Nanoparticles Associate with Intrinsically Disordered RNA-Binding Proteins

Nanoparticles
are capable of penetrating cells, but little is known
about the way they interact with intracellular proteome. Here we show
that inorganic nanoparticles associate with low-complexity, intrinsically
disordered proteins from HeLa cytosolic protein extracts in nondenaturing in vitro nanoparticle pull-down assays. Intrinsic protein
disorder associates with structural mobility, suggesting that side-chain
flexibility plays an important role in the driving of a protein to
nanoparticle absorption. Disordered protein domains are often found
in a diverse group of RNA-binding proteins. Consequently, the nanoparticle-associated
proteomes were enriched in subunits of RNA-processing protein complexes.
In turn, this indicates that within a cell, nanoparticles might interfere
with protein synthesis triggering a range of cellular responses.