Gamma secretase orthologs are required for lysosomal activity and autophagic degradation in Dictyostelium discoideum, independent of PSEN (presenilin) proteolytic function. / Williams, Robin; Sharma, Devdutt; Otto, Grant; Warren, Eleanor; Beesley, Philip; King, Jason S.

In: Autophagy, 26.02.2019, p. 1-12.

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@article{6cdb47476aeb4f28acf6b7cd21910512,
title = "Gamma secretase orthologs are required for lysosomal activity and autophagic degradation in Dictyostelium discoideum, independent of PSEN (presenilin) proteolytic function",
abstract = "Mutations in the gamma-secretase complex are strongly associated with familial Alzheimer disease. Both proteolytic and non-proteolytic functions for the gamma-secretase complex have been previously described in mammalian model organisms, but their relative contributions to disease pathology remain unclear. Here, we dissect the roles of orthologs of the gamma-secretase components in the model system Dictyostelium, focusing on endocytosis, lysosomal activity and autophagy. In this model, we show that the orthologs of PSEN (psenA and psenB), Ncstn (nicastrin) and Aph-1 (gamma-secretase subunit Aph-1), are necessary for optimal fluid-phase uptake by macropinocytosis and in multicellular development under basic condition. Disruption of either psenA/B or Aph-1 proteins also leads disrupted phagosomal proteolysis as well as decreased autophagosomal acidification and autophagic flux. This indicates a general defect in lysosomal trafficking and degradation, which we show leads to the accumulation of ubiquitinated protein aggregates in cells lacking psenA/B and Aph-1 proteins. Importantly, we find that all the endocytic defects observed in Dictyostelium PSEN ortholog mutants can be fully rescued by proteolytically inactive Dictyostelium psenB and human PSEN1 proteins. Our data therefore demonstrates an evolutionarily conserved non-proteolytic role for presenilin, and gamma-secretase component orthologs, in maintaining Dictyostelium lysosomal trafficking and autophagy.",
keywords = "Alzheimers disease, presenilin, nicastrin, lysosomal trafficking, gamma-secretase, Dictyostelium , development, autophagy",
author = "Robin Williams and Devdutt Sharma and Grant Otto and Eleanor Warren and Philip Beesley and King, {Jason S.}",
year = "2019",
month = "2",
day = "26",
doi = "10.1080/15548627.2019.1586245",
language = "English",
pages = "1--12",
journal = "Autophagy",
issn = "1554-8627",
publisher = "Taylor and Francis",

}

RIS

TY - JOUR

T1 - Gamma secretase orthologs are required for lysosomal activity and autophagic degradation in Dictyostelium discoideum, independent of PSEN (presenilin) proteolytic function

AU - Williams, Robin

AU - Sharma, Devdutt

AU - Otto, Grant

AU - Warren, Eleanor

AU - Beesley, Philip

AU - King, Jason S.

PY - 2019/2/26

Y1 - 2019/2/26

N2 - Mutations in the gamma-secretase complex are strongly associated with familial Alzheimer disease. Both proteolytic and non-proteolytic functions for the gamma-secretase complex have been previously described in mammalian model organisms, but their relative contributions to disease pathology remain unclear. Here, we dissect the roles of orthologs of the gamma-secretase components in the model system Dictyostelium, focusing on endocytosis, lysosomal activity and autophagy. In this model, we show that the orthologs of PSEN (psenA and psenB), Ncstn (nicastrin) and Aph-1 (gamma-secretase subunit Aph-1), are necessary for optimal fluid-phase uptake by macropinocytosis and in multicellular development under basic condition. Disruption of either psenA/B or Aph-1 proteins also leads disrupted phagosomal proteolysis as well as decreased autophagosomal acidification and autophagic flux. This indicates a general defect in lysosomal trafficking and degradation, which we show leads to the accumulation of ubiquitinated protein aggregates in cells lacking psenA/B and Aph-1 proteins. Importantly, we find that all the endocytic defects observed in Dictyostelium PSEN ortholog mutants can be fully rescued by proteolytically inactive Dictyostelium psenB and human PSEN1 proteins. Our data therefore demonstrates an evolutionarily conserved non-proteolytic role for presenilin, and gamma-secretase component orthologs, in maintaining Dictyostelium lysosomal trafficking and autophagy.

AB - Mutations in the gamma-secretase complex are strongly associated with familial Alzheimer disease. Both proteolytic and non-proteolytic functions for the gamma-secretase complex have been previously described in mammalian model organisms, but their relative contributions to disease pathology remain unclear. Here, we dissect the roles of orthologs of the gamma-secretase components in the model system Dictyostelium, focusing on endocytosis, lysosomal activity and autophagy. In this model, we show that the orthologs of PSEN (psenA and psenB), Ncstn (nicastrin) and Aph-1 (gamma-secretase subunit Aph-1), are necessary for optimal fluid-phase uptake by macropinocytosis and in multicellular development under basic condition. Disruption of either psenA/B or Aph-1 proteins also leads disrupted phagosomal proteolysis as well as decreased autophagosomal acidification and autophagic flux. This indicates a general defect in lysosomal trafficking and degradation, which we show leads to the accumulation of ubiquitinated protein aggregates in cells lacking psenA/B and Aph-1 proteins. Importantly, we find that all the endocytic defects observed in Dictyostelium PSEN ortholog mutants can be fully rescued by proteolytically inactive Dictyostelium psenB and human PSEN1 proteins. Our data therefore demonstrates an evolutionarily conserved non-proteolytic role for presenilin, and gamma-secretase component orthologs, in maintaining Dictyostelium lysosomal trafficking and autophagy.

KW - Alzheimers disease

KW - presenilin

KW - nicastrin

KW - lysosomal trafficking

KW - gamma-secretase

KW - Dictyostelium

KW - development

KW - autophagy

U2 - 10.1080/15548627.2019.1586245

DO - 10.1080/15548627.2019.1586245

M3 - Article

SP - 1

EP - 12

JO - Autophagy

JF - Autophagy

SN - 1554-8627

ER -