Ligand binding reveals a role for heme in translationally-controlled tumor protein dimerization.

ABSTRACT: The translationally-controlled tumor protein (TCTP) is a highly conserved, ubiquitously expressed, abundant protein that is broadly distributed among eukaryotes. Its biological function spans numerous cellular processes ranging from regulation of the cell cycle and microtubule stabilization to cell growth, transformation, and death processes. In this work, we propose a new function for TCTP as a "buffer protein" controlling cellular homeostasis. We demonstrate that binding of hemin to TCTP is mediated by a conserved His-containing motif (His76His77) followed by dimerization, an event that involves ligand-mediated conformational changes and that is necessary to trigger TCTP's cytokine-like activity. Mutation in both His residues to Ala prevents hemin from binding and abrogates oligomerizati

SUBMITTER: Lucas AT 

PROVIDER: S-EPMC4232476 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature