Decline in protease activities with age in the nematode Caenorhabditis elegans.
The activities of 3 lysosomal proteases in the nematode Caenorhabditis elegans are markedly lower in older animals. The aspartyl protease cathepsin D declines about 10-fold from day 3 (early adulthood) to day 11 (near the mean lifespan); this reflects a net decline in the amount of cathepsin D antigen. The specific activity of the thiol protease cathepsin Ce1 declines about 2.5-fold over the same period, and the specific activity of the thiol protease cathepsin Ce2 declines about 8-fold. The activity of a new non-lysosomal protease, designated cathepsin CeX, is invariant with age. The data are consistent with the hypothesis that reduced protease activity in older animals may cause a decline in the rate of protein turnover with age, but do not prove this hypothesis.
Sarkis
G J
GJ
Department of Biological Sciences, University of Pittsburgh, PA 15260.
Ashcom
J D
JD
Hawdon
J M
JM
Jacobson
L A
LA
D000375:Aging / Q000378:metabolism*; D000818:Animals; D002107:Caenorhabditis / Q000201:enzymology*; D002402:Cathepsin D / Q000378:metabolism; D002500:Centrifugation, Isopycnic; D015151:Immunoblotting; D007525:Isoelectric Focusing; D008247:Lysosomes / Q000201:enzymology*; D010447:Peptide Hydrolases / Q000378:metabolism*
D010447:Peptide Hydrolases; D002402:Cathepsin D