Human Dopaminergic Neurons Lacking PINK1 Exhibit Disrupted Dopamine Metabolism Related to Vitamin B6 Co-Factors.

PINK1 loss-of-function mutations cause early onset Parkinson disease. PINK1-Parkin mediated mitophagy has been well studied, but the relevance of the endogenous process in the brain is debated. Here, the absence of PINK1 in human dopaminergic neurons inhibits ionophore-induced mitophagy and reduces mitochondrial membrane potential.

Absolute Quantification of Endogenous Ras Isoform Abundance.

Ras proteins are important signalling hubs situated near the top of networks controlling cell proliferation, differentiation and survival. Three almost identical isoforms, HRAS, KRAS and NRAS, are ubiquitously expressed yet have differing biological and oncogenic properties. In order to help understand the relative biological contributions of each isoform we have optimised a quantitative proteomics method for accurately measuring Ras isoform protein copy number per cell.

Differential reprogramming of isogenic colorectal cancer cells by distinct activating KRAS mutations.

Oncogenic mutations of Ras at codons 12, 13, or 61, that render the protein constitutively active, are found in ∼ 16% of all cancer cases. Among the three major Ras isoforms, KRAS is the most frequently mutated isoform in cancer. Each Ras isoform and tumor type displays a distinct pattern of codon-specific mutations.

The role of palmitoylation in regulating Ras localization and function.

Ras GTPases are important regulators of pathways controlling proliferation, differentiation and transformation. Three ubiquitously expressed almost identical Ras genes are not functionally redundant; this has been attributed to their distinctive trafficking and localization profiles. A palmitoylation cycle controls the correct compartmentalization of H-Ras and N-Ras.

PROTEINCHALLENGE: crowd sourcing in proteomics analysis and software development.

In large-scale proteomics studies there is a temptation, after months of experimental work, to plug resulting data into a convenient-if poorly implemented-set of tools, which may neither do the data justice nor help answer the scientific question. In this paper we have captured key concerns, including arguments for community-wide open source software development and "big data" compatible solutions for the future. For the meantime, we have laid out ten top tips for data processing.

Miniaturisation of a high throughput screening assay comparing air displacement and capillary-based nanolitre transfer technologies.

The miniaturisation of high-throughput screening (HTS) assays has been a widely debated and researched strategy with the aims of reducing screening costs and increasing speed while not compromising data quality. In this context, liquid handling technologies continue to be improved. A new and promising development is the emergence of nanolitre dispensers, which are capable of direct compound transfer to assay microplates.