α-synuclein oligomers interact with ATP synthase and open the permeability transition pore in Parkinson's disease.

Protein aggregation causes α-synuclein to switch from its physiological role to a pathological toxic gain of function. Under physiological conditions, monomeric α-synuclein improves ATP synthase efficiency. Here, we report that aggregation of monomers generates beta sheet-rich oligomers that localise to the mitochondria in close proximity to several mitochondrial proteins including ATP synthase. Oligomeric α-synuclein impairs complex I-dependent respiration. Oligomers induce selective oxidation of the ATP synthase beta subunit and mitochondrial lipid peroxidation. These oxidation events increase the probability of permeability transition pore (PTP) opening, triggering mitochondrial swelling, and ultimately cell death. Notably, inhibition of oligomer-induced oxidation prevents the pathological induction of PTP. Inducible pluripotent stem cells (iPSC)-derived neurons bearing SNCA triplication, generate α-synuclein aggregates that interact with the ATP synthase and induce PTP opening, leading to neuronal death. This study shows how the transition of α-synuclein from its monomeric to oligomeric structure alters its functional consequences in Parkinson's disease

Linear domain interactome and biological function of anterior gradient 2

The Anterior Gradient 2 (AGR2) protein has been implicated in a variety of biological systems linked to cancer and metastasis, tamoxifen-induced drug resistance, pro-inflammatory diseases like IBD and asthma, and limb regeneration. The molecular mechanisms by which AGR2 mediates these various phenotypes in disease progression in both cancer and IBD are poorly understood, as is the biological function(s) of AGR2 under non-disease conditions. Here, we use a combination of biochemical techniques, organ culture, cell biology and mouse genetics to investigate the biological significance of AGR2 both in cell lines and in vivo. We present data based on phage-peptide inter-actomics screens suggesting a role for AGR2 in mediating the maturation and trafficking of a class of membrane and secretory proteins, and investigate a putative interaction between AGR2 and one member of this class of proteins. We also describe the construction of a universal vector for use in making a variety of transgenic animals, and then present data showing its use as a promoter reporter, and attempt to investigate the temporal and spatial expression of AGR2 in the developing and adult mouse. Further, we present data describing the localisation pattern of AGR2 in the developing murine kidney using a combination of organ culture and antibody staining, and suggest a role for AGR2 in the developing kidney based on this data that is in agreement with a chaperone function for membrane and secretory proteins. Together, these data suggest that AGR2 has an intrinsic consensus docking site for a subset of its client proteins, that AGR2 plays a role in protein maturation in ciliated cell types, and provides a novel biological model to dissect the role of AGR2 in ER-trafficking

Generation of pMULTIrec.

<p><b>A.</b> Four multisite Gateway compatible fragments (eGFPCre; IRES; puro^R and pA) were PCR amplified and cloned into the appropriate pDONR vector to make four pENTR vectors. <b>B.</b> The four pENTR clones were combined into one four-fragment Gateway clone. <b>C.</b> The four-fragment cassette was moved to pDONR/Zeo to change antibiotic resistance and subsequently sub-cloned to a vector carrying a Gateway ENTR cassette upstream of a dual selection (Neo/Kan) cassette. <b>D.</b> The resulting pMULTIrec vector.</p

The <i>Six2</i>-GCiP BAC construct made using pMULTIrec.

<p><b>A.</b> The four-fragment and dual selection cassette from pMULTIrec was cloned in a <i>Six2</i> containing BAC replacing the start codon. <b>B.</b> GFP imaging of a E13.5 embryo carrying the <i>Six2</i>-GCiP BAC. <b>C.</b> GFP imaging of whole mount E13.5 kidneys. <b>D.</b> E13.5 <i>Six2</i>-GCiP BAC kidneys cultured for four days showing GFP expression in the cap mesenchyme and Cdh1 expression in the ureteric bud.</p

Efficiency of the Gateway reactions used.

<p>Efficiency of the Gateway reactions used.</p