Search results for "HTT protein"
showing 3 items of 3 documents
Pharmacological disruption of the MID1/α4 interaction reduces mutant Huntingtin levels in primary neuronal cultures.
2017
Expression of mutant Huntingtin (HTT) protein is central to the pathophysiology of Huntington's Disease (HD). The E3 ubiquitin ligase MID1 appears to have a key role in facilitating translation of the mutant HTT mRNA suggesting that interference with the function of this complex could be an attractive therapeutic approach. Here we describe a peptide that is able to disrupt the interaction between MID1 and the α4 protein, a regulatory subunit of protein phosphatase 2A (PP2A). By fusing this peptide to a sequence from the HIV-TAT protein we demonstrate that the peptide can disrupt the interaction within cells and show that this results in a decrease in levels of ribosomal S6 phosphorylation a…
A protein quality control pathway regulated by linear ubiquitination.
2019
Neurodegenerative diseases are characterized by the accumulation of misfolded proteins in the brain. Insights into protein quality control mechanisms to prevent neuronal dysfunction and cell death are crucial in developing causal therapies. Here, we report that various disease-associated protein aggregates are modified by the linear ubiquitin chain assembly complex (LUBAC). HOIP, the catalytic component of LUBAC, is recruited to misfolded Huntingtin in a p97/VCP-dependent manner, resulting in the assembly of linear polyubiquitin. As a consequence, the interactive surface of misfolded Huntingtin species is shielded from unwanted interactions, for example with the low complexity sequence doma…
Translation of HTT mRNA with expanded CAG repeats is regulated by the MID1-PP2A protein complex.
2012
Expansion of CAG repeats is a common feature of various neurodegenerative disorders, including Huntington's disease. Here we show that expanded CAG repeats bind to a translation regulatory protein complex containing MID1, protein phosphatase 2A and 40S ribosomal S6 kinase. Binding of the MID1-protein phosphatase 2A protein complex increases with CAG repeat size and stimulates translation of the CAG repeat expansion containing messenger RNA in a MID1-, protein phosphatase 2A- and mammalian target of rapamycin-dependent manner. Our data indicate that pathological CAG repeat expansions upregulate protein translation leading to an overproduction of aberrant protein and suggest that the MID1-com…