Abstract
Activities of three lysosomal enzymes--acid RNase. N-acetyl-beta-D-glucosaminidase and acid phosphatase--were determined during the growth cycles of WI-38 and HeLa cells, as well as in radiation-arrested WI-38 cells. In confluent and growth-arrested cultures of WI-38 cells, the lysosomal RNase increased six- to sevenfold; glucosaminidase, four- to fivefold; and phosphatase, two- to threefold. In HeLa cells, the lysosomal enzymes also increased in confluent cultures, but less than twofold; and the RNase level increased only transiently. In both WI-38 and HeLa cells, the rate of RNA breakdown also increased as cultures approached confluency. The rate of turnover of RNA, like the level of acid RNase, was higher in WI-38 cells than in HeLa cells (4 d half-life compared to 8 d). The increase in acid RNase could be prevented by incubation of cells in NH4Cl, but the rate of turnover in the presence of NH4Cl increased just as much when cells became confluent or stopped growth. The content of acid RNase could be changed more than 10-fold without altering the rate of RNA turnover. It is suggested that the increase in enzyme level is more important for possible autophagy or increased digestion of engulfed RNA, rather than for normal RNA t...Continue Reading
References
Jan 1, 1976·Archives of Biochemistry and Biophysics·C C Wang, O Touster
Jun 29, 1978·Biochemical and Biophysical Research Communications·D J HalleyH Galjaard
Sep 1, 1975·Archives of Biochemistry and Biophysics·A S SunL Packer
Dec 1, 1976·Archives of Biochemistry and Biophysics·P SchlesingerP Stahl
Jan 1, 1978·Cell·S A LiebhaberD Schlessinger
Apr 2, 1979·European Journal of Biochemistry·P O SeglenA E Solheim
Mar 15, 1978·Experimental Cell Research·S A Liebhaber, D Schlessinger
Apr 30, 1978·Archives of Biochemistry and Biophysics·J Kaplan
Jan 1, 1977·Journal of Cellular Physiology·R MarzJ R Sheppard
Dec 1, 1976·Archives of Biochemistry and Biophysics·P StahlP Schlesinger
Dec 18, 1975·Nature·U K EhmannJ T Lett
Nov 1, 1969·Proceedings of the National Academy of Sciences of the United States of America·D D Cunningham, A B Pardee
Sep 1, 1971·The Journal of Pediatrics·J G LeroyA C Crocker
Nov 1, 1974·The Journal of Cell Biology·P TulkensA Trouet
Feb 1, 1974·Journal of Cellular Physiology·A Horvat, G Acs
Jan 1, 1972·Experimental Cell Research·C A RyanH L Nadler
Apr 1, 1971·Journal of Cellular Physiology·M J Weber, H Rubin
Nov 1, 1971·Proceedings of the Society for Experimental Biology and Medicine·A Maciera-CoelhoM Adrian
Aug 1, 1970·Experimental Cell Research·D E Comings, T A Okada
Jun 1, 1967·Journal of Cellular Physiology·V J CristofaloD Kritchevsky
Jan 1, 1981·Molecular and Cellular Biology·M SameshimaD Schlessinger
Citations
Mar 1, 1986·Chemico-biological Interactions·J MalecB Czartoryska
Jul 1, 1983·Journal of Cellular Physiology·H Saeki, A Oikawa
Nov 29, 1983·Biochimica Et Biophysica Acta·R D Kenagy, E L Bierman