Figure 1

Distinguishing between rapidly and slowly aggregating proteins using GFP fusion. A C-terminally fused GFP tag reports on the relative time of aggregation across proteins. Nascent polypeptides with very high aggregation rates form anomalous intermolecular interactions before the GFP chromophore is committed to form¹⁷ and therefore the fused GFP tag would show no fluorescence, yielding dark aggregates (lower pathway, black ball). Note that this route of aggregation likely occurs before the protein is folded, possibly as early as translation. Proteins that aggregate after the GFP chromophore is committed to form would result in fluorescent aggregates (upper pathway) (de Groot & Ventura, 2006). These proteins aggregate relatively slowly, after being fully synthesized (i.e. post-translationally).