Quick Delivery of Aldehyde Dehydrogenase into Yeast Vacuoles by QRPL Peptide Sequence on Carboxypeptidase Y

Background The signal peptide sequence is known to increase transport efficiency to organelles in eukaryotic cells. In this study, we focus on the signal peptide of the vacuolar protein for vacuolar targeting. Results The signal peptide sequence QRPL of carboxypeptidase Y (CPY), a vacuolar protein, was inserted inside the green fluorescent protein (GFP) that does not locate in vacuole for vacuolar targeting. The protein location was then confirmed by confocal microscopy. Fascinatingly, the green fluorescent protein that contains QRPL inside the sequence could be expressed faster than its natural form (within 1 hour after induction). In addition, aldehyde dehydrogenase 6 (ALD6), a cytosolic protein has engineered the sequence with QRPL to be transported to the vacuole. The aldehyde removal activity of ALD6 protein in the recombinant yeast was then analyzed by measuring the luminescent intensity in Vibrio fischeri . Conclusions In summary, the signal peptide QRPL could be used not only to transport target proteins accurately to vacuole but also to improve the protein activity, as well as to shorten the induction time.