Abstract
Vanadate, at concentrations higher than 0.04 mM, inhibits the intracellular degradation of short-lived proteins in exponentially growing L-132 human cells. The inhibition is not due to a decrease in viability or in the ATP contents of the cells. Since vanadate decreases proteolysis in cell extracts, the inhibition appears to affect the proteinases which degrade these proteins. Under optimal nutritional conditions, the degradation of long-lived proteins is accelerated by vanadate, thus providing additional evidence that in exponentially growing cultured cells degradation of short- and long-lived proteins occurs by different processes. Vanadate also efficiently inhibits the lysosomal degradation of endocytosed proteins and of long-lived proteins under step-down conditions. However, this effect seems to be unrelated to the observed inhibition of degradation of short-lived proteins, because chloroquine and leupeptin, which inhibit degradation of proteins by lysosomes, do not modify the degradation of these proteins. Our results provide for the first time a probe which, owing to its opposite effects on the degradation of short- and long-lived proteins, could be useful to clarify the mechanisms involved in protein degradation in cultured cells.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.