Profiling proteins in nutraceutical formulations: characterization of the constituents.

Several nutraceutical preparations containing proteins, amino acids and other small molecules are nowadays present on the market. In this work we propose NMR spectroscopy such as (1)H NMR, (1)H-(1)H TOCSY and DOSY for their constituents characterization, identification and profiling, comparing these results with those obtained by electrophoretic technique such as SDS-PAGE. The (1)H NMR spectroscopy was applied for measurements of the amino acids and other small compounds added from the manufacturer.

p63 threonine phosphorylation signals the interaction with the WW domain of the E3 ligase Itch.

Both in epithelial development as well as in epithelial cancers, the p53 family member p63 plays a crucial role acting as a master transcriptional regulator. P63 steady state protein levels are regulated by the E3 ubiquitin ligase Itch, via a physical interaction between the PPxY consensus sequence (PY motif) of p63 and one of the 4 WW domains of Itch; this substrate recognition process leads to protein-ubiquitylation and p63 proteasomal degradation. The interaction of the WW domains, a highly compact protein-protein binding module, with the short proline-rich sequences is therefore a crucial regulatory event that may offer innovative potential therapeutic opportunity.

Recognition mechanism of p63 by the E3 ligase Itch: novel strategy in the study and inhibition of this interaction.

The HECT-containing E3 ubiquitin ligase Itch mediates the degradation of several proteins, including p63 and p73, involved in cell specification and fate. Itch contains four WW domains, which are essential for recognition on the target substrate, which contains a short proline-rich sequence. Several signaling complexes containing these domains have been associated with human diseases such as muscular dystrophy, Alzheimer's or Huntington's diseases.

Reticulon RTN1-C(CT) peptide: a potential nuclease and inhibitor of histone deacetylase enzymes.

RTN1-C protein is a membrane protein localized in the ER and expressed in the nervous system, and its biological role is not completely clarified. Our previous studies have shown that the C-terminal region of RTN1-C, corresponding to the fragment from residues 186 to 208, was able to bind the nucleic acids and to interact with histone deacetylase (HDAC) enzymes. In the present work the properties of the synthetic RTN1-C(CT) peptide corresponding to this region were studied with relation to its ability to bind the metal ions in its N-terminal region.

Nucleic acid binding of the RTN1-C C-terminal region: toward the functional role of a reticulon protein.

RTN1-C protein is a membrane protein localized in the ER and expressed in the nervous system. Its biological role is still unclear, although interactions of the N-terminal region of RTN1-C with proteins involved in vesicle trafficking have been observed, but the role of the C-terminal region of this family protein remains to be investigated. By a homology analysis of the amino acid sequence, we identified in the C-terminal region of RTN1-C a unique consensus sequence characteristic of H4 histone protein.