Quantification of endogenous and exogenous protein expressions of Na,K-ATPase with super-resolution PALM/STORM imaging.

Bernhem K, Blom H, Brismar H

PLoS ONE 13 (4) e0195825 [2018-04-25; online 2018-04-25]

Transient transfection of fluorescent fusion proteins is a key enabling technology in fluorescent microscopy to spatio-temporally map cellular protein distributions. Transient transfection of proteins may however bypass normal regulation of expression, leading to overexpression artefacts like misallocations and excess amounts. In this study we investigate the use of STORM and PALM microscopy to quantitatively monitor endogenous and exogenous protein expression. Through incorporation of an N-terminal hemagglutinin epitope to a mMaple3 fused Na,K-ATPase (α1 isoform), we analyze the spatial and quantitative changes of plasma membrane Na,K-ATPase localization during competitive transient expression. Quantification of plasma membrane protein density revealed a time dependent increase of Na,K-ATPase, but no increase in size of protein clusters. Results show that after 41h transfection, the total plasma membrane density of Na,K-ATPase increased by 63% while the endogenous contribution was reduced by 16%.

Bioinformatics Support for Computational Resources [Service]

Integrated Microscopy Technologies Stockholm [Technology development]

PubMed 29694368

DOI 10.1371/journal.pone.0195825

Crossref 10.1371/journal.pone.0195825

pii: PONE-D-17-24779
pmc: PMC5918999
Dryad: 10.5061/dryad.kc42g

Publications 9.5.0