antigen and activity.

We describe here the identification and initial characterization of a novel human gene termed IKIP (I kappa B kinase interacting protein) that is located on chromosome 12 in close proximity to APAF1 (apoptotic protease-activating factor-1). IKIP and APAF1 share a common 488 bp promoter from which the two genes are transcribed in opposite directions. Three IKIP transcripts are generated by differential splicing and alternative exon usage that do not show significant homology to other genes in the databases. Similar to APAF1, expression of IKIP is enhanced by X-irradiation, and both genes are dependent on p53. Moreover, IKIP promotes apoptosis when transfected into endothelial cells. We conclude that IKIP is a novel p53 target gene with proapoptotic function.