TY - JOUR
T1 - Stress and aging induce distinct polyQ protein aggregation states
AU - Moronetti Mazzeo, Lorenza E.
AU - Dersh, Devin
AU - Boccitto, Marco
AU - Kalb, Robert G.
AU - Lamitina, Todd
PY - 2012/6/26
Y1 - 2012/6/26
N2 - Many age-related diseases are known to elicit protein misfolding and aggregation. Whereas environmental stressors, such as temperature, oxidative stress, and osmotic stress, can also damage proteins, it is not known whether aging and the environment impact protein folding in the same or different ways. Using polyQ reporters of protein folding in both Caenorhabditis elegans and mammalian cell culture, we show that osmotic stress, but not other proteotoxic stressors, induces rapid (minutes) cytoplasmic polyQ aggregation. Osmotic stress-induced polyQ aggregates could be distinguished from aging-induced polyQ aggregates based on morphological, biophysical, cell biological, and biochemical criteria, suggesting that they are a unique misfolded-protein species. The insulin-like growth factor signaling mutant daf-2, which inhibits age-induced polyQ aggregation and protects C. elegans from stress, did not prevent the formation of stress-induced polyQ aggregates. However, osmotic stress resistance mutants, which genetically activate the osmotic stress response, strongly inhibited the formation of osmotic polyQ aggregates. Our findings show that in vivo, the same protein can adopt distinct aggregation states depending on the initiating stressor and that stress and aging impact the proteome in related but distinct ways.
AB - Many age-related diseases are known to elicit protein misfolding and aggregation. Whereas environmental stressors, such as temperature, oxidative stress, and osmotic stress, can also damage proteins, it is not known whether aging and the environment impact protein folding in the same or different ways. Using polyQ reporters of protein folding in both Caenorhabditis elegans and mammalian cell culture, we show that osmotic stress, but not other proteotoxic stressors, induces rapid (minutes) cytoplasmic polyQ aggregation. Osmotic stress-induced polyQ aggregates could be distinguished from aging-induced polyQ aggregates based on morphological, biophysical, cell biological, and biochemical criteria, suggesting that they are a unique misfolded-protein species. The insulin-like growth factor signaling mutant daf-2, which inhibits age-induced polyQ aggregation and protects C. elegans from stress, did not prevent the formation of stress-induced polyQ aggregates. However, osmotic stress resistance mutants, which genetically activate the osmotic stress response, strongly inhibited the formation of osmotic polyQ aggregates. Our findings show that in vivo, the same protein can adopt distinct aggregation states depending on the initiating stressor and that stress and aging impact the proteome in related but distinct ways.
KW - Huntington disease
KW - Osmoregulation
KW - Polyglutamine
KW - Protein homeostasis
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U2 - 10.1073/pnas.1108766109
DO - 10.1073/pnas.1108766109
M3 - Article
C2 - 22645345
AN - SCOPUS:84862991002
SN - 0027-8424
VL - 109
SP - 10587
EP - 10592
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 26
ER -