Expression of fluorescently tagged connexins: a novel approach to rescue function of oligomeric DsRed-tagged proteins

A novel, brilliantly red fluorescent protein, DsRed has become available re cently opening up a wide variety of experimental opportunities for double l abeling and fluorescence resonance electron transfer experiments in combina tion with green fluorescent protein (GFP). Unlike in the case of GFP, prote ins tagged,vith DsRed were often found to aggregate within the cell. Here w e report a simple method that allows rescuing the function of an oligomeric protein tagged with DsRed, We demonstrate the feasibility of this approach on the subunit proteins of an oligomeric membrane channel, gap junction co nnexins, Additionally, DsRed fluorescence was easily detected 12-16 h post transfection, much earlier than previously reported, and could readily be d ifferentiated from co-expressed GFP, Thus, this approach can eliminate the major drawbacks of this highly attractive autofluorescent protein. (C) 2001 Federation of European Biochemical Societies. Published by Elsevier Scienc e B.V. All rights reserved.