Publications by authors named "Michela Ciano"

The H1069Q substitution is the most frequent mutation of the Cu transporter ATP7B that causes Wilson disease in the Caucasian population. ATP7B localizes to the Golgi complex in hepatocytes, but, in the presence of excessive Cu, it relocates to the endo-lysosomal compartment to excrete Cu via bile canaliculi. In contrast, ATP7B-H1069Q is strongly retained in the ER, does not reach the Golgi complex and fails to move to the endo-lysosomal compartment in the presence of excessive Cu, thus causing toxic Cu accumulation.

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Article Synopsis
  • - The H1069Q mutation in the ATP7B copper transporter is common in Caucasian Wilson disease patients and disrupts copper transport in liver cells, leading to toxic accumulation of copper.
  • - In lab studies with induced pluripotent stem cells from patients, some ATP7B-H1069Q was able to reach the Golgi complex and respond to copper, which is contrary to previous findings in other cell types.
  • - The low expression of the mutant ATP7B-H1069Q, at only 20% of normal levels, is attributed to endoplasmic reticulum-associated degradation, highlighting the need to target this degradation process for potential therapies.
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Chronic lymphocytic leukaemia (CLL) is associated with apoptosis resistance and defective control of cell growth. Our study describes for the first time a critical role in CLL for the KRAB-zinc finger protein ZNF224. High ZNF224 transcript levels were detected in CLL patients with respect to control cells.

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We have previously shown that αB-crystallin (CRYAB), a small heat shock protein (sHsp) that prevents irreversible aggregation of unfolded protein by an ATP-independent chaperone activity, plays a pivotal role in the biogenesis of multipass transmembrane proteins (TMPs) assisting their folding from the cytosolic side of the endoplasmic reticulum (ER) (D'Agostino et al., 2013). Here we present evidence, based on phosphomimetic substitutions, that the three phosphorytable serine residues at position 19, 45 and 59 of CRYAB play a different regulatory role in this novel chaperone activity: S19 and S45 have a strong inhibitory effect, either alone or in combination, while S59 has not and counteracts the inhibition caused by single phosphomimetic substitutions at S19 and S45.

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KRAB-associated protein 1 (KAP1), the transcriptional corepressor of Kruppel-associated box zinc finger proteins (KRAB-ZFPs), is subjected to multiple post-translational modifications that are involved in fine-tuning of the multiple biological functions of KAP1. In previous papers, we analyzed the KAP1-dependent molecular mechanism of transcriptional repression mediated by ZNF224, a member of the KRAB-ZFP family, and identified the protein arginine methyltransferase PRMT5 as a component of the ZNF224 repression complex. We demonstrated that PRMT5-mediated histone arginine methylation is required to elicit ZNF224 transcriptional repression.

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