Margarida D Amaral

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We investigated in different human cell types nuclear positioning and transcriptional regulation of the functionally unrelated genes GASZ, CFTR, and CORTBP2, mapping to adjacent loci on human chromosome 7q31. When inactive, GASZ, CFTR, and CORTBP2 preferentially associated with the nuclear periphery and with perinuclear heterochromatin, whereas in their(More)
Allelic heterogeneity in disease-causing genes presents a substantial challenge to the translation of genomic variation into clinical practice. Few of the almost 2,000 variants in the cystic fibrosis transmembrane conductance regulator gene CFTR have empirical evidence that they cause cystic fibrosis. To address this gap, we collected both genotype and(More)
Biosynthesis and folding of multidomain transmembrane proteins is a complex process. Structural fidelity is monitored by endoplasmic reticulum (ER) quality control involving the molecular chaperone calnexin. Retained misfolded proteins undergo ER-associated degradation (ERAD) through the ubiquitin-proteasome pathway. Our data show that the major degradation(More)
Cystic fibrosis is mostly caused by the F508del mutation, which impairs CFTR protein from exiting the endoplasmic reticulum due to misfolding. VX-809 is a small molecule that rescues F508del-CFTR localization, which recently went into clinical trial but with unknown mechanism of action (MoA). Herein, we assessed if VX-809 is additive or synergistic with(More)
The autosomal recessive disease cystic fibrosis (CF) is caused by mutations in the gene coding for the CF transmembrane conductance regulator (CFTR) protein, a cAMP-activated chloride channel expressed at the apical membrane of epithelial cells. Although about 1000 different mutations have been identified, most CF patients carry the F508del mutation in at(More)
With the discovery of the CFTR gene in 1989, the search for therapies to improve the basic defects of cystic fibrosis (CF) commenced. Pharmacological manipulation provides the opportunity to enhance CF transmembrane conductance regulator (CFTR) protein synthesis and/or function. CFTR modulators include potentiators to improve channel gating (class III(More)
Massive production and accumulation of a single abnormal protein may constitute a major toxic burden for the cell and even compromise the organism's long-term viability. Consequently, adaptation and survival have forced evolution to create ‘quality control’ mechanisms that detect, monitor, and often degrade such abnormally folded gene products, in which(More)
Protein homeostasis maintains proper intracellular balance by promoting protein folding and clearance mechanisms while minimizing the stress caused by the accumulation of misfolded and damaged proteins. Chronic expression of aggregation-prone proteins is deleterious to the cell and has been linked to a wide range of conformational disorders. The molecular(More)
Present state of knowledge, mostly based on heterologous expression studies, indicates that the cystic fibrosis transmembrane conductance regulator (CFTR) protein bearing the F508del mutation is misprocessed and mislocalized in the cytoplasm, unable to reach the cell surface. Recently, however, it was described that protein levels and localization are(More)
One of the major challenges facing the pharmaceutical field is the identification of novel, 'druggable' targets common to distinct diseases that, despite their clinical diversity, share the same basic molecular defect(s) - thus, being termed 'horizontal diseases'. Membrane proteins constitute one of the largest families in the human genome and, given their(More)