FBXL4 suppresses mitophagy by restricting the accumulation of NIX and BNIP3 mitophagy receptors.

To maintain both mitochondrial quality and quantity, cells selectively remove damaged or excessive mitochondria through mitophagy, which is a specialised form of autophagy. Mitophagy is induced in response to diverse conditions, including hypoxia, cellular differentiation and mitochondrial damage. However, the mechanisms that govern the removal of specific dysfunctional mitochondria under steady-state conditions to fine-tune mitochondrial content are not well understood.

Differential labeling of cell-surface and internalized proteins after antibody feeding of live cultured neurons.

In order to demonstrate the cell-surface localization of a putative transmembrane receptor in cultured neurons, we labeled the protein on the surface of live neurons with a specific primary antibody raised against an extracellular portion of the protein. Given that receptors are trafficked to and from the surface, if cells are permeabilized after fixation then both cell-surface and internal protein will be detected by the same labeled secondary antibody. Here, we adapted a method used to study protein trafficking ("antibody feeding") to differentially label protein that had been internalized by endocytosis during the antibody incubation step and protein that either remained on the cell surface or was trafficked to the surface during this period.

Epigenetic modifications in trinucleotide repeat diseases.

Accumulating evidence supports the important role for epigenetic changes in modulating clinical parameters of complex disorders, including neurodegenerative disease. Several conditions, including fragile X syndrome and Huntington's disease are caused by trinucleotide repeat (TNR) expansions in or near specific genes. Highlighting the link between epigenetic disruption and disease phenotype, recent studies have established significant correlations between clinical features, expansion size, gene expression, the chromatin profile, and DNA methylation in regions surrounding the TNR.

FXN methylation predicts expression and clinical outcome in Friedreich ataxia.

Objective: Friedreich ataxia (FA) is the most common ataxia and results from an expanded GAA repeat in the first intron of FXN. This leads to epigenetic modifications and reduced frataxin. We investigated the relationships between genetic, epigenetic, and clinical parameters in a large case-control study of FA.