In contrast, the RING1 domain mutant FLAG-Parkin(C289G) was expressed at slightly lower levels than Parkin WT) and was strongly aggregation-prone (Fig. 1 and Supplementary Material, Fig. S1B).
To validate that the artificial, oligomeric mutants A56P and TP indeed showed strongly impaired aggregation, we assessed the generation of aggregated αSynuclein by probing its resistance against PK digestion.
We could confirm that nature uses negative design principles to avoid the self-assembly of aggregation-prone regions in globular cytosolic proteins as well as the strongly decreased aggregation propensity of cytosolic IUPs, as previously proposed by Serrano and Chiti groups by analyzing different virtual proteomes [21], [22], [27].
This peptide strongly inhibited aggregation, including Als5pWT-expressing S. cerevisiae and C. albicans (Figure 4C vs. 4S and 4D vs. 4T).
Profilin strongly inhibits aggregation of ARN127 and Htt exon 1 in cells [29], and decreases polyglutamine-mediated toxicity in Drosophila [22].
We wondered whether the strong hydrophobic character within the first 10 amino acids is responsible for the strongly enhanced aggregation of Mca1451.
Along similar lines, Liu and coworkers recently engineered supercharged versions of sfGFP whose net charge was altered by as much as +48 charge units and, as a result, remained soluble even when exposed to conditions that strongly favored aggregation [12].
The authors report the seemingly paradoxical observation that incubation of cells at an elevated temperature of 40°C strongly reduces aggregation of the model substrate Sup35 in its prion form [ PSI + ]Weak.
Diffuse plaques contained strongly stained aggregations of Aβ peptide.
Their molecular features, a large and charged saccharidic headgroup connected to a sticky and extended ceramide double tail, strongly dictate their aggregation properties and place ganglioside aggregates at the borderline between the curved world and the flatland.
The structures of the mature amyloid fibrils, the presence of oligomeric intermediates in electron micrographs at early incubation times, and the sensitivity to HTTNT inhibition of aggregation strongly suggest that these full-length HTT exon1 analogues aggregate by the same two-step mechanism deduced for C-terminally truncated HTT exon1 peptides.
