Subcellular protein turnover in human neural progenitor cells revealed by correlative electron microscopy and nanoscale secondary ion mass spectrometry imaging.

Lork AA, Rabasco S, Ernst C, du Toit A, Rizzoli SO, Phan NTN

Chem. Sci. 15 (9) 3311-3322 [2024-02-28; online 2024-01-29]

Protein turnover is a critical process for accurate cellular function, in which damaged proteins in the cells are gradually replaced with newly synthesized ones. Many previous studies on cellular protein turnover have used stable isotopic labelling by amino acids in cell culture (SILAC), followed by proteomic bulk analysis. However, this approach does not take into account the heterogeneity observed at the single-cell and subcellular levels. To address this, we investigated the protein turnover of neural progenitor cells at the subcellular resolution, using correlative TEM and NanoSIMS imaging, relying on a pulse-chase analysis of isotopically-labelled protein precusors. Cellular protein turnover was found significantly heterogenous across individual organelles, which indicates a possible relation between protein turnover and subcellular activity. In addition, different isotopically-labelled amino acids provided different turnover patterns, in spite of all being protein precursors, suggesting that they undergo distinct protein synthesis and metabolic pathways at the subcellular level.

Integrated Microscopy Technologies Gothenburg [Service]

PubMed 38425528

DOI 10.1039/d3sc05629e

Crossref 10.1039/d3sc05629e

pmc: PMC10901485
pii: d3sc05629e