Chaperone protein involved in transmembrane transport of iron

In this study, we have identified poly(rC)-binding protein 2 (PCBP2) as a DMT1 binding protein. The N-terminal cytoplasmic region of DMT1 was the binding domain for PCBP2. An interaction between DMT1 and PCBP1, which is known to be a paralog of PCBP2, could not be demonstrated in vivo or in vitro. Iron uptake and subsequent ferritin expression were suppressed by either DMT1 or PCBP2 knockdown. Iron-associated DMT1 could interact with PCBP2 in vitro, while iron-chelated DMT1 could not. These results indicated that ferrous iron imported by DMT1 was transferred directly to PCBP2. Moreover, we demonstrated PCBP2 could bind to ferroportin, which exports ferrous iron out of the cell. These findings suggest that PCBP2 can transfer ferrous iron from DMT1 to appropriate intracellular sites or the ferroportin and could function as an iron chaperone.

Source: BJ Cell - May 23, 2014 Category: Biochemistry Authors: I Yanatori, Y Yasui, M Tabuchi, F Kishi Tags: BJ Cell Source Type: research