[Show abstract][Hide abstract]ABSTRACT: Small ubiquitin-related modifier (SUMO) is a type I ubiquitin-like protein family member and is covalently attached to various target proteins. Through this post-translational modification, SUMO plays important roles in various cellular events. Here, we show that SUMO is secreted from cultured cells in an endoplasmic reticulum (ER)/Golgi-independent manner and that this secretion occurs without covalent binding to target proteins or chain formation. Overexpression experiments using C-terminally truncated mutants of SUMO revealed that the secretion requires the C-terminal sequence. Recombinant SUMO-3 protein was capable of binding to and promoting the proliferation of cultured cells. Thus, we propose that SUMO functions as a cytokine-like molecule extracellularly.
Article · Jun 2008 · Biological & Pharmaceutical Bulletin
[Show abstract][Hide abstract]ABSTRACT: A new inhibitor of p53-HDM2 interaction was isolated from a culture of marine-derived fungus, Arthrinium sp. The structure was identified to be (-)-hexylitaconic acid (1) by spectroscopic analysis. The inhibition of p53-HDM2 binding was tested by the ELISA method, and 1 inhibited the binding with an IC50 value of 50 mu g/mL. Although a number of synthetic inhibitors of p53-HDM2 interaction have been reported so far, 1 is the second inhibitor isolated from natural resources. (c) 2005 Elsevier Ltd. All rights reserved.
Article · Feb 2006 · Bioorganic & Medicinal Chemistry Letters