Intracellular accumulation of misfolded proteins causes toxic proteinopathies, diseases without targeted therapies. Mucin 1 kidney disease (MKD) results from a frameshift mutation in the MUC1 gene (MUC1-fs). Here, we show that MKD is a toxic proteinopathy. Intracellular MUC1-fs accumulation activated the ATF6 unfolded protein response (UPR) branch. We identified BRD4780, a small molecule that clears MUC1-fs from patient cells, from kidneys of knockin mice and from patient kidney organoids. MUC1-fs is trapped in TMED9 cargo receptor-containing vesicles of the early secretory pathway. BRD4780 binds TMED9, releases MUC1-fs, and re-routes it for lysosomal degradation, an effect phenocopied by TMED9 deletion. Our findings reveal BRD4780 as a promising lead for the treatment of MKD and other toxic proteinopathies. Generally, we elucidate a novel mechanism for the entrapment of misfolded proteins by cargo receptors and a strategy for their release and anterograde trafficking to the lysosome.

• MeSH
• benzamidy chemie   metabolismus   farmakologie   MeSH
• epitelové buňky cytologie   metabolismus   MeSH
• imidazolinové receptory antagonisté a inhibitory   genetika   metabolismus   MeSH
• indukované pluripotentní kmenové buňky cytologie   metabolismus   MeSH
• ledviny cytologie   metabolismus   patologie   MeSH
• lidé MeSH
• lyzozomy metabolismus   MeSH
• malá interferující RNA metabolismus   MeSH
• mucin 1 chemie   genetika   metabolismus   MeSH
• myši transgenní MeSH
• myši MeSH
• nemoci ledvin metabolismus   patologie   MeSH
• posunová mutace MeSH
• RNA interference MeSH
• signální dráha UPR účinky léků   MeSH
• transkripční faktor ATF6 metabolismus   MeSH
• vezikulární transportní proteiny chemie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Glycosylation abnormalities have been observed in autoimmune diseases and cancer. Here, we compare mechanisms of aberrant O-glycosylation, i.e., formation of Tn and sialyl-Tn structures, on MUC1 in breast cancer, and on IgA1 in an autoimmune disease, IgA nephropathy. The pathways of aberrant O-glycosylation, although different for MUC1 and IgA1, include dysregulation in glycosyltransferase expression, stability, and/or intracellular localization. Moreover, these aberrant glycoproteins are recognized by antibodies, although with different consequences. In breast cancer, elevated levels of antibodies recognizing aberrant MUC1 are associated with better outcome, whereas in IgA nephropathy, the antibodies recognizing aberrant IgA1 are part of the pathogenetic process.

• MeSH
• adenokarcinom imunologie   MeSH
• glykosylace MeSH
• IgA nefropatie imunologie   MeSH
• imunoglobulin A chemie   imunologie   MeSH
• lidé MeSH
• molekulární sekvence - údaje MeSH
• mucin 1 chemie   imunologie   MeSH
• nádory prsu imunologie   MeSH
• polysacharidy chemie   imunologie   MeSH
• protilátky chemie   imunologie   MeSH
• prsy imunologie   MeSH
• sacharidové sekvence MeSH
• sekvence aminokyselin MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Research Support, N.I.H., Extramural MeSH